[CLJ-1517] Unrolled small vectors Created: 01/Sep/14  Updated: 18/May/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: Backlog

Type: Enhancement Priority: Critical
Reporter: Zach Tellman Assignee: Unassigned
Resolution: Unresolved Votes: 25
Labels: collections, performance

Attachments: File unrolled-collections-2.diff     File unrolled-collections.diff     Text File unrolled-vector-2.patch     Text File unrolled-vector.patch    
Patch: Code
Approval: Incomplete

 Description   

As discussed on the mailing list [1], this patch has two unrolled variants of vectors and maps, with special inner classes for each cardinality. Currently both grow to six elements before spilling over into the general versions of the data structures, which is based on rough testing but can be easily changed. At Rich's request, I haven't included any integration into the rest of the code, and there are top-level static create() methods for each.

The sole reason for this patch is performance, both in terms of creating data structures and performing operations on them. This can be seen as a more verbose version of the trick currently played with PersistentArrayMap spilling over into PersistentHashMap. Based on the benchmarks, which can be run by cloning cambrian-collections [2] and running 'lein test :benchmark', this should supplant PersistentArrayMap. Performance is at least on par with PAM, and often much faster. Especially noteworthy is the creation time, which is 5x faster for maps of all sizes (lein test :only cambrian-collections.map-test/benchmark-construction), and on par for 3-vectors, but 20x faster for 5-vectors. There are similar benefits for hash and equality calculations, as well as calls to reduce().

This is a big patch (over 5k lines), and will be kind of a pain to review. My assumption of correctness is based on the use of collection-check, and the fact that the underlying approach is very simple. I'm happy to provide a high-level description of the approach taken, though, if that will help the review process.

I'm hoping to get this into 1.7, so please let me know if there's anything I can do to help accomplish that.

[1] https://groups.google.com/forum/#!topic/clojure-dev/pDhYoELjrcs
[2] https://github.com/ztellman/cambrian-collections

Patch: unrolled-vector-2.patch

Screener Notes: The approach is clear and understandable. Given the volume of generated code, I believe that best way to improve confidence in this code is to get people using it asap, and add collection-test [3] to the Clojure test suite. I would also like to get the generator [4] included in the Clojure repo. We don't need to necessarily automate running it, but would be nice to have it nearby if we want to tweak something later.

[3] https://github.com/ztellman/collection-check/blob/master/src/collection_check.clj
[4] https://github.com/ztellman/cambrian-collections/blob/master/generate/cambrian_collections/vector.clj



 Comments   
Comment by Zach Tellman [ 01/Sep/14 10:13 PM ]

Oh, I forgot to mention that I didn't make a PersistentUnrolledSet, since the existing wrappers can use the unrolled map implementation. However, it would be moderately faster and more memory efficient to have one, so let me know if it seems worthwhile.

Comment by Nicola Mometto [ 02/Sep/14 5:23 AM ]

Zach, the patch you added isn't in the correct format, they need to be created using `git format-patch`

Comment by Nicola Mometto [ 02/Sep/14 5:31 AM ]

Also, I'm not sure if this is on-scope with the ticket but those patches break with *print-dup*, as it expects a static create(x) method for each inner class.

I'd suggest adding a create(Map x) static method for the inner PersistentUnrolledMap classes and a create(ISeq x) one for the inner PersistentUnrolledVector classes

Comment by Alex Miller [ 02/Sep/14 8:14 AM ]

Re making patches, see: http://dev.clojure.org/display/community/Developing+Patches

Comment by Jozef Wagner [ 02/Sep/14 9:16 AM ]

I wonder what is the overhead of having meta and 2 hash fields in the class. Have you considered a version where the hash is computed on the fly and where you have two sets of collections, one with meta field and one without, using former when the actual metadata is attached to the collection?

Comment by Zach Tellman [ 02/Sep/14 12:13 PM ]

I've attached a patch using the proper method. Somehow I missed the detailed explanation for how to do this, sorry. I know the guidelines say not to delete previous patches, but since the first one isn't useful I've deleted it to minimize confusion.

I did the print-dup friendly create methods, and then realized that once these are properly integrated, 'pr' will just emit these as vectors. I'm fairly sure the create methods aren't necessary, so I've commented them out, but I'm happy to add them back in if they're useful for some reason I can't see.

I haven't given a lot of thought to memory efficiency, but I think caching the hashes are worthwhile. I can see an argument for creating a "with-meta" version of each collection, but since that would double the size of an already enormous patch, I think that should probably wait.

Comment by Zach Tellman [ 03/Sep/14 4:31 PM ]

I found a bug! Like PersistentArrayMap, I have a special code path for comparing keywords, but my generators for collection-check were previously using only integer keys. There was an off-by-one error in the transient map implementation [1], which was not present for non-keyword lookups.

I've taken a close look for other gaps in my test coverage, and can't find any. I don't think this substantively changes the risk of this patch (an updated version of which has been uploaded as 'unrolled-collections-2.diff'), but obviously where there's one bug, there may be others.

[1] https://github.com/ztellman/cambrian-collections/commit/eb7dfe6d12e6774512dbab22a148202052442c6d#diff-4bf78dbf5b453f84ed59795a3bffe5fcR559

Comment by Zach Tellman [ 03/Oct/14 2:34 PM ]

As an additional data point, I swapped out the data structures in the Cheshire JSON library. On the "no keyword-fn decode" benchmark, the current implementation takes 6us, with the unrolled data structures takes 4us, and with no data structures (just lexing the JSON via Jackson) takes 2us. Other benchmarks had similar results. So at least in this scenario, it halves the overhead.

Benchmarks can be run by cloning https://github.com/dakrone/cheshire, unrolled collections can be tested by using the 'unrolled-collections' branch. The pure lexing benchmark can be reproduced by messing around with the cheshire.parse namespace a bit.

Comment by Zach Tellman [ 06/Oct/14 1:31 PM ]

Is there no way to get this into 1.7? It's an awfully big win to push off for another year.

Comment by Alex Miller [ 07/Oct/14 2:08 PM ]

Hey Zach, it's definitely considered important but we have decided to drop almost everything not fully done for 1.7. Timeframe for following release is unknown, but certainly expected to be significantly less than a year.

Comment by John Szakmeister [ 30/Oct/14 2:53 PM ]

You are all free to determine the time table, but I thought I'd point out that Zach is not entirely off-base. Clojure 1.4.0 was released April 5th, 2012. Clojure 1.5.0 was released March 1st, 2013 with 1.6.0 showing up March 25th, 2014. So it appears that the current cadence is around a year.

Comment by Alex Miller [ 30/Oct/14 3:40 PM ]

John, there is no point to comments like this. Let's please keep issue comments focused on the issue.

Comment by Zach Tellman [ 13/Nov/14 12:23 PM ]

I did a small write-up on this patch which should help in the eventual code review: http://blog.factual.com/using-clojure-to-generate-java-to-reimplement-clojure

Comment by Zach Tellman [ 07/Dec/14 10:34 PM ]

Per my conversation with Alex at the Conj, here's a patch that only contains the unrolled vectors, and uses the more efficient constructor for PersistentVector when spilling over.

Comment by Alex Miller [ 08/Dec/14 1:10 PM ]

Zach, I created a new placeholder for the map work at http://dev.clojure.org/jira/browse/CLJ-1610.

Comment by Jean Niklas L'orange [ 09/Dec/14 1:52 PM ]

It should probably be noted that core.rrb-vector will break for small vectors by this patch, as it peeks into the underlying structure. This will also break other libraries which peeks into the vector implementation internals, although I'm not aware of any other – certainly not any other contrib library.

Also, two comments on unrolled-vector.patch:

private transient boolean edit = true;
in the Transient class should probably be
private volatile boolean edit = true;
as transient means something entirely different in Java.

conj in the Transient implementation could invalidate itself without any problems (edit = false;) if it is converted into a TransientVector (i.e. spills over) – unless it has a notable overhead. The invalidation can prevent some subtle bugs related to erroneous transient usage.

Comment by Alex Miller [ 09/Dec/14 1:58 PM ]

Jean - understanding the scope of the impact will certainly be part of the integration process for this patch. I appreciate the heads-up. While we try to minimize breakage for things like this, it may be unavoidable for libraries that rely on implementation internals.

Comment by Michał Marczyk [ 09/Dec/14 2:03 PM ]

I'll add support for unrolled vectors to core.rrb-vector the moment they land on master. (Probably with some conditional compilation so as not to break compatibility with earlier versions of Clojure – we'll see when the time comes.)

Comment by Michał Marczyk [ 09/Dec/14 2:06 PM ]

I should say that it'd be possible to add generic support for any "vector lookalikes" by pouring them into regular vectors in linear time. At first glance it seems to me that that'd be out of line with the basic promise of the library, but I'll give it some more thought before the changes actually land.

Comment by Zach Tellman [ 09/Dec/14 5:43 PM ]

Somewhat predictably, the day after I cut the previous patch, someone found an issue [1]. In short, my use of the ArrayChunk wrapper applied the offset twice.

This was not caught by collection-check, which has been updated to catch this particular failure. It was, however, uncovered by Michael Blume's attempts to merge the change into Clojure, which tripped a bunch of alarms in Clojure's test suite. My own attempt to do the same to "prove" that it worked was before I added in the chunked seq functionality, hence this issue persisting until now.

As always, there may be more issues lurking. I hope we can get as many eyeballs on the code between now and 1.8 as possible.

[1] https://github.com/ztellman/cambrian-collections/commit/2e70bbd14640b312db77590d8224e6ed0f535b43
[2] https://github.com/MichaelBlume/clojure/tree/test-vector

Comment by Zach Tellman [ 10/Jul/15 1:54 PM ]

As a companion to the performance analysis in the unrolled map issue, I've run the benchmarks and posted the results at https://gist.github.com/ztellman/10e8959501fb666dc35e. Some notable results:

Comment by Alex Miller [ 13/Jul/15 9:02 AM ]

Stu: I do not think this patch should be marked "screened" until the actual integration and build work (if the generator is integrated) has been completed.

Comment by Alex Miller [ 14/Jul/15 4:33 PM ]

FYI, we have "reset" all big features for 1.8 for the moment (except the socket repl work). We may still include it - that determination will be made later.

Comment by Zach Tellman [ 14/Jul/15 4:43 PM ]

Okay, any idea when the determination will be made? I was excited that we seemed to be finally moving forward on this.

Comment by Alex Miller [ 14/Jul/15 4:51 PM ]

No, but it is now on my work list.

Comment by Rich Hickey [ 15/Jul/15 8:17 AM ]

I wonder if all of the overriding of APersistentVector yields important benefits - e.g. iterator, hashcode etc.

Comment by Zach Tellman [ 15/Jul/15 11:51 AM ]

In the case of hashcode, definitely: https://gist.github.com/ztellman/10e8959501fb666dc35e#file-gistfile1-txt-L1013-L1076. This was actually one of the original things I wanted to speed up.

In the case of the iterator, probably not. I'd be fine removing that.

Comment by Zach Tellman [ 16/Jul/15 5:17 PM ]

So am I to infer from https://github.com/clojure/clojure/commit/36d665793b43f62cfd22354aced4c6892088abd6 that this issue is defunct? If so, I think there's a lot of improvements being left on the table for no particular reason.

Comment by Rich Hickey [ 16/Jul/15 6:34 PM ]

Yes, that commit covers this functionality. It takes a different approach from the patch in building up from a small core, and maximizing improvements to the bases rather than having a lot of redundant definitions per class. That also allowed for immediate integration without as much concern for correctness, as there is little new code. It also emphasizes the use case for tuples, e.g. small vectors used as values that won't be changed, thus de-emphasizing the 'mutable' functions. I disagree that many necessary improvements are being left out. The patch 'optimized' many things that don't matter. Further, there are not big improvements to the pervasive inlining. In addition, the commit includes the integration work at a fraction of the size of the patch. In all, it would have taken much more back and forth to get the patch to conform with this approach than to just get it all done, but I appreciate the inspiration and instigation - thanks!

Comment by Rich Hickey [ 16/Jul/15 6:46 PM ]

That said, this commit need not be the last word - it can serve as a baseline for further optimization. But I'd rather that be driven by need. Clojure could become 10x as large optimizing things that don't matter.

Comment by Zach Tellman [ 19/Jul/15 1:36 PM ]

What is our reference for "relevant" performance? I (or anyone else) can provide microbenchmarks for calculating hashes or whatever else, but that doesn't prove that it's an important improvement. I previously provided benchmarks for JSON decoding in Cheshire, but that's just one of many possible real-world benchmarks. It might be useful to have an agreed-upon list of benchmarks that we can use when debating what is and isn't useful.

Comment by Mike Anderson [ 19/Jul/15 11:14 PM ]

I was interested in this implementation so created a branch that integrates Zach's unrolled vectors on top of clojure 1.8.0-alpha2. I also simplified some of the code (I don't think the metadata handling or unrolled seqs are worthwhile, for example)

Github branch: https://github.com/mikera/clojure/tree/clj-1517

Then I ran a set of micro-benchmarks created by Peter Taoussanis

Results: https://gist.github.com/mikera/72a739c84dd52fa3b6d6

My findings from this testing:

  • Performance is comparable (within +/- 20%) on the majority of tests
  • Zach's approach is noticeably faster (by 70-150%) for 4 operations (reduce, mapv, into, equality)

My view is that these additional optimisations are worthwhile. In particular, I think that reduce and into are very important operations. I also care about mapv quite a lot for core.matrix (It's fundamental to many numerical operations on arrays implemented using Clojure vectors).

Happy to create a patch along these lines if it would be acceptable.

Comment by Zach Tellman [ 19/Jul/15 11:45 PM ]

The `reduce` improvements are likely due to the unrolled reduce and kvreduce impls, but the others are probably because of the unrolled transient implementation. The extra code required to add these would be pretty modest.

Comment by Mike Anderson [ 20/Jul/15 9:20 PM ]

I actually condensed the code down to a single implementation for `Transient` and `TupleSeq`. I don't think these really need to be fully unrolled for each Tuple type. That helps by making the code even smaller (and probably also helps performance, given JVM inline caching etc.)

Comment by Peter Taoussanis [ 21/Jul/15 11:46 AM ]

Hey folks,

Silly question: is there actually a particular set of reference benchmarks that everyone's currently using to test the work on tuples? It took me a while to notice how bad the variance was with my own set of micro benchmarks.

Bumping all the run counts up till the noise starts ~dying down, I'm actually seeing numbers now that don't seem to agree with others here .

Google Docs link: https://docs.google.com/spreadsheets/d/1QHY3lehVF-aKrlOwDQfyDO5SLkGeb_uaj85NZ7tnuL0/edit?usp=sharing
gist with the benchmarks: https://gist.github.com/ptaoussanis/0a294809bc9075b6b02d

Thanks, cheers!

Comment by Zach Tellman [ 21/Jul/15 6:52 PM ]

Hey Peter, I can't reproduce your results, and some of them are so far off what I'd expect that I have to think there was some data gathering error. For instance, the assoc operation being slower is kind of inexplicable, considering the unrolled version doesn't do any copying, etc. Also, all of your numbers are significantly slower than the ones on my 4 year old laptop, which is also a bit strange.

Just to make sure that we're comparing apples to apples, I've adapted your benchmarks into something that pretty-prints the mean runtime and variance for 1.7, 1.8-alpha2, and Mike's 1517 fork. It can be found at https://github.com/ztellman/tuple-benchmark, and the results of a run at https://gist.github.com/ztellman/3701d965228fb9eda084.

Comment by Mike Anderson [ 22/Jul/15 2:24 AM ]

Hey Zach just looked at your benchmarks and they are definitely more consistent with what I am seeing. The overall nanosecond timings look about right from my experience with similar code (e.g. working with small vectors in vectorz-clj).

Comment by Peter Taoussanis [ 22/Jul/15 2:41 AM ]

Hi Zach, thanks for that!

Have updated the results -
Gist: https://gist.github.com/ptaoussanis/0a294809bc9075b6b02d
Google docs: https://goo.gl/khgT83

Note that I've added an extra sheet/tab to the Google doc for your own numbers at https://gist.github.com/ztellman/3701d965228fb9eda084.

Am still struggling to produce results that show any consistent+significant post-JIT benefit to either of the tuple implementations against the micro benchmarks and one larger small-vec-heavy system I had handy.

It's looking to me like it's maybe possible that the JIT's actually optimising away most of the non-tuple inefficiencies in practice?

Of course it's very possible that my results are off, or my expectations wrong. The numbers have been difficult to pin down.

It definitely helped to have a standardised reference micro benchmark to work against (https://github.com/ztellman/tuple-benchmark). Could I perhaps suggest a similar reference macro benchmark (maybe something from core.matrix, Mike?)

Might also be a good idea to define a worthwhile target performance delta for ops like these that run in the nanosecond range (or for the larger reference macro benchmark)?

Just some thoughts from someone passing through in case they're at all useful; know many of you have been deeply involved in this for some time so please feel free to ignore any input that's not helpful

Appreciate all the efforts, cheers!

Comment by Rich Hickey [ 22/Jul/15 9:24 AM ]

I think everyone should back off on their enthusiasm for this approach. After much analysis, I am seeing definite negative impacts to tuples, especially the multiple class approach proposed by Zach. What happens in real code is that the many tuple classes cause call sites that see different sized vectors to become megamorphic, and nothing gets adequately optimized. In particular, call sites that will see tuple-sized and large vectors (i.e. a lot of library code) will optimize differently depending upon which they see often first. So, if you run your first tight loop on vector code that sees tuples, that code could later do much worse (50-100%) on large vectors than before the tuples patch was in place. Being much slower on large collections is a poor tradeoff for being slightly faster on small ones.

Certainly different tuple classes for arity 0-6 is a dead idea. You get as good or better optimization (at some cost in size) from a single class e.g. one with four fields, covering sizes 0-4. I have a working version of this in a local branch. It is better in that sites that include pvectors are only bi-morphic, but I am still somewhat skittish given what I've seen.

The other takeaway is that the micro benchmarks are nearly worthless for detecting these issues.

Comment by Zach Tellman [ 22/Jul/15 11:07 AM ]

I'm pretty sure that all of my real-world applications of the tuples (via clj-tuple) have been fixed cardinality, and wouldn't have surfaced any such issue. Thanks for putting the idea through its paces.

Comment by Mike Anderson [ 22/Jul/15 10:37 PM ]

Rich these are good insights - do you have a benchmark that you are using as representative of real world code?

I agree that it is great if we can avoid call sites becoming megamorphic, though I also believe the ship has sailed on that one already when you consider the multiple types of IPersistentVector that already exist (MapEntry, PersistentVector, SubVector plus any library-defined IPersistentVector instances such as clojure.core.rrb-vector). As a consequence, the JVM is usually not going to be able to prove that a specific IPersistentVector interface invocation is monomorphic, which is when the really big optimisations happen.

In most of the real world code that I've been working with, the same size/type of vector gets used repeatedly (Examples: iterating over map entries, working with a sequence of size-N vectors), so in such cases we should be able to rely on the polymorphic inline cache doing the right thing.

The idea of a single Tuple class for sizes 0-4 is interesting, though I can't help thinking that a lot of the performance gain from this may stem from the fact that a lot of code does stuff like (reduce conj [] .....) or the transient equivalent which is a particularly bad use case for Tuples, at least from the call site caching perspective. There may be a better way to optimise such cases rather than simply trying to make Tuples faster.... e.g. calling asTransient() on a Tuple0 could perhaps switch straight into the PersistentVector implementation.

Comment by Colin Fleming [ 18/May/16 8:32 PM ]

Here's a relevant issue from Google's Guava project, where they also found serious performance degradation with fixed-size collections: https://github.com/google/guava/issues/1268. It has a lot of interesting detail about how the performance breaks down.





[CLJ-1522] Enhance multimethods metadata Created: 08/Sep/14  Updated: 26/Jan/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Enhancement Priority: Critical
Reporter: Bozhidar Batsov Assignee: Unassigned
Resolution: Unresolved Votes: 21
Labels: metadata

Approval: Triaged

 Description   

I think that multimethod metadata can be extended a bit with some property indicating the var in question is referring to a multimethod (we have something similar for macros) and some default arglists property.

I'm raising this issue because as a tool writer (CIDER) I'm having hard time determining if something is a multimethod (I have to resort to code like (instance? clojure.lang.MultiFn obj) which is acceptable, but not ideal I think (compared to macros and special forms)). There's also the problem that I cannot provide the users with eldoc (function signature) as it's not available in the metadata (this issue was raised on the mailing list as well https://groups.google.com/forum/#!topic/clojure/crje_RLTWdk).

I feel that we really have a problem with the missing arglist and we should solve it somehow. I'm not sure I'm suggesting the best solution and I'll certainly take any solution.



 Comments   
Comment by Bozhidar Batsov [ 09/Sep/14 4:24 AM ]

Btw, I failed to mention this as I thought it was obvious, but I think we should use the dispatch function's arglist in the multimethod metadata.





[CLJ-706] make use of deprecated namespaces/vars easier to spot Created: 05/Jan/11  Updated: 20/Sep/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Critical
Reporter: Stuart Halloway Assignee: Cezary Kosko
Resolution: Unresolved Votes: 25
Labels: errormsgs

Attachments: File 706-deprecated-ns-var-warnings-tested-2.diff     File 706-deprecated-ns-var-warnings-tested-3.diff     File 706-deprecated-ns-var-warnings-tested.diff     File 706-deprecated-var-warning.diff     Text File 706-deprecated-var-warning-patch-v2.txt     File 706-fix-deprecation-warnings-agents.diff     File 706-fix-deprecation-warnings-on-replicate.diff     File 706-fix-deprecation-warning-test-junit.diff     File 706-warning-on-deprecated-ns.diff    
Approval: Prescreened

 Description   

From the mailing list http://groups.google.com/group/clojure/msg/c41d909bd58e4534. It is easy to use deprecated namespaces or vars without knowing you are doing so. The documentation warnings are small, and there is no compiler warning.

Proposed:

  • Add new *warn-on-deprecated* dynamic var, defaulted to false
  • Warn to stderr when {:deprecated true} namespace is loaded.
  • Warn to stderr when {:deprecated true} var is analyzed.
  • Warn to stderr when {:deprecated true} macro is expanded.
  • New system property clojure.compiler.warn-on-deprecated
  • Compile Clojure itself with clojure.compiler.warn-on-deprecated
  • Fix deprecation warnings inside Clojure (replicate, clear-agent-errors)
  • Mark clojure.parallel as deprecated with :deprecation tag

Examples:

(set! *warn-on-deprecated* true)

;; use of a deprecated var (on compile)
(defn ^:deprecated f [x] x)
(f 5)
;;=> Deprecation warning, NO_SOURCE_PATH:7:1 : var #'user/f is deprecated

;; use of a deprecated macro (on macro expansion)
(defmacro ^:deprecated m [x] x)
(m 5)
;;=> Deprecation warning, NO_SOURCE_PATH:7:1 : macro #'user/m is deprecated

;; use of a deprecated namespace (on load)
(ns foo {:deprecated "1.1"})
(ns bar (:require foo))
;;=> Deprecation warning: loading deprecated namespace `foo` from namespace `bar`

Patch: 706-deprecated-ns-var-warnings-tested-3.diff

Questions: Should default for deprecation warnings be true instead? People upgrading are likely to see new warnings which might be surprising.

  • Should default be to warn or not warn on deprecated?


 Comments   
Comment by Rich Hickey [ 07/Jan/11 9:38 AM ]

I don't mind warning to stderr

Comment by Luke VanderHart [ 26/Oct/12 1:37 PM ]

706-deprecated-var-warning.diff adds warnings when using deprecated vars. The other three patches clean up deprecation warnings.

Comment by Andy Fingerhut [ 26/Oct/12 2:23 PM ]

Great stuff. I looked through the first patch, and didn't see anything in there that lets someone disable deprecation warnings from the command line, the way that warn-on-reflection can today be set to true with a command line option.

Is that something important to have for deprecation warnings?

Comment by Andy Fingerhut [ 28/Oct/12 4:57 PM ]

I was hoping it would be quick and easy to add source file, line, and column info to the deprecation warning messages. It isn't as easy as adding them to the format() call, because the method analyzeSymbol doesn't receive these values as args. Is this deprecation check being done in a place where it is not easy to relate it to the source file, line, and column? Could it be done in a place where that info is easily available?

Comment by Ghadi Shayban [ 29/Oct/12 1:02 AM ]

Another patch - this time to warn on loading deprecated namespaces, instead of vars. This patch requires the first one.

Re: line/column, I'll figure out how to thread the compile context through if it's desired.

Re: Compile flag. I have a patch for this also, but I'm still verifying how to invoke. How is warn-on-reflection set by command line?

Comment by Andy Fingerhut [ 29/Oct/12 1:43 AM ]

Re: Compile flag. Don't hold off on implementing a flag if you want to, but it might be worth hearing from others whether such a command line option is even desired. I was asking in hopes of eliciting such a response.

For the way that it is handled in the Clojure compiler, search for REFLECTION_WARNING_PROP and related code in Compile.java. If you invoke the Clojure compiler directly via a Java command line, use -Dclojure.compile.warn-on-reflection=true (default is false). See the recent email thread sent to Clojure Dev Google group if you want to know how to do it via ant or Maven. Link: https://mail.google.com/mail/?shva=1#label/clojure-dev/13aa0e34530196c3

There is also a separate command-line flag called compiler-options (see Compile.java) that is implemented as a map inside the compiler. It was added more recently than warn-on-reflection, and might be the preferred method to add more such options, to avoid having to continue to add more arguments to the pushThreadBindings calls done in several places.

Comment by Ghadi Shayban [ 29/Oct/12 10:36 AM ]

Thanks, Andy.

Alternately for the last ns patch, it is equivalent to call (print-method msg err), rather than binding out to err, may be more readable. I'll be glad to send that in if it's preferable.

Comment by Andy Fingerhut [ 13/Feb/13 12:38 AM ]

706-deprecated-var-warning-patch-v2.txt dated Feb 12 2013 is identical to 706-deprecated-var-warning.diff dated Oct 26 2012, except it applies cleanly to latest master.

Comment by Andy Fingerhut [ 23/Feb/15 8:21 PM ]

For the information of anyone examining this ticket wishing for this feature, the Eastwood lint tool reports calls to deprecated Clojure functions, and also to deprecated Java methods. https://github.com/jonase/eastwood

Comment by Alex Miller [ 25/Jan/16 12:32 PM ]

I'm interested in considering this for Clojure 1.9 but I need some help getting it ready. Some comments I have on the current state: - Ticket needs to have more details about the current approach

  • I prefer *warn-on-deprecated* over *warn-on-deprecation* because it echoes the keyword you use to mark deprecated vars
  • The warning message does not tell you a location, which is grr - should be similar to the reflection messages
  • Needs tests - see test/clojure/test_clojure/compilation.clj and test/clojure/test_helper.clj (should-not-reflect) for examples
  • clojure itself has some instances of deprecated usage - it would be nice to clean those up in the patch too. That may need to be in a separate patch, depends if they are easy to fix or not. If there are cases in test/ that are actually good to leave, can set *warn-on-deprecated* to false in that namespace.
  • Current default is true - should probably be false instead to match the reflection warning default.
Comment by Vijay Kiran [ 26/Jan/16 3:10 AM ]

Alex Miller I can give this a shot.

Comment by Alex Miller [ 26/Jan/16 8:51 AM ]

Hey Vijay, Andrew Rosa assigned it to himself so please coordinate with him as he was starting to work on it.

Comment by Bozhidar Batsov [ 26/Jan/16 10:52 AM ]

Just one small remark - isn't it more common to have deprecation warnings enabled by default? One could argue they are way more important than reflection warnings, as your code might get broken in the future because you didn't notice you were using deprecated stuff.

Comment by Alex Miller [ 26/Jan/16 2:01 PM ]

Bozhidar Batsov I'm on the fence. My main hesitation in making it the default is that people will suddenly have a bunch of new warnings (which could be either good or bad I suppose). Depends how strongly we want people to care about deprecations I guess.

Comment by Phill Wolf [ 26/Jan/16 9:33 PM ]

A deprecation warning that is off by default does not address the first and primary problem given in this ticket: "It is easy to use deprecated namespaces without knowing you are doing so."

It's unlike the reflection warning. You may focus on speed at any time, at your leisure. But the eventual removal of at-risk features will be a sudden, unpleasant surprise; a warning would be helpful.

But - Suppose I wrote 300 lines of Clojure and use a million lines that come from jars. Will any deprecation problems in my own code be buried in a tsunami of warnings about those jars? Worse, the tsunami will likely linger for weeks or months, until the libraries' respective authors catch up. Inasmuch as the jars are covered (much more expediently) by 'lein ancient' and similar, I would prefer to be able to limit deprecation warnings to just my stuff, perhaps by namespace prefix if from-a-jar-or-not is inconvenient from the compiler's point of view.

Comment by Alex Miller [ 26/Jan/16 10:35 PM ]

There is a middle ground here to turn it off by default in the compiler, but to turn it on by default in the tools (like lein). But there's a reasonable chance that whatever I prefer, Rich will have a preference that overrules it when it gets to him.

I think creating more complexity around namespace prefixes is unlikely to help this ticket move forward.

Comment by Cezary Kosko [ 07/Mar/16 9:18 PM ]

Uploaded a patch that coalesces var/ns-related patches by Luke & adds tests.
The patch does not, however, warn the user about deprecated macros, I assume I should adjust it, then?

Also, I'm not able adjust the description, so how do I take care of Alex's list's first bullet?

Comment by Andy Fingerhut [ 08/Mar/16 1:05 AM ]

Cezary, I have bumped up your permissions on JIRA so you should be able to edit tickets now. Please reload the page and try again.

Comment by Alex Miller [ 10/Mar/16 10:54 AM ]
  • The if in the first change in core.clj should be a when instead.
  • Can namespace deprecation warning include more about where this is occurring?
  • I'm having a hard time reproducing the deprecated ns warning in a manual test (see below). There seems to be something weird about the binding+printf as the conditions appear to be satisfied. I'm thinking it has something to do with flushing *err*? Seems like (println "Warning: loading deprecated ns" lib) would be better there.
(set! *warn-on-deprecated* true)
(ns foo {:deprecated true})
(ns bar (:require foo))
  • src/jvm/clojure/lang/Compile.java needs added support for clojure.compile.warn-on-deprecated RT flag
  • I think we should turn on warn-on-deprecated in the Clojure build itself (in build.xml)
  • If you do that, the following deprecation warnings exist in the Clojure build itself and we should fix those:

[java] Deprecation warning, clojure/core_proxy.clj:112:75 : var #'clojure.core/replicate is tagged as deprecated
[java] Deprecation warning, clojure/genclass.clj:149:41 : var #'clojure.core/replicate is tagged as deprecated
[java] Deprecation warning, clojure/genclass.clj:235:65 : var #'clojure.core/replicate is tagged as deprecated
[java] Deprecation warning, clojure/test/junit.clj:118:22 : var #'clojure.test/file-position is tagged as deprecated

  • Mark clojure.parallel as deprecated in the ns meta
Comment by Cezary Kosko [ 11/Mar/16 5:40 AM ]

Uploaded a new diff addressing the comments & added warning on macroexpansion.

As far as the namespace deprecation warning goes, though, the code's only printing the current namespace, did not know whether there was a decent way to get a file/line combo.

Comment by Alex Miller [ 11/Mar/16 8:53 AM ]

One more (hopefully final) round and then I think we're good:

  • The docstring for warn-on-deprecated should be updated now that we've expanded scope to cover ns too.
  • In the deprecated ns warning message, can we make it: "Deprecation warning: loading deprecated namespace `foo` from namespace `bar`."
  • In the macro and var warnings can we change "is tagged as deprecated" to just "is deprecated"?
  • Clean up the hanging parens in test/clojure/test_clojure/compilation/deprecated.clj

Thanks for the work on this!!

Comment by Alex Miller [ 11/Mar/16 1:49 PM ]

Marking pre-screened for Rich to look at.

Comment by Simon Gray [ 20/Sep/18 4:32 AM ]

What happened to this feature? Is it still coming?





[CLJ-1289] aset-* and aget perform poorly on multi-dimensional arrays even with type hints. Created: 01/Nov/13  Updated: 17/Sep/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Enhancement Priority: Critical
Reporter: Michael O. Church Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: arrays, performance
Environment:

Clojure 1.5.1.

Dependencies: criterium


Attachments: Text File CLJ-1289-p1.patch     Text File CLJ-1289-p2.patch     Text File CLJ-1289-p2-repl.txt    
Patch: Code
Approval: Triaged

 Description   

Here's a transcript of the behavior. I don't know for sure that reflection is being done, but the performance penalty (about 1300x) suggests it.

user=> (use 'criterium.core)
nil
user=> (def b (make-array Double/TYPE 1000 1000))
#'user/b
user=> (quick-bench (aget ^"[[D" b 304 175))
WARNING: Final GC required 3.5198021166354323 % of runtime
WARNING: Final GC required 29.172288684474303 % of runtime
Evaluation count : 63558 in 6 samples of 10593 calls.
             Execution time mean : 9.457308 µs
    Execution time std-deviation : 126.220954 ns
   Execution time lower quantile : 9.344450 µs ( 2.5%)
   Execution time upper quantile : 9.629202 µs (97.5%)
                   Overhead used : 2.477107 ns

One workaround is to use multiple agets.

user=> (quick-bench (aget ^"[D" (aget ^"[[D" b 304) 175))
WARNING: Final GC required 40.59820310542545 % of runtime
Evaluation count : 62135436 in 6 samples of 10355906 calls.
             Execution time mean : 6.999273 ns
    Execution time std-deviation : 0.112703 ns
   Execution time lower quantile : 6.817782 ns ( 2.5%)
   Execution time upper quantile : 7.113845 ns (97.5%)
                   Overhead used : 2.477107 ns

Cause: The inlined version only applies to arity 2, and otherwise it reflects.



 Comments   
Comment by Gary Fredericks [ 08/Dec/13 9:28 PM ]

A glance at the source makes it obvious that the hypothesis is correct – the inlined version only applies to arity 2, and otherwise it reflects.

I thought this would be as simple as converting the inline function to be variadic (using reduce), but after trying it I realized this is tricky as you have to generate the correct type hints for each step. E.g., given ^"[[D" the inline function needs to type-hint the intermediate result with ^"[D". This isn't difficult if we're just dealing with strings that begin with square brackets, but I don't know for sure that those are the only possibilities.

Comment by Yaron Peleg [ 13/Feb/14 4:44 AM ]

Bump. I just got bitten bad by this.

There are two seperate issues here:
1) (aget 2d-array-doubles 0 0 ) doesn't emit a reflection warning.
2) It seems like the compiler has enough information to avoid the reflective call here.

Note this gets exp. worse as number of dimensions grows, i.e (get doubles3d 0 0 0)
will be 1M slower, etc' Not true, unless you iterate over all elements. it's
simply n_dims*1000x per lookup.

Nasty surprise, especially considering you often go to primitive arrays for speed,
and a common use case is an inner loop(s) that iterate over arrays.

Comment by Gary Fredericks [ 13/Feb/14 7:08 AM ]

I can probably take a stab at this.

Comment by Gary Fredericks [ 13/Feb/14 8:34 PM ]

I think the reflection warning problem is pretty much impossible to solve without changing code elsewhere in the compiler, because the reflection done in aget is a different kind than normal clojure reflection – it's explicitly in the function body rather than emitted by the compiler. Since the compiler isn't emitting it, it doesn't reasonably know it's even there. So even if aget is fixed for other arities, you still won't get the warning when it's not inlined.

I can imagine some sort of metadata that you could put on a function telling the compiler that it will reflect if not inlined. Or maybe a more generic not-inlined warning?

The global scope of adding another compiler flag seems about balanced by the seriousness of array functions not being able to warn on reflection.

Comment by Gary Fredericks [ 13/Feb/14 8:52 PM ]

Attached CLJ-1289-p1.patch which simply inlines variadic calls to aget. It assumes that if it sees a :tag on the array arg that is a string beginning with [, it can assume that the return value from one call to aget can be tagged with the same string with the leading [ stripped off.

I'm not a jvm expert, but having read through the spec a little bit I think this is a reasonable assumption.

Comment by Alex Miller [ 14/Feb/14 3:34 PM ]

I think this probably is actually true, but a more official way to ask that question would be to get the array class and ask for Class.getComponentType() (and less janky than string munging).

Comment by Gary Fredericks [ 14/Feb/14 3:40 PM ]

How would you get the array class based on the :tag type hint?

Comment by Gary Fredericks [ 14/Feb/14 7:05 PM ]

I see (-> s (Class/forName) (.getComponentType) (.getName)) does the same thing – is that route preferred, or is there another one?

Comment by Alexander Yakushev [ 02/Sep/18 11:26 AM ]

I've taken a stab at the implementation suggested by Alex Miller. The attached patch uses getComponentType instead of string magic, and introduces the following improvements compared to the first patch:

  • aset is now supported as well. All indices but last are unrolled into RT.aget calls and the outermost call is expanded to RT.aset.
  • If the inlined version can't resolve the type of the array at any point, then, instead of unrolling into N RT.aget calls (which will cause N compiler reflection sites) it will generate an invocation of the non-inlined aget call that will use Array.get (which is faster).

On the downside, multi-arity calls to aset now trigger compiler reflection where it used to be Array.set. I wonder if it makes sense to smoothen out those corners too, or whether it's actually better that reflection in such cases is more visible (shows in compiler warnings).

I also attached the REPL log of validation examples (uses clj-java-decompiler). It would be nice to convert it into tests, but I don't yet know how.

On a side note, I had to use a hack ((var aget) ...) to force the non-inlined version to be called. Can't say I like it much, but I haven't come up with anything better. Another way would be to separate non-inlined version into a separate private function, but I don't want to add even more Vars to core namespace.

Comment by Alexander Yakushev [ 02/Sep/18 11:31 AM ]

Patch reuploaded: minor fix.

Comment by Alexander Yakushev [ 04/Sep/18 8:59 AM ]

BTW, why does the docstring for aset says it works only on arrays of reference types? Is this comment outdated? We can fix it it along the way.

Comment by Alexander Yakushev [ 15/Sep/18 2:53 AM ]

Is there a chance to review this for 1.10? Perhaps, the implementation is too complicated and needs more time to consider? I might try to reduce the scope then.

Comment by Alex Miller [ 17/Sep/18 8:33 AM ]

It's complicated, not sure if its worth this or not. Probably won't look at it for 1.10.

Comment by Alexander Yakushev [ 17/Sep/18 8:49 AM ]

Thanks for the answer. In terms of complexity, I can remove the part that "optimizes" reflective calls, which both simplifies the algorithm and makes the reflection sites visible to the compiler (and thus to the user).





[CLJ-440] java method calls cannot omit varargs Created: 27/Sep/10  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Critical
Reporter: Alexander Taggart Assignee: Ragnar Dahlen
Resolution: Unresolved Votes: 20
Labels: interop

Attachments: Text File 0001-CLJ-440-Allow-calling-vararg-Java-methods-without-va.patch    
Approval: Triaged

 Description   

Problem

Clojure calls to Java vararg methods require creating an object array for the final arg. This is a frequent source of confusion when doing interop.

E.g., trying to call java.util.Collections.addAll(Collection c, T... elements):

user=> (Collections/addAll [] (object-array 0))
false
user=> (Collections/addAll [])
IllegalArgumentException No matching method: addAll  clojure.lang.Compiler$StaticMethodExpr.<init> (Compiler.java:1401)

The Method class provides an isVarArg() method, which could be used to inform the compiler to process things differently.

From http://groups.google.com/group/clojure/browse_thread/thread/7d0d6cb32656a621

Latest patch: Removed because incomplete and goal not clear

Varargs in Java

As currently stated, the scope of this ticket is only to omit varargs, but this is only one case where Clojures handling of varargs differs from Java. For completeness, here is a brief survey of how Java handles vararg methods, which could hopefully inform a discussion for how Clojure could do things differently, and what the goal of this ticket should be.

Given the following setup:

VarArgs.java
public class VarArgs {

    public static class SingleVarargMethod {
        public static void m(String arg1, String... args) {}
    }

    public static class MultipleVarargMethods {
        public static void m(String... args) {}
        public static void m(String arg1) {}
        public static void m(String arg1, String... args) {}
    }
}
Java Possible clojure equivalent? Comments
VarArgs.SingleVarargMethod.m("a"); (SingleVarargMethod/m "a")  
VarArgs.SingleVarargMethod.m("a", "b"); (SingleVarargMethod/m "a" "b")  
VarArgs.SingleVarargMethod.m("a", "b", "c"); (SingleVarargMethod/m "a" "b" "c")  
VarArgs.SingleVarargMethod.m("a", new String[]{"b", "c"}); (SingleVarargMethod/m "a" (object-array ["b" "c"]))  
VarArgs.MultipleVarargMethods.m(); (MultipleVarargMethods/m)  
VarArgs.MultipleVarargMethods.m((String) null); (MultipleVarargMethods/m nil) Use type hints to disambiguate?
VarArgs.MultipleVarargMethods.m((String[]) null); (MultipleVarargMethods/m nil) Use type hints to disambiguate?
VarArgs.MultipleVarargMethods.m("a", null); (MultipleVarargMethods/m "a" nil)  
VarArgs.MultipleVarargMethods.m("a", new String[]{}); (MultipleVarargMethods/m "a" (object-array 0))  
VarArgs.MultipleVarargMethods.m(new String[]{"a"}); (MultipleVarargMethods/m (object-array ["a"]))  
VarArgs.MultipleVarargMethods.m("a", new String[]{"b", "c"}); (MultipleVarargMethods/m "a" (object-array ["b" "c"]))  


 Comments   
Comment by Assembla Importer [ 27/Sep/10 8:19 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/440

Comment by Alexander Taggart [ 01/Apr/11 11:16 PM ]

Patch adds support for varargs. Builds on top of patch in CLJ-445.

Comment by Alexander Taggart [ 05/Apr/11 5:45 PM ]

Patch updated to current CLJ-445 patch.

Comment by Nick Klauer [ 29/Oct/12 8:12 AM ]

Is this ticket on hold? I find myself typing (.someCall arg1 arg2 (into-array SomeType nil)) alot just to get the right method to be called. This ticket sounds like it would address that extraneous into-array arg that I use alot.

Comment by Andy Fingerhut [ 29/Oct/12 10:45 AM ]

fixbug445.diff uploaded on Oct 29 2012 was written Oct 23 2010 by Alexander Taggart. I am simply copying it from the old Assembla ticket tracking system to here to make it more easily accessible. Not surprisingy, it doesn't apply cleanly to latest master. I don't know how much effort it would be to update it, but only a few hunks do not apply cleanly according to 'patch'. See the "Updating stale patches" section on the JIRA workflow page here: http://dev.clojure.org/display/design/JIRA+workflow

Comment by Andy Fingerhut [ 29/Oct/12 10:56 AM ]

Ugh. Deleted the attachment because it was for CLJ-445, or at least it was named that way. CLJ-445 definitely has a long comment history, so if one or more of its patches address this issue, then you can read the discussion there to see the history.

I don't know of any "on hold" status for tickets, except for one or two where Rich Hickey has explicitly said in a comment that he wants to wait a while before making the change. There are just tickets that contributors choose to work on and ones that screeners choose to screen.

Comment by Alex Miller [ 02/Feb/16 11:47 AM ]

I would love to see an updated patch on this ticket that specifically addressed the varargs issue without building on the other mentioned ticket and patch (which is of lower priority).

Comment by Ragnar Dahlen [ 03/Feb/16 8:01 AM ]

I had a stab at this, have attached an initial patch, parts of which I'm not too sure/happy about so feedback would be appreciated.

The patch takes the following approach:

  1. Teach Reflector/getMethods how to find matching vararg methods. In addition to the current constraints, a method can also match if it is a varargs method, and the arity of the method is one more than the requested arity. That means it's a varargs method we could call, but the user hasn't provided the varargs argument.
  2. In MethodExpr/emitTypedArgs we handle the case were there is one more argument in the method being called than there were arguments provided. The only case were that should happen is when it is a varargs method and the last argument was not provided. In that case we push a new empty object array to the stack.

I'm not to sure about my implementation of the second part. It could open up for some hard to understand bugs in the future. One option would be to be more defensive, and make sure it's really the last argument for instance, or even pass along the Method object (or a varargs flag) so we know what we can expect and need to do.

Comment by Ragnar Dahlen [ 03/Feb/16 8:49 AM ]

I realised my patch is missing two important cases; the interface handling in Reflector and handling multiple matching methods. I'll look into that too, but would still appreciate feedback on the approach in MethodExpr/emitTypedArgs.

Comment by Alex Miller [ 03/Feb/16 9:00 AM ]

I am in favor of using isVarArg() to explicitly handle this case rather than guessing if we're in this situation. We should check the behavior (and add tests where it seems needed) for calling a var args method with too few args, too many args, etc. And also double-check that non vararg cases have not changed behavior.

Also, keep in mind that as a general rule, existing AOT compiled code may rely on calling into public Reflector methods, so if you change the signatures of public Reflector methods, you should leave a version with the old arity that has some default behavior for backwards compatibility.

Comment by Ghadi Shayban [ 21/Apr/17 11:31 AM ]

Any extra logic that the compiler implements will need to distinguish between:

public static class MultipleVarargMethods {
        public static void m(String... args) {}
        public static void m(String arg1, String... args) {}
    }

which I don't think is possible generically, without breaking code.

Rather than omitting varargs, how about handling them without tedious array construction. An alternative is to introduce new explicit sugar that you have to opt-in to:

(Whatever/varargs a b c ... x y z)

where ... or similar would be understood by StaticMethodExpr or InstanceMethodExpr in the compiler, and could be type-hinted to resolve ambiguity. This would not be a breaking change.

Comment by Phill Wolf [ 27/Apr/17 6:58 PM ]

If javac can tell the methods apart without the caller providing a "..." partition, so should Clojure. (But in the specific "MultipleVarargMethods" class, javac can't distinguish:

public class MultipleVarargMethods {
    public static void m(String... args) {}
    public static void m(String arg1, String... args) {}
    public static void main(String [] args) {
        m("bankruptcy");
        m("bankruptcy","in","progress");
    }
}


MultipleVarargMethods.java:5: error: reference to m is ambiguous
        m("bankruptcy");
        ^
  both method m(String...) in MultipleVarargMethods and method m(String,String...) in MultipleVarargMethods match
MultipleVarargMethods.java:6: error: reference to m is ambiguous
        m("bankruptcy","in","progress");
        ^
  both method m(String...) in MultipleVarargMethods and method m(String,String...) in MultipleVarargMethods match
2 errors

)





[CLJ-1814] Make `satisfies?` as fast as a protocol method call Created: 11/Sep/15  Updated: 20/Nov/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Critical
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 14
Labels: performance, protocols

Attachments: Text File 0001-CLJ-1814-cache-protocol-impl-satisfies-as-fast-as-me.patch     Text File 0001-CLJ-1814-cache-protocol-impl-satisfies-as-fast-as-me-v2.patch     Text File 0001-CLJ-1814-cache-protocol-impl-satisfies-as-fast-as-me-v3.patch     Text File 0001-CLJ-1814-cache-protocol-impl-satisfies-as-fast-as-me-v4.patch     Text File 0001-CLJ-1814-cache-protocol-impl-satisfies-as-fast-as-me-v5.patch     Text File CLJ-1814-v6.patch     Text File CLJ-1814-v7.patch    
Patch: Code and Test
Approval: Vetted

 Description   

Currently `satisfies?` doesn't use the same impl cache used by protocol methods, making it too slow for real world usage.

With:

(defprotocol p (f [_]))
(deftype x [])
(deftype y [])
(extend-type x p (f [_]))

Before patch:

(let [s "abc"] (bench (instance? CharSequence s))) ;; Execution time mean : 1.358360 ns
(let [x (x.)] (bench (satisfies? p x))) ;; Execution time mean : 112.649568 ns
(let [y (y.)] (bench (satisfies? p y))) ;; Execution time mean : 2.605426 µs

Cause: `satisfies?` calls `find-protocol-impl` to see whether an object implements a protocol, which checks for whether x is an instance of the protocol interface or whether x's class is one of the protocol implementations (or if its in an inheritance chain that would make this true). This check is fairly expensive and not cached.

Proposed: Extend the protocol's method impl cache to also handle (and cache) instance checks (including negative results).

After patch:

(let [x (x.)] (bench (satisfies? p x))) ;; Execution time mean : 79.321426 ns
(let [y (y.)] (bench (satisfies? p y))) ;; Execution time mean : 77.410858 ns

Patch: CLJ-1814-v7.patch (depends on CLJ-2426)



 Comments   
Comment by Michael Blume [ 11/Sep/15 4:17 PM ]

Nice. Honeysql used to spend 80-90% of its time in satisfies? calls before we refactored them out.

Comment by Michael Blume [ 24/Sep/15 3:55 PM ]

I realize this is a deeply annoying bug to reproduce, but if I clone core.match, point its Clojure dependency to 1.8.0-master-SNAPSHOT, start a REPL, connect to the REPL from vim, and reload clojure.core.match, I get

|| java.lang.Exception: namespace 'clojure.tools.analyzer.jvm.utils' not found, compiling:(clojure/tools/analyzer/jvm.clj:9:1)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5647| clojure.core$throw_if.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5733| clojure.core$load_lib.invokeStatic
|| clojure.core$load_lib.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:142)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5765| clojure.core$load_libs.invokeStatic
|| clojure.core$load_libs.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:137)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5787| clojure.core$require.invokeStatic
|| clojure.core$require.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:703)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.analyzer.jvm/0.6.5/tools.analyzer.jvm-0.6.5.jar::clojure/tools/analyzer/jvm.clj|9| clojure.tools.analyzer.jvm$eval4968$loading__5561__auto____4969.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.analyzer.jvm/0.6.5/tools.analyzer.jvm-0.6.5.jar::clojure/tools/analyzer/jvm.clj|9| clojure.tools.analyzer.jvm$eval4968.invokeStatic
|| clojure.tools.analyzer.jvm$eval4968.invoke(jvm.clj)
|| clojure.lang.Compiler.eval(Compiler.java:6934)
|| clojure.lang.Compiler.eval(Compiler.java:6923)
|| clojure.lang.Compiler.load(Compiler.java:7381)
|| clojure.lang.RT.loadResourceScript(RT.java:372)
|| clojure.lang.RT.loadResourceScript(RT.java:363)
|| clojure.lang.RT.load(RT.java:453)
|| clojure.lang.RT.load(RT.java:419)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5883| clojure.core$load$fn__5669.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5882| clojure.core$load.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5683| clojure.core$load_one.invokeStatic
|| clojure.core$load_one.invoke(core.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5728| clojure.core$load_lib$fn__5618.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5727| clojure.core$load_lib.invokeStatic
|| clojure.core$load_lib.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:142)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5765| clojure.core$load_libs.invokeStatic
|| clojure.core$load_libs.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:137)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5787| clojure.core$require.invokeStatic
|| clojure.core$require.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:457)
src/main/clojure/clojure/core/match.clj|1| clojure.core.match$eval4960$loading__5561__auto____4961.invoke
src/main/clojure/clojure/core/match.clj|1| clojure.core.match$eval4960.invokeStatic
|| clojure.core.match$eval4960.invoke(match.clj)
|| clojure.lang.Compiler.eval(Compiler.java:6934)
|| clojure.lang.Compiler.eval(Compiler.java:6923)
|| clojure.lang.Compiler.load(Compiler.java:7381)
|| clojure.lang.RT.loadResourceScript(RT.java:372)
|| clojure.lang.RT.loadResourceScript(RT.java:363)
|| clojure.lang.RT.load(RT.java:453)
|| clojure.lang.RT.load(RT.java:419)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5883| clojure.core$load$fn__5669.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5882| clojure.core$load.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5683| clojure.core$load_one.invokeStatic
|| clojure.core$load_one.invoke(core.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5728| clojure.core$load_lib$fn__5618.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5727| clojure.core$load_lib.invokeStatic
|| clojure.core$load_lib.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:142)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5765| clojure.core$load_libs.invokeStatic
|| clojure.core$load_libs.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:137)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5787| clojure.core$require.invokeStatic
|| clojure.core$require.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:421)
|| clojure.core.match$eval4949.invokeStatic(form-init2494799382238714928.clj:1)
|| clojure.core.match$eval4949.invoke(form-init2494799382238714928.clj)
|| clojure.lang.Compiler.eval(Compiler.java:6934)
|| clojure.lang.Compiler.eval(Compiler.java:6897)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|3096| clojure.core$eval.invokeStatic
|| clojure.core$eval.invoke(core.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|240| clojure.main$repl$read_eval_print__7404$fn__7407.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|240| clojure.main$repl$read_eval_print__7404.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|258| clojure.main$repl$fn__7413.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|258| clojure.main$repl.invokeStatic
|| clojure.main$repl.doInvoke(main.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:1523)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|58| clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__637.invoke
|| clojure.lang.AFn.applyToHelper(AFn.java:152)
|| clojure.lang.AFn.applyTo(AFn.java:144)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|645| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|1874| clojure.core$with_bindings_STAR_.invokeStatic
|| clojure.core$with_bindings_STAR_.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:425)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|56| clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invokeStatic
|| clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invoke(interruptible_eval.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|191| clojure.tools.nrepl.middleware.interruptible_eval$interruptible_eval$fn__679$fn__682.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|159| clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__674.invoke
|| clojure.lang.AFn.run(AFn.java:22)
|| java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
|| java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
|| java.lang.Thread.run(Thread.java:745)

Same thing with reloading a namespace in my own project which depends on clojure.core.match

Comment by Nicola Mometto [ 24/Sep/15 3:59 PM ]

is it possible that AOT is involved?

Comment by Michael Blume [ 24/Sep/15 5:31 PM ]

Narrowed it down a little, if I check out tools.analyzer.jvm, open a REPL, and do (require 'clojure.tools.analyzer.jvm.utils) I get

|| java.lang.ClassCastException: java.lang.Class cannot be cast to clojure.asm.Type, compiling:(utils.clj:260:13)
|| clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3642)
|| clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3636)
|| clojure.lang.Compiler$DefExpr.eval(Compiler.java:450)
|| clojure.lang.Compiler.eval(Compiler.java:6939)
|| clojure.lang.Compiler.load(Compiler.java:7381)
|| clojure.lang.RT.loadResourceScript(RT.java:372)
|| clojure.lang.RT.loadResourceScript(RT.java:363)
|| clojure.lang.RT.load(RT.java:453)
|| clojure.lang.RT.load(RT.java:419)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5883| clojure.core$load$fn__5669.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5882| clojure.core$load.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5683| clojure.core$load_one.invokeStatic
|| clojure.core$load_one.invoke(core.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5728| clojure.core$load_lib$fn__5618.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5727| clojure.core$load_lib.invokeStatic
|| clojure.core$load_lib.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:142)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5765| clojure.core$load_libs.invokeStatic
|| clojure.core$load_libs.doInvoke(core.clj)
|| clojure.lang.RestFn.applyTo(RestFn.java:137)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|647| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|5787| clojure.core$require.invokeStatic
|| clojure.core$require.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:421)
|| clojure.tools.analyzer.jvm.utils$eval4392.invokeStatic(form-init8663423518975891793.clj:1)
|| clojure.tools.analyzer.jvm.utils$eval4392.invoke(form-init8663423518975891793.clj)
|| clojure.lang.Compiler.eval(Compiler.java:6934)
|| clojure.lang.Compiler.eval(Compiler.java:6897)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|3096| clojure.core$eval.invokeStatic
|| clojure.core$eval.invoke(core.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|240| clojure.main$repl$read_eval_print__7404$fn__7407.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|240| clojure.main$repl$read_eval_print__7404.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|258| clojure.main$repl$fn__7413.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/main.clj|258| clojure.main$repl.invokeStatic
|| clojure.main$repl.doInvoke(main.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:1523)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|58| clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__637.invoke
|| clojure.lang.AFn.applyToHelper(AFn.java:152)
|| clojure.lang.AFn.applyTo(AFn.java:144)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|645| clojure.core$apply.invokeStatic
zipfile:/Users/michael.blume/.m2/repository/org/clojure/clojure/1.8.0-master-SNAPSHOT/clojure-1.8.0-master-SNAPSHOT.jar::clojure/core.clj|1874| clojure.core$with_bindings_STAR_.invokeStatic
|| clojure.core$with_bindings_STAR_.doInvoke(core.clj)
|| clojure.lang.RestFn.invoke(RestFn.java:425)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|56| clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invokeStatic
|| clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invoke(interruptible_eval.clj)
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|191| clojure.tools.nrepl.middleware.interruptible_eval$interruptible_eval$fn__679$fn__682.invoke
zipfile:/Users/michael.blume/.m2/repository/org/clojure/tools.nrepl/0.2.10/tools.nrepl-0.2.10.jar::clojure/tools/nrepl/middleware/interruptible_eval.clj|159| clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__674.invoke
|| clojure.lang.AFn.run(AFn.java:22)
|| java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
|| java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
|| java.lang.Thread.run(Thread.java:745)

I don't see where AOT would be involved?

Comment by Nicola Mometto [ 27/Sep/15 2:28 PM ]

Michael Blume The updated patch should fix the issue you reported

Comment by Michael Blume [ 28/Sep/15 12:39 PM ]

Cool, thanks =)

New patch no longer deletes MethodImplCache, which is not used – is that deliberate?

Comment by Alex Miller [ 02/Nov/15 3:08 PM ]

It would be cool if there was a bulleted list of the things changed in the patch in the description. For example: "Renamed MethodImplCache to ImplCache", etc. That helps makes it easier to review.

Comment by Nicola Mometto [ 02/Nov/15 3:35 PM ]

Attached is an updated patch that doesn't replace MethodImplCache with ImplCache but simply reuses MethodImplCache, reducing the impact of this patch and making it easier (and safer) to review.

Comment by Alex Miller [ 07/Jun/16 11:42 AM ]

Bumping priority as this is used in new inst? predicate - see https://github.com/clojure/clojure/commit/58227c5de080110cb2ce5bc9f987d995a911b13e

Comment by Alex Miller [ 29/Jun/17 2:31 PM ]

I ran the before and after tests with the v3 patch. Before times matched pretty closely but I could not replicate the after results. I got this which is actually much worse in the not found case:

(let [x (x.)] (bench (satisfies? p x))) ;; Execution time mean : 76.833504 ns
(let [y (y.)] (bench (satisfies? p y))) ;; Execution time mean : 20.570007 µs
Comment by Nicola Mometto [ 29/Jun/17 4:09 PM ]

v4 patch fixes the regression on the not-found case, not sure how that happened, apologies.
Here are the timings I'm getting now:

clojure master:

user=> (let [x (x.)] (bench (satisfies? p x)))
Evaluation count : 604961580 in 60 samples of 10082693 calls.
             Execution time mean : 112.649568 ns
    Execution time std-deviation : 12.216782 ns
   Execution time lower quantile : 99.299203 ns ( 2.5%)
   Execution time upper quantile : 144.265205 ns (97.5%)
                   Overhead used : 1.898271 ns

Found 3 outliers in 60 samples (5.0000 %)
	low-severe	 2 (3.3333 %)
	low-mild	 1 (1.6667 %)
 Variance from outliers : 73.7545 % Variance is severely inflated by outliers
nil
user=> (let [y (y.)] (bench (satisfies? p y)))
Evaluation count : 22676100 in 60 samples of 377935 calls.
             Execution time mean : 2.605426 µs
    Execution time std-deviation : 141.100070 ns
   Execution time lower quantile : 2.487234 µs ( 2.5%)
   Execution time upper quantile : 2.873045 µs (97.5%)
                   Overhead used : 1.898271 ns

Found 1 outliers in 60 samples (1.6667 %)
	low-severe	 1 (1.6667 %)
 Variance from outliers : 40.1251 % Variance is moderately inflated by outliers
nil

master + v4:

user=> (let [x (x.)] (bench (satisfies? p x)))
Evaluation count : 731759100 in 60 samples of 12195985 calls.
             Execution time mean : 79.321426 ns
    Execution time std-deviation : 3.959245 ns
   Execution time lower quantile : 75.365187 ns ( 2.5%)
   Execution time upper quantile : 87.986479 ns (97.5%)
                   Overhead used : 1.905711 ns

Found 1 outliers in 60 samples (1.6667 %)
	low-severe	 1 (1.6667 %)
 Variance from outliers : 35.2614 % Variance is moderately inflated by outliers
nil
user=> (let [y (y.)] (bench (satisfies? p y)))
Evaluation count : 771220140 in 60 samples of 12853669 calls.
             Execution time mean : 77.410858 ns
    Execution time std-deviation : 1.407926 ns
   Execution time lower quantile : 75.852530 ns ( 2.5%)
   Execution time upper quantile : 80.759226 ns (97.5%)
                   Overhead used : 1.897646 ns

Found 4 outliers in 60 samples (6.6667 %)
	low-severe	 3 (5.0000 %)
	low-mild	 1 (1.6667 %)
 Variance from outliers : 7.7866 % Variance is slightly inflated by outliers

So to summarize:
master found = 112ns
master not-found = 2.6us

master+v4 found = 79ns
master+v4 not-found = 77ns

Comment by Michael Blume [ 14/Jul/17 5:12 PM ]

For records that have been declared with an implementation of a particular protocol, and which therefore implement the corresponding interface, would it make sense to use an (instance?) check against that interface as a fast path?

Comment by Alex Miller [ 04/Aug/17 11:28 AM ]

Michael - that check is already in there

Nicola - I have a few comments/questions:

1. I don't get what the purpose of the NIL stuff is - could you explain that?
2. In the case where x is an instance of the interface, the old code returned x and the new code in find-protocol-impl* returns interface. Why the change?
3. This: (alter-var-root (:var protocol) assoc :impl-cache (expand-method-impl-cache cache c impl)) is not thread-safe afaict - I think simultaneous misses in two different threads for different impls would cause the cache to only have one of them. This is probably unlikely, and probably not a big deal since the cache will just be updated on the next call (not give a wrong answer), but wanted to mention it. I don't see any easy way to avoid it without a lot of changes.

Comment by Nicola Mometto [ 04/Aug/17 6:14 PM ]

Alex, thanks for looking at this,
1- The NIL object is a placeholder in the method impl cache for nil, as `find-and-cache-protocol-impl` tests for `nil?` to know if the dispatch has been cached or not

2- The change is purely a consistency one, making find-and-cache-protocol-impl always return a class/interface rather than either a class/interface or a concrete instance. Behaviourally, it doesn't change anything since the two consumers of `find-protocol-impl`, namely `find-protocol-method` and `satisfies?` don't care what that value is in that case

3- Yes you are correct that it is not thread safe, however I think it's a decent tradeoff as it doesn't cause any incorrect behaviour and at worse would cause an extra cache miss, making it thread safe would mean an extra performance penalty in every cache hit/miss

Comment by Michael Blume [ 16/Aug/17 1:44 PM ]

Nicola Mometto I'm seeing a change in behavior from this patch

(defprotocol BoolProtocol
  (proto-fn [this]))

(extend-protocol BoolProtocol
  Object
  (proto-fn [x] "Object impl")

  nil
  (proto-fn [x] "Nil impl"))

(proto-fn false)

returns "Object impl" with Clojure master and "Nil impl" with this patch

Comment by Nicola Mometto [ 17/Aug/17 3:08 AM ]

That's not good, I'll take a look later today, thanks

Comment by Nicola Mometto [ 18/Aug/17 3:29 AM ]

This was an issue with how `nil` was cached, I decided to special-case `nil` to skip the method cache, removing the need for all the `NIL` funny business and fixing this bad interaction between `false` and `nil`.

Comment by Michael Blume [ 18/Aug/17 1:17 PM ]

Not sure if it's in scope for this ticket, but given that this wasn't caught, there should probably be more protocol dispatch tests

Comment by Alex Miller [ 20/Aug/17 5:00 PM ]

yes, should definitely add

Comment by Michael Blume [ 21/Aug/17 12:52 PM ]

Patch with test

Comment by Michael Blume [ 21/Aug/17 12:56 PM ]

Verified that test fails with v4 patch:

[java] Testing clojure.test-clojure.protocols
     [java]
     [java] FAIL in (test-default-dispatch) (protocols.clj:695)
     [java] expected: (= "Object impl" (test-dispatch false))
     [java]   actual: (not (= "Object impl" "Nil impl"))
     [java]
     [java] FAIL in (test-default-dispatch) (protocols.clj:695)
     [java] expected: (= "Object impl" (test-dispatch true))
     [java]   actual: (not (= "Object impl" "Nil impl"))
Comment by Michael Blume [ 18/Sep/17 2:19 PM ]

Has this patch missed the 1.9 train? There was a fix we were hoping to make in HoneySQL that I'd hesitate to make with satisfies? as slow as it is.

Comment by Alex Miller [ 18/Sep/17 2:48 PM ]

Not necessarily. We don't add features after 1.9 but perf stuff like this is still possible. It's been vetted by Rich. It's in my list of stuff to screen.

Comment by Nicola Mometto [ 20/Nov/18 7:16 AM ]

Updated patch to work after the new instance-based protocol dispatch, this ticket should wait for CLJ-2426 first





[CLJ-1872] empty? is broken for transient collections Created: 26/Dec/15  Updated: 08/Oct/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: Release 1.11

Type: Defect Priority: Critical
Reporter: Leonid Bogdanov Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: collections

Approval: Vetted

 Description   

Couldn't find whether it was brought up earlier, but it seems that empty? predicate is broken for transient collections

user=> (empty? (transient []))
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.PersistentVector$TransientVector  clojure.lang.RT.seqFrom (RT.java:528)

user=> (empty? (transient ()))
ClassCastException clojure.lang.PersistentList$EmptyList cannot be cast to clojure.lang.IEditableCollection  clojure.core/transient (core.clj:3209)

user=> (empty? (transient {}))
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.PersistentArrayMap$TransientArrayMap  clojure.lang.RT.seqFrom (RT.java:528)

user=> (empty? (transient #{}))
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.PersistentHashSet$TransientHashSet  clojure.lang.RT.seqFrom (RT.java:528)

The workaround is to use (zero? (count (transient ...))) check instead.



 Comments   
Comment by Alex Miller [ 26/Dec/15 9:58 PM ]

Probably similar to CLJ-700.





[CLJ-2413] Non-deterministic method selection during reflection Created: 04/Oct/18  Updated: 26/Nov/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Critical
Reporter: Ghadi Shayban Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: reflection

Attachments: Text File CLJ-2413-2.patch     Text File CLJ-2413.patch    
Patch: Code
Approval: Triaged

 Description   

Reflection does not return the same order of methods across JVM invocations (via Class::getMethods). This is probably most apparent when submitting Clojure functions, which are Callable and Runnable, into an executor:

(ns repro)

;;(set! *warn-on-reflection* true)

(defn repro
  []
  (let [exec (java.util.concurrent.ForkJoinPool/commonPool)
        work #(do 1)]
    (deref (.submit ^Object exec work))))  ;; intentionally reflect

(defn -main []
   ;; dereffing a runnable returns nil, a callable can return a value, in this case an integer
  (System/exit (or (repro) 0)))
nondeterministic ➜ while true; do clojure -m repro; echo $?; done
0
0
0
1
0
0
0
1
0
0
0


 Comments   
Comment by Ghadi Shayban [ 25/Nov/18 5:36 PM ]

attached a patch that sorts seen methods

Comment by Ghadi Shayban [ 26/Nov/18 8:51 AM ]

re patch: the comparator's first pass (examining the arity) can disappear: only identical arity methods get compared. Does that sound right?

Comment by Nicola Mometto [ 26/Nov/18 11:04 AM ]

Yeah, that sounds right to me

Comment by Ghadi Shayban [ 26/Nov/18 11:42 AM ]

patch with a more minimal comparator





[CLJ-1743] Avoid compile-time static initialization of classes when using inheritance Created: 02/Jun/15  Updated: 07/Sep/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6, Release 1.7
Fix Version/s: None

Type: Enhancement Priority: Critical
Reporter: Abe Fettig Assignee: Unassigned
Resolution: Unresolved Votes: 8
Labels: aot, compiler, interop

Attachments: Text File 0001-Avoid-compile-time-class-initialization-when-using-g.patch     Text File clj-1743-2.patch     Text File clj-1743-3.patch    
Patch: Code
Approval: Triaged

 Description   

I'm working on a project using Clojure and RoboVM. We use AOT compilation to compile Clojure to JVM classes, and then use RoboVM to compile the JVM classes to native code. In our Clojure code, we call Java APIs provided by RoboVM, which wrap the native iOS APIs.

But we've found an issue with inheritance and class-level static initialization code. Many iOS APIs require inheriting from a base object and then overriding certain methods. Currently, Clojure runs a superclass's static initialization code at compile time, whether using ":gen-class" or "proxy" to create the subclass. However, RoboVM's base "ObjCObject" class [1], which most iOS-specific classes inherit from, requires the iOS runtime to initialize, and throws an error at compile time since the code isn't running on a device.

CLJ-1315 addressed a similar issue by modifying "import" to load classes without running static initialization code. I've written my own patch which extends this behavior to work in ":gen-class" and "proxy" as well. The unit tests pass, and we're using this code successfully in our iOS app.

Patch: clj-1743-2.patch

Here's some sample code that can be used to demonstrate the current behavior (Full demo project at https://github.com/figly/clojure-static-initialization):

Demo.java
package clojure_static_initialization;

public class Demo {
  static {
    System.out.println("Running static initializers!");
  }
  public Demo () {
  }
}
gen_class_demo.clj
(ns clojure-static-initialization.gen-class-demo
  (:gen-class :extends clojure_static_initialization.Demo))
proxy_demo.clj
(ns clojure-static-initialization.proxy-demo)

(defn make-proxy []
  (proxy [clojure_static_initialization.Demo] []))

[1] https://github.com/robovm/robovm/blob/master/objc/src/main/java/org/robovm/objc/ObjCObject.java



 Comments   
Comment by Alex Miller [ 18/Jun/15 3:01 PM ]

No changes from previous, just updated to apply to master as of 1.7.0-RC2.

Comment by Alex Miller [ 18/Jun/15 3:03 PM ]

If you had a sketch to test this with proxy and gen-class, that would be helpful.

Comment by Abe Fettig [ 22/Jun/15 8:31 AM ]

Sure, what form would you like for the sketch code? A small standalone project? Unit tests?

Comment by Alex Miller [ 22/Jun/15 8:40 AM ]

Just a few lines of Java (a class with static initializer that printed) and Clojure code (for gen-class and proxy extending it) here in the test description that could be used to demonstrate the problem. Should not have any dependency on iOS or other external dependencies.

Comment by Abe Fettig [ 01/Jul/15 8:49 PM ]

Sample code added, let me know if I can add anything else!

Comment by Abe Fettig [ 27/Jul/15 2:21 PM ]

Just out of curiosity, what are the odds this could make it into 1.8?

Comment by Alex Miller [ 27/Jul/15 6:06 PM ]

unknown.

Comment by Didier A. [ 20/Nov/15 7:11 PM ]

I'm affected by this bug too. A function in a namespace calls a static Java variable which is initialized in place. Another namespace which is genclassed calls that function. Now at compile time, the static java is initialized and it makes building fail, because that static java initialization needs resources which don't exist on the build machine.

Comment by Michael Blume [ 13/Mar/17 10:00 PM ]

Refreshing patch so it applies to master, no changes, keeping attribution.

Comment by Alex Miller [ 27/Jun/17 5:22 PM ]

I am confused by the patch making changes in RT.loadClassForName() but the changes in Compiler are calls to RT.classForNameNonLoading()? Is this patch drift or what's up?

Comment by Michael Schwager [ 25/Sep/17 5:46 PM ]

Thank for you posting this patch. The issue with static initializers has been making it difficult to do JavaFX development with both AOT and interactive development. I cloned the Clojure 1.9.0-master source today and applied the patch, but the example Clojure project still shows "Running static initializers!" I verified this is the case with an actual use case of mine. The error goes away if I start a JFXPanel first. Is there a workaround as of Sept. 2017, eg another way of defining a proxy or deferring until runtime? Thank you.

$ lein clean;lein repl
Compiling 1 source files to C:\dev\clojure\clojure-static-initialization\target\classes
Compiling clojure-static-initialization.gen-class-demo
Compiling clojure-static-initialization.proxy-demo
Running static initializers!
Clojure 1.9.0-master-SNAPSHOT

user=> (def lcp (proxy [javafx.scene.control.ListCell] []))

CompilerException java.lang.ExceptionInInitializerError, compiling:(C:\dev\clojure\clojure-static-initialization\target\f31ee90298a1be447b450330204c3c0806c08b96-init.clj:1:10)

$ lein clean;lein repl
Compiling 1 source files to C:\dev\clojure\clojure-static-initialization\target\classes
Compiling clojure-static-initialization.gen-class-demo
Compiling clojure-static-initialization.proxy-demo
Running static initializers!
Clojure 1.9.0-master-SNAPSHOT

user=> (def jfxpanel (javafx.embed.swing.JFXPanel.))
#'user/jfxpanel
user=> (def lcp (proxy [javafx.scene.control.ListCell] []))
#'user/lcp

Comment by Terje Dahl [ 07/Sep/18 2:45 AM ]

I am not so sure that the fix is simply to a matter of swapping calling classForNameNonLoading a couple of places. proxy does some pretty sophisticated introspection and class analysis, which touches the static code in many places.

An alternative solution would be to have a proxy function - one which does the same as proxy but at runtime.
I currently have a workaround which works for the problem of JavaFX's ListCell ...

Comment by Terje Dahl [ 07/Sep/18 7:10 AM ]

The workaround: Delaying a macro evaluation from compile-time to run-time.
In this case, I am assuming that you have wrapped your proxy-call in a function and that it would be safe to do it at run-time (because you have init-ed your JavaFX or whatever):
1. Use a "back-tick" to prevent your macro from evaluation at compile-time.
2. Wrap your back-ticked code in an eval:

(defn make-thing []
  (eval
   `(proxy ...

3. Local bindings and function args need to be "gensym-ed" ...#.
4. Implisit this needs to be accessed as ~'this

(defn make-thing []
  (eval
   `(proxy [ListCell][]
     (updateItem [item# empty?#]
       (proxy-super updateItem item# empty?#)            
         (.setText ~'this nil)
         ...

5. args passed to the function need to be dynamically bound outside the eval, and perhaps rebound in a let inside the back-ticked code for accessing on seperate thread:

(def ^:dynamic *an-arg* nil)

(defn make-thing [an-arg]
  (binding [*an-arg* an-arg]
    (eval
    `(let [an-arg# *an-arg*]
      (proxy [ListCell][]
        (updateItem [item# empty?#]
          (proxy-super updateItem item# empty?#)            
           (.setText ~'this nil)
           (println "an-arg:" an-arg#)
           ...

Could this be done with a macro instead? E.g. proxyfn





[CLJ-2003] [spec] Nesting cat inside ? causes unform to return nested result Created: 11/Aug/16  Updated: 08/Oct/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.9
Fix Version/s: Release 1.11

Type: Defect Priority: Critical
Reporter: Sam Estep Assignee: Unassigned
Resolution: Unresolved Votes: 8
Labels: spec

Attachments: Text File CLJ-2003-corrected.patch     Text File CLJ-2003.patch    
Patch: Code and Test
Approval: Vetted

 Description   

Calling conform and then unform with a spec that consists of some cat nested inside of some ? creates an extra level of nesting in the result:

(require '[clojure.spec :as s])

(let [spec (s/? (s/cat :foo #{:foo}))
      initial [:foo]
      conformed (s/conform spec initial)
      unformed (s/unform spec conformed)]
  [initial conformed unformed])
;;=> [[:foo] {:foo :foo} [(:foo)]]

This behavior does not occur with just ? or cat alone:

(let [spec (s/? #{:foo})]
  (s/unform spec (s/conform spec [:foo])))
;;=> [:foo]

(let [spec (s/cat :foo #{:foo})]
  (s/unform spec (s/conform spec [:foo])))
;;=> (:foo)

Patch: CLJ-2003-corrected.patch



 Comments   
Comment by Phil Brown [ 14/Aug/16 9:55 PM ]

I came across another case of extra nesting, when repeating one or more sequences with an optional element at the beginning or end, where that element's predicate also matches the element at the other end:

user=> (s/conform (s/+ (s/cat :k any? :v (s/? any?))) [:a 1 :b 2])
[{:k :a, :v 1} [{:k :b, :v 2}]]

where I expected

[{:k :a, :v 1} {:k :b, :v 2}]

The following give expected results:

user=> (s/conform (s/+ (s/cat :k any? :v (s/? any?))) [:a 1 :b])
[{:k :a, :v 1} {:k :b}]
user=> (s/conform (s/+ (s/cat :k keyword? :v (s/? int?))) [:a 1 :b 2])
[{:k :a, :v 1} {:k :b, :v 2}]
user=> (s/conform (s/* (s/cat :k any? :v (s/? any?))) [:a 1 :b 2])
[{:k :a, :v 1} {:k :b, :v 2}]
Comment by Alex Miller [ 01/Sep/16 11:06 AM ]

Phil, I think your example is a different issue and you should file a new jira for that.

Comment by Alex Miller [ 01/Sep/16 3:05 PM ]

Well, maybe I take that back, they may be related.

Comment by Brandon Bloom [ 08/Nov/16 6:10 PM ]

I just ran in to this trying to make sense of some defn forms. Here's an example:

user=> (s/unform :clojure.core.specs/defn-args (s/conform :clojure.core.specs/defn-args '(f [& xs])))
(f ((& xs)))

Comment by Tyler Tallman [ 09/Aug/17 9:41 PM ]

This seems to be all that is needed.

Comment by Francis Avila [ 28/Aug/17 9:24 PM ]

The problem is actually more universal than (? (cat ...)). s/unform of a s/? with any regex child op will introduce an extra level of nesting. When the child is a regex, we are consuming the same "level" of sequence so unform should not introduce an extra level. However in other cases (non-regex ops), we should still possibly produce a nested collection.

The previous patch was too aggressive: it unwrapped all sub-unforms of s/?. This patch CLJ-2003-corrected.patch only unwraps when the sub-op is a regex.

Unfortunately it is impossible to distinguish between a desired-but-optional nil and a non-match from s/?. Specifically, the following tests now hold:

(testing "s/? matching nil"
  (is (nil? (s/conform (s/? nil?) [nil])))
  (is (nil? (s/conform (s/? nil?) [])))
  (is (nil? (s/conform (s/? nil?) nil)))
  (is (= (s/unform (s/? nil?) nil) [])))

(I did not add these tests to the patch because I was unsure if they should be part of the contract of unform. However, they are pretty big gotchas.)

I also added tests for every possible subop of s/?, except ::s/accept, which I could not think of a test case for. (I'm not sure ::s/accept is actually reachable inside s/op-unform?)

Comment by Alex Miller [ 29/Aug/17 7:33 AM ]

Thanks for working on this - I will take a look when I get a chance.

Comment by Francis Avila [ 29/Aug/17 9:20 AM ]

I had to amend my patch slightly (same name): one of the test cases wasn't testing the correct thing.

Comment by Francis Avila [ 31/Jul/18 1:12 PM ]

Patch was no longer applying cleanly to master because of tests added by other commits. Patch rebased to master





[CLJ-1891] New socket server startup proactively loads too much code, slowing boot time Created: 09/Feb/16  Updated: 08/Oct/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.8
Fix Version/s: Release 1.11

Type: Enhancement Priority: Critical
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 3
Labels: server

Attachments: Text File clj-1891.patch    
Patch: Code
Approval: Vetted

 Description   

In the new socket server code, clojure.core.server is proactively loaded (regardless of whether servers are in the config), which will also load clojure.edn and clojure.string.

Approach: Delay loading of this code until the first server config is found. This improves startup time when not using the socket server about 0.05 s.

Patch: clj-1891.patch



 Comments   
Comment by Alexander Yakushev [ 02/Jan/18 9:17 AM ]

Bump. With the introduction of Spec, and considering the fact that clojure.core.server triggers the initialization of Spec, the benefit of solving this issue should now be bigger than 0.05 sec (more like 0.2 sec). See http://clojure-goes-fast.com/blog/clojures-slow-start .





[CLJ-1611] clojure.java.io/pushback-reader Created: 08/Dec/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Feature Priority: Critical
Reporter: Phill Wolf Assignee: Unassigned
Resolution: Unresolved Votes: 14
Labels: io, reader

Attachments: Text File drupp-clj-1611-2.patch     Text File drupp-clj-1611.patch    
Approval: Triaged

 Description   

Whereas

  • clojure.core/read and clojure.edn/read require a PushbackReader;
  • clojure.java.io/reader produces a BufferedReader, which isn't compatible;
  • the hazard has tripped folks up for years[1];
  • clojure.java.io is pure sugar anyway (and would not be damaged by the addition of a little bit more);
  • clojure.java.io's very existence suggests suitability and fitness for use (wherein by the absence of a read-compatible pushback-reader it falls short);

i.e., in the total absence of clojure.java.io it would not seem "hard" to use clojure.edn, but in the presence of clojure.java.io and its "reader" function, amidst so much else in the API that does fit together, one keeps thinking one is doing it wrong;

and

  • revising the "read" functions to make their own Pushback was considered but rejected [2];

Therefore let it be suggested to add clojure.java.io/pushback-reader, returning something consumable by clojure.core/read and clojure.edn/read.

[1] The matter was discussed on Google Groups:

(2014, "clojure.edn won't accept clojure.java.io/reader?") https://groups.google.com/forum/#!topic/clojure/3HSoA12v5nc

with a reference to an earlier thread

(2009, "Reading... from a reader") https://groups.google.com/forum/#!topic/clojure/_tuypjr2M_A

[2] CLJ-82 and the 2009 message thread



 Comments   
Comment by David Rupp [ 10/Jan/15 4:05 PM ]

Attached patch drupp-clj-1611.patch implements clojure.java.io/pushback-reader as requested.

Comment by David Rupp [ 10/Jan/15 4:07 PM ]

Note that you can always import java.io.PushbackReader and do something like (PushbackReader. (reader my-thing)) yourself; that's really all the patch does.

Comment by Phill Wolf [ 11/Jan/15 7:54 AM ]

clojure.java.io/reader is idempotent, while the patch of 10-Jan-2015 re-wraps an existing PushbackReader twice: first with a new BufferedReader, then with a new PushbackReader.

Leaving a given PushbackReader alone would be more in keeping with the pattern of clojure.java.io.

It also needs a docstring. If pushback-reader were idempotent, the docstring's opening phrase could echo clojure.java.io/reader's, e.g.: Attempts to coerce its argument to java.io.PushbackReader; failing that, (bla bla bla).

Comment by David Rupp [ 11/Jan/15 11:14 AM ]

Adding drupp-clj-1611-2.patch to address previous comments.





[CLJ-2463] Improve error printing in clojure.main with -m, -e, etc Created: 04/Jan/19  Updated: 15/Mar/19

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.10
Fix Version/s: Release 1.10.1

Type: Enhancement Priority: Critical
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: error-reporting, main

Attachments: Text File clj-2463-2.patch     Text File clj-2463-3.patch     Text File clj-2463-4.patch     Text File clj-2463.patch    
Patch: Code
Approval: Screened

 Description   

Clojure 1.10 has a lot of improvements to print better errors in clojure.main when using the repl. However, these improvements do not extend to the default behavior when using other clojure.main modes like -m (run -main in a namespace), -e (run expression), or the script running option. All of these will simply let an exception throw out of the main and default to JVM behavior, which prints the stack of the full chain of exceptions.

Some practical ramifications of this are that anything in the ecosystem that is running Clojure programs via clojure.main (could be clj, but could also be other tools like "lein ring server" where I saw this happenn), these tools are not getting the advantages of the error improvements.

The general proposal is to catch Throwable around the call to the main entry point and at least run the Throwable->map, ex-triage, ex-str pipeline. Also need to consider what to do about printing the stack trace. The default JVM behavior is to print the stack of every exception in the chain, but printing either the root cause stack (in execution error) or no stack (in reader/compiler/macroexpansion cases) would likely be better.

Simple repro (note very long line of spec problem data that all gets spammed to the screen - have to scroll right to see it):

$ clj -e "(ns foo (import java.util.Date))"
Exception in thread "main" Syntax error macroexpanding clojure.core/ns at (1:1).
Call to clojure.core/ns did not conform to spec.
	at clojure.lang.Compiler.checkSpecs(Compiler.java:6971)
	at clojure.lang.Compiler.macroexpand1(Compiler.java:6987)
	at clojure.lang.Compiler.macroexpand(Compiler.java:7074)
	at clojure.lang.Compiler.eval(Compiler.java:7160)
	at clojure.lang.Compiler.eval(Compiler.java:7131)
	at clojure.core$eval.invokeStatic(core.clj:3214)
	at clojure.main$eval_opt.invokeStatic(main.clj:465)
	at clojure.main$eval_opt.invoke(main.clj:459)
	at clojure.main$initialize.invokeStatic(main.clj:485)
	at clojure.main$null_opt.invokeStatic(main.clj:519)
	at clojure.main$null_opt.invoke(main.clj:516)
	at clojure.main$main.invokeStatic(main.clj:598)
	at clojure.main$main.doInvoke(main.clj:561)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.lang.Var.applyTo(Var.java:705)
	at clojure.main.main(main.java:37)
Caused by: clojure.lang.ExceptionInfo: Call to clojure.core/ns did not conform to spec. {:clojure.spec.alpha/problems [{:path [], :reason "Extra input", :pred (clojure.spec.alpha/cat :docstring (clojure.spec.alpha/? clojure.core/string?) :attr-map (clojure.spec.alpha/? clojure.core/map?) :ns-clauses :clojure.core.specs.alpha/ns-clauses), :val ((import java.util.Date)), :via [:clojure.core.specs.alpha/ns-form], :in [1]}], :clojure.spec.alpha/spec #object[clojure.spec.alpha$regex_spec_impl$reify__2509 0x412c995d "clojure.spec.alpha$regex_spec_impl$reify__2509@412c995d"], :clojure.spec.alpha/value (foo (import java.util.Date)), :clojure.spec.alpha/args (foo (import java.util.Date))}
	at clojure.spec.alpha$macroexpand_check.invokeStatic(alpha.clj:705)
	at clojure.spec.alpha$macroexpand_check.invoke(alpha.clj:697)
	at clojure.lang.AFn.applyToHelper(AFn.java:156)
	at clojure.lang.AFn.applyTo(AFn.java:144)
	at clojure.lang.Var.applyTo(Var.java:705)
	at clojure.lang.Compiler.checkSpecs(Compiler.java:6969)
	... 15 more

As a macroexpansion spec error, this could just say:

$ clj -e "(ns foo (import java.util.Date))"
Syntax error macroexpanding clojure.core/ns at (1:1).
((import java.util.Date)) - failed: Extra input spec: :clojure.core.specs.alpha/ns-form

which would be much less scary.

Proposal: clojure.main is a process boundary. As such, the facilities for communicating information through it are limited to printing and the return value. Existing consumers of clojure.main are likely to be using the return value so that needs to be maintained. For the printing, we have expended a lot of energy to craft a good message for all phases in the 1.10 error message re-work, which is currently active at the repl. For other consumers of clojure.main, we wish to give them the same experience, but also want don't want to throw away the full exception chain / stack trace info for consumers that need it. In the repl, it's less critical to retain all info because further interactive calls can be made for pst or ex-data, but in a clojure.main exit, you're done.

As such, the attached patch saves all that information and puts it in a temp file (falling back to printing to stderr if the file can't be created) and prints just the error message you would get at the repl.

One additional change included in the patch is that the current ex-triage does not preserve and ex-str does not print the full path to the source file, just the file name itself. If the error is in, say core.clj, this is not helpful. So I've made an additive change there to also store the path and use it in the error message you see at both the REPL and in clojure.main.

For the example above, you'd see something like:

$ clj -e "(ns foo (import java.util.Date))"
Syntax error macroexpanding clojure.core/ns at (REPL:1:1).
((import java.util.Date)) - failed: Extra input spec: :clojure.core.specs.alpha/ns-form
Full report at: /var/folders/2k/2l7ch1xn7lb5gj86tgp1ygww0000gn/T/clojure-782738238888539988.edn

For an example with a namespace path:

$ clj -e "(require 'b.c)"
Syntax error (ArithmeticException) compiling at (b/c.clj:3:1).
Divide by zero
Full report at: /var/folders/2k/2l7ch1xn7lb5gj86tgp1ygww0000gn/T/clojure-8657942939058862044.edn

The temp file created is a readable .edn file which can be further processed by tooling if needed:

$ cat /var/folders/2k/2l7ch1xn7lb5gj86tgp1ygww0000gn/T/clojure-8657942939058862044.edn
{:clojure.main/message
 "Syntax error (ArithmeticException) compiling at (b/c.clj:3:1).\nDivide by zero\n",
 :clojure.main/triage
 {:clojure.error/phase :compile-syntax-check,
  :clojure.error/line 3,
  :clojure.error/column 1,
  :clojure.error/source "c.clj",
  :clojure.error/path "b/c.clj",
  :clojure.error/class java.lang.ArithmeticException,
  :clojure.error/cause "Divide by zero"},
 :clojure.main/trace
 {:via
  [{:type clojure.lang.Compiler$CompilerException,
    :message "Syntax error compiling at (b/c.clj:3:1).",
    :data
    {:clojure.error/phase :compile-syntax-check,
     :clojure.error/line 3,
     :clojure.error/column 1,
     :clojure.error/source "b/c.clj"},
    :at [clojure.lang.Compiler load "Compiler.java" 7647]}
   {:type java.lang.ArithmeticException,
    :message "Divide by zero",
    :at [clojure.lang.Numbers divide "Numbers.java" 188]}],
  :trace
  [[clojure.lang.Numbers divide "Numbers.java" 188]
   [clojure.lang.Numbers divide "Numbers.java" 3901]
   ...elided...
   [clojure.main main "main.java" 37]],
  :cause "Divide by zero",
  :phase :compile-syntax-check}}

Patch: clj-2463-4.patch



 Comments   
Comment by Alex Miller [ 04/Jan/19 2:17 PM ]

Attached a proof-of-concept hack at this. Needs more discussion about what to do about the stack traces, whether we can do a better job sharing code between clojure.main and clojure.repl/pst, and maybe should consider an option (like -x) to dump the full stack chain in case you need it for debugging.

Comment by Stuart Halloway [ 09/Feb/19 7:16 AM ]

It is important to keep in mind all the ways that clojure.main is different from the REPL. When running the REPL, you still have the process after an exception happens. If you don't like the way exceptions are presented, you can programmatically grab the exception and do whatever your want. You can use the new 1.10 tools or write your own.

When clojure.main exits, your process is gone. If we make any change at all (particularly eliding detail for human reader convenience), and somebody wants something different, then they are out of luck. Also, printing the stack trace as Java does (the current behavior) means we are operationally compatible with production tooling designed around Java processes.

Most of the reported pain people feel from this would be fixed by making a tiny number of changes in how Java processes are launched from lein, boot, Cursive, et al. On the other side of such changes, these tools would have independent and full control of how users experience errors. They could match 1.10 behavior or enhance it, separate from the Clojure release cycle. And they could make different choices in different contexts.

Comment by Alex Miller [ 09/Feb/19 2:18 PM ]

Ideally, there should be both a programmatic entry point and a command line wrapper entry point that prints rather than leaves it to the jvm.

Comment by Alex Miller [ 27/Feb/19 11:18 AM ]

Added updated -3 patch

Comment by Alex Miller [ 27/Feb/19 11:22 AM ]

Because leiningen relies on forking commands as a clojure.main process in many cases, this will also affect leiningen output. Example (annotated left column notes who is printing):

$ lein compile
LEIN  Compiling err.core
LEIN  Syntax error compiling at (err/core.clj:5:1).
CLJ   Syntax error compiling at (err/core.clj:5:1).
CLJ   Unable to resolve symbol: defnfoo in this context
CLJ   Full report at: /var/folders/2k/2l7ch1xn7lb5gj86tgp1ygww0000gn/T/clojure-12258630339337634263.edn
LEIN  Compilation failed: Subprocess failed

The double "Syntax error compiling" line is because Leiningen is printing in addition to clojure.main. Leiningen could take more control over what happens here if desired. Relevant code: https://github.com/technomancy/leiningen/blob/ba9d2ac9920e6622c944fcf223debbeadf85222d/src/leiningen/compile.clj#L150-L171

Comment by Alex Miller [ 01/Mar/19 11:18 AM ]

-4 patch adds explicit clojure.main option --report-stderr to force reporting to stderr





[CLJ-1965] [spec] clojure.spec/def should support an optional doc-string Created: 19/Jun/16  Updated: 08/Oct/18

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.9
Fix Version/s: Release 1.11

Type: Feature Priority: Critical
Reporter: Alexander Kiel Assignee: Unassigned
Resolution: Unresolved Votes: 67
Labels: spec

Approval: Vetted

 Description   

Like clojure.core/def clojure.spec/def should support an optional doc string because one usually likes to describe specs in more detail as one could through keyword naming.



 Comments   
Comment by Moritz Heidkamp [ 03/Nov/16 4:23 PM ]

Building on this idea, I suggest to add first-class metadata support to registered specs and implement doc strings in terms of that (i.e. the same way as with vars).

Comment by Josh Brandoff [ 01/Apr/17 5:02 PM ]

Hi! Was just discussing the potential for a feature like this with a colleague. What's the current status? Was thinking of potentially working on it but wanted to get feedback and guidance from the community first.

Comment by Alex Miller [ 03/Apr/17 9:32 AM ]

We don't have a recommended approach to this yet so not looking for a patch at this time.

Comment by Felix Andrews [ 19/Jun/18 7:30 PM ]

If you're prioritising this, please also remember the need for source (file + line) metadata on specs. This would enable us to use specs in auto generated documentation which is really nice, especially when you can hyperlink to nested specs. See CLJ-2037 https://dev.clojure.org/jira/browse/CLJ-2037





[CLJ-859] Built in dynamic vars don't have :dynamic metadata Created: 19/Oct/11  Updated: 24/Feb/12

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.3
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Anthony Simpson Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

I'm sure 'built in' is probably not the right term here, but I'm not sure what these are called.

I ran into this issue earlier today while fixing a bug in clojail. Built in vars, particularly ones listed here without a source link: http://clojure.github.com/clojure/clojure.core-api.html, do not have :dynamic metadata despite being dynamic. This includes *in*, *out*, and *err* among others. Here are some examples:

user=> (meta #'*err*)
{:ns #<Namespace clojure.core>, :name *err*, :added "1.0", :doc "A java.io.Writer object representing standard error for print operations.\n\n  Defaults to System/err, wrapped in a PrintWriter"}
user=> (meta #'*in*)
{:ns #<Namespace clojure.core>, :name *in*, :added "1.0", :doc "A java.io.Reader object representing standard input for read operations.\n\n  Defaults to System/in, wrapped in a LineNumberingPushbackReader"}
user=> (meta #'*out*)
{:ns #<Namespace clojure.core>, :name *out*, :added "1.0", :doc "A java.io.Writer object representing standard output for print operations.\n\n  Defaults to System/out, wrapped in an OutputStreamWriter", :tag java.io.Writer}
user=> (meta #'*ns*)
{:ns #<Namespace clojure.core>, :name *ns*, :added "1.0", :doc "A clojure.lang.Namespace object representing the current namespace.", :tag clojure.lang.Namespace}


 Comments   
Comment by Ben Smith-Mannschott [ 19/Oct/11 12:03 PM ]

This recent discussion on the users list seems relevant: Should intern obey :dynamic?.

It seems to boil down to this the information that a Var is dynamic (or not) is duplicated. Once as metadata with the key :dynamic, and once as a boolean field on the Var class which implements Clojure's variables. This boolean can be obtained by calling the method isDynamic() on the Var.

The confusion arises because apparently :dynamic and .isDynamic can get out of sync with each other. .isDynamic is the source of truth in this case.

Comment by Ben Smith-Mannschott [ 19/Oct/11 12:18 PM ]

Compiler$Parser.parse(...) finds the :dynamic entry left in the metadata of the symbol by LispReader and passes this on when creating a new DefExpr, which in turn, generates the code that will call setDynamic(...) on the var when it is created at runtime.

As far as I can tell, the :dynamic entry is irrelevant once that has occurred. It seems to be implemented only as a way to communicate (by way of the reader) with the compiler. Once the compiler's gotten the message, it isn't needed anymore. Keeping it around seems to just cause confusion.

Dynamic vars created by the Java layer of Clojure core don't use the :dynamic mechanism, they just setDynamic() directly. That's why they don't have :dynamic in their meta-data map.

  • Perhaps the compiler should elide :dynamic from the metadata map available at runtime, since it has served its purpose.
  • Perhaps Clojure should supply the function dynamic?.
    (defn dynamic? [^clojure.lang.Var v] (.isDynamic v))

Or, perhaps one might consider, for 1.4, replacing :dynamic altogether and just enforcing the established naming convention: *earmuffs* are dynamic, everything-else isn't. (The compile warns about violations of this convention in 1.3.)

Comment by Andy Fingerhut [ 24/Feb/12 11:39 AM ]

I recently noticed several lines like this one in core.clj. Depending upon how many symbols are like this, perhaps this method could be used to add :dynamic metadata to symbols in core, along with a unit test to verify that all symbols in core have :dynamic if and only if .isDynamic returns true?

Comment by Andy Fingerhut [ 24/Feb/12 12:41 PM ]

Ugh. In my previous comment, by "several lines like this one" I meant to paste the following as an example:

(alter-meta! #'agent assoc :added "1.0")





[CLJ-1016] Global scope overrides lexical scope for classes (Clojure assumes no classes in default package / Clojure cannot handle yFiles JARs in classpath) Created: 21/Jun/12  Updated: 24/May/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Edward Z. Yang Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None

Attachments: Text File collision-workaround.patch    

 Description   

The most visible symptom of this bug is having a class named 'w' (default package) in your classpath (such classes are produced by Java obfuscation tools such as yFiles) and then attempting to load Clojure's core class. For example:

java -cp hotspotapi.jar:clojure-1.4.0-slim.jar clojure.main

(where hotspotapi.jar is a stereotypical example of an obfuscated JAR) results in:

Exception in thread "main" java.lang.ExceptionInInitializerError
at clojure.main.<clinit>(main.java:20)
Caused by: java.lang.NoSuchFieldException: close, compiling:(clojure/core.clj:6139)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$TryExpr$Parser.parse(Compiler.java:2178)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5919)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5054)
at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3674)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.access$100(Compiler.java:37)
at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler.eval(Compiler.java:6515)
at clojure.lang.Compiler.load(Compiler.java:6952)
at clojure.lang.RT.loadResourceScript(RT.java:359)
at clojure.lang.RT.loadResourceScript(RT.java:350)
at clojure.lang.RT.load(RT.java:429)
at clojure.lang.RT.load(RT.java:400)
at clojure.lang.RT.doInit(RT.java:436)
at clojure.lang.RT.<clinit>(RT.java:318)
... 1 more
Caused by: java.lang.NoSuchFieldException: close
at java.lang.Class.getField(Class.java:1537)
at clojure.lang.Compiler$StaticFieldExpr.<init>(Compiler.java:1180)
at clojure.lang.Compiler$HostExpr$Parser.parse(Compiler.java:923)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
... 37 more
Could not find the main class: clojure.main. Program will exit.

To understand what is going on, consider this simple test:

import java.io.StringReader;

import clojure.lang.Compiler;
import clojure.lang.RT;

public class Test {
public static void main(String[] args) { RT.var("clojure.core", "require"); String s = "(let [mumble (new java.io.StringReader \"\")] (. mumble close))"; Compiler.load(new StringReader(s)); }
}

It should be clear that 'mumble' in the dot operator is referencing the locally defined mumble. However, if we define a class named 'mumble' in the default package, Clojure picks that one up instead.

To forestall any objections: yes, we know that placing classes in the default package is extremely poor form. Point of the matter is, the Java ecosystem is extremely diverse and there are a lot of JARs people may not have control over. While one might argue, "Don't put classes in the default namespace", point of the matter is, Clojure is wrong here, and these situations arise in practice, through no fault of the implementer.



 Comments   
Comment by Edward Z. Yang [ 21/Jun/12 11:01 AM ]

Here is a workaround patch which makes this error less likely to occur.

Comment by Andy Fingerhut [ 27/Aug/12 7:37 PM ]

Edward, it is Rich Hickey's policy only to consider for inclusion in Clojure patches written by people who have signed a Contributor Agreement: http://clojure.org/contributing

Were you interested in becoming a contributor?

Comment by Edward Z. Yang [ 27/Aug/12 9:24 PM ]

Sure, although the patch attached is emphatically not the one you want to actually applying, since it only band-aids the problem.

Comment by Andy Fingerhut [ 24/May/13 1:21 PM ]

I am not sure, but this ticket may be related to CLJ-1171. At least, there the issue was a global name not being shadowed by a local name bound with let. That seems similar to this issue.





[CLJ-113] GC Issue 109: RT.load's "don't load if already loaded" mechanism breaks ":reload-all" Created: 17/Jun/09  Updated: 26/Aug/13

Status: In Progress
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Anonymous Assignee: Stephen C. Gilardi
Resolution: Unresolved Votes: 0
Labels: None


 Description   
Reported by scgilardi, Apr 24, 2009

What (small set of) steps will reproduce the problem?

"require" and "use" support a ":reload-all" flag that is intended to  
cause the specified libs to be reloaded along with all libs on which  
they directly or indirectly depend. This is implemented by temporarily  
binding a "loaded-libs" var to the empty set and then loading the  
specified libs.

AOT compilation added another "already loaded" mechanism to  
clojure.lang.RT.load() which is currently not sensitive to a "reload-
all" being in progress and breaks its operation in the following case:

        A, B, and C are libs
        A depends on B. (via :require in its ns form)
        B depends on C. (via :require in its ns form)
        B has been compiled (B.class is on classpath)

        At the repl I "require" A which loads A, B, and C (either from
class files or clj files)
        I modify C.clj
        At the repl I "require" A with the :reload-all flag, intending to  
pick up the changes to C
        C is not reloaded because RT.load() skips loading B: B.class
exists, is already loaded, and B.clj hasn't changed since it was compiled.


What is the expected output? What do you see instead?

I expect :reload-all to be effective. It isn't.

What version are you using?

svn 1354, 1.0.0RC1

Was this discussed on the group? If so, please provide a link to the
discussion:

http://groups.google.com/group/clojure/browse_frm/thread/9bbc290321fd895f/e6a967250021462a#e6a967250021462a

Please provide any additional information below.

I'll upload a patch soon that creates a "*reload-all*" var with a  
root binding of nil and code to bind it to true when the current  
thread has a :reload-all call pending. When *reload-all* is true,  
RT.load() will (re)load all libs from their ".clj" files even if  
they're already loaded.

The fix for this may need to be coordinated with a fix for issue #3.


 Comments   
Comment by Assembla Importer [ 24/Aug/10 3:45 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/113

Comment by Assembla Importer [ 24/Aug/10 3:45 AM ]

richhickey said: Updating tickets (#8, #19, #30, #31, #126, #17, #42, #47, #50, #61, #64, #69, #71, #77, #79, #84, #87, #89, #96, #99, #103, #107, #112, #113, #114, #115, #118, #119, #121, #122, #124)

Comment by Assembla Importer [ 24/Aug/10 3:45 AM ]

richhickey said: Updating tickets (#8, #42, #113, #2, #20, #94, #96, #104, #119, #124, #127, #149, #162)

Comment by Kevin Downey [ 08/Aug/11 7:40 PM ]

seems like the code that is emitted in the static init for namespace classes could be emitted into a init_ns() static method and the static init could call init_ns(). then RT.load could call init_ns() to get the behavior of reloading an AOT compiled namespace.

Comment by Kevin Downey [ 09/Aug/11 8:31 PM ]

looking at the compiler it looks like most of what I mentioned above is already implemented, just need RT to reflectively call load() on the namespace class in the right place





[CLJ-396] Better support for multiple inheritance in hierarchies and multimethods Created: 07/Jul/10  Updated: 26/Aug/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

While the hierarchies produced with 'derive' allow multiple parents per child, there is no way to indicate precedence between those parents, other than by laboriously specifying 'prefer-method' for every type X every multimethod. When 2 multimethods are both applicable to the supplied arguments, Clojure produces a nonspecific IllegalArgumentException containing only an error string. All this means that while Clojure does have an "inheritance" mechanism in the form of the ad hoc hierarchies, it is currently not really possible to implement multiple inheritance using the ad hoc hierarchy mechanism. 'Prefer-method' will not scale up to use in large applications with complex type hierarchies and heavy use of multimethods.

Some potential ways to solve this are:

  • allowing 'defmulti' to take a 'tie-breaker' function (tie-breaker [arglist speclist1 speclist2] ...) which is called instead of throwing an IllegalArgumentException, and must return the 'winning speclist'.
  • instead of throwing IllegalArgumentException, throw a TiedMultiMethodsException – the exception instance should contain the offending speclists, the function, and the arguments that were supplied.
  • allowing specification of precedence when using 'derive' (if only via a "last in = highest precedence" rule).

Paul



 Comments   
Comment by Assembla Importer [ 24/Aug/10 11:06 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/396





[CLJ-319] TransactionalHashMap bug Created: 26/Apr/10  Updated: 26/Aug/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

TransactionalHashMap computation of the bin is buggy. The implementation doesn't unset the sign bit before using it in accessing the bin array which in some cases cause an ArrayOutOfBoundException to be thrown.

As Rich Hickey has pointed out, this is an unsupported experimental Class and won't be fixed unless I provided a patch, so attached is the patch file.



 Comments   
Comment by Assembla Importer [ 01/Oct/10 4:06 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/319
Attachments:
TransactionalHashMap.java.patch - https://www.assembla.com/spaces/clojure/documents/cuuZnsuuWr36H0eJe5dVir/download/cuuZnsuuWr36H0eJe5dVir

Comment by Assembla Importer [ 01/Oct/10 4:06 PM ]

megabyte2021 said: [file:cuuZnsuuWr36H0eJe5dVir]: The patch file

Comment by Assembla Importer [ 01/Oct/10 4:06 PM ]

stu said: Please add a test case.





[CLJ-1136] Type hinting for array classes does not work in binding forms Created: 20/Dec/12  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4, Release 1.5
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Luke VanderHart Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: interop, typehints
Environment:

replicated on OpenJDK 7u9 on Ubuntu 12.04, and Hotspot 1.6.0_37 on OSX Lion



 Description   

Type hints don't work as expected in binding forms.

The following form results in a reflection warning:

(let [^{:tag (Class/forName "[Ljava.lang.Object;")} a (make-array Object 2)]
(aget a 0))

However, hinting does appear to work correctly on vars:

(def ^{:tag (Class/forName "[Ljava.lang.Object;")} a (make-array Object 2))
(aget a 0) ;; no reflection warning



 Comments   
Comment by Ghadi Shayban [ 20/Dec/12 10:51 PM ]

It's a little more insidious than type hinting: the compiler doesn't evaluate metadata in the binding vec.

This doesn't throw the necessary exception...

(let [^{:foo (Class/forName "not real")} bar 42]
bar)

neither this...

(let [^{gyorgy ligeti} a 42]
a)

Gyorgy Ligeti never resolves.

These two equivalent examples don't reflect:
(let [^objects a (make-array Object 2)]
(aget a 0))

(let [a ^objects (make-array Object 2)]
(aget a 0))

Comment by Ghadi Shayban [ 21/Dec/12 11:09 AM ]

On only the left-hand side of a local binding, metadata on a symbol is not analyzed or evaluated.





[CLJ-1001] Proxy cannot call proper super-class method Created: 23/May/12  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.2, Release 1.3
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Guanpeng Xu Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: interop
Environment:

Linux herberteuler 3.2.0-2-amd64 #1 SMP Sat May 12 23:08:28 UTC 2012 x86_64 GNU/Linux


Attachments: File proxy-bug.clj    

 Description   

Attached is a program that reproduces this issue. We have a proxy, `p', which sub-classes java.io.InputStream. There are three methods named `read' in java.io.InputStream: abstract int read(); int read(byte[] b); and int read(byte[] b, int off, int len); see http://docs.oracle.com/javase/6/docs/api/java/io/InputStream.html. In the definition of proxy `p', we implement the abstract variant of method `read', making `p' a concrete instance of java.io.InputStream.

The first invocation, (. p read), returns -1, which is expected.

The second invocation, (. p (read b 0 n)), should call int read(byte[] b, int off, int len); in java.io.InputStream. But these are actual behavior:

$ clojure1.2 ~/tmp/proxy-bug.clj
Exception in thread "main" java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn (proxy-bug.clj:0)
at clojure.lang.Compiler.eval(Compiler.java:5441)
at clojure.lang.Compiler.load(Compiler.java:5858)
at clojure.lang.Compiler.loadFile(Compiler.java:5821)
at clojure.main$load_script.invoke(main.clj:221)
at clojure.main$script_opt.invoke(main.clj:273)
at clojure.main$main.doInvoke(main.clj:354)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.lang.Var.invoke(Var.java:365)
at clojure.lang.AFn.applyToHelper(AFn.java:161)
at clojure.lang.Var.applyTo(Var.java:482)
at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn
at clojure.lang.AFn.throwArity(AFn.java:437)
at clojure.lang.AFn.invoke(AFn.java:51)
at user.proxy$java.io.InputStream$0.read(Unknown Source)
at user$eval1.invoke(proxy-bug.clj:9)
at clojure.lang.Compiler.eval(Compiler.java:5425)
... 10 more

$ clojure1.2 ~/tmp/proxy-bug.clj
Exception in thread "main" java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn (proxy-bug.clj:0)
at clojure.lang.Compiler.eval(Compiler.java:5441)
at clojure.lang.Compiler.load(Compiler.java:5858)
at clojure.lang.Compiler.loadFile(Compiler.java:5821)
at clojure.main$load_script.invoke(main.clj:221)
at clojure.main$script_opt.invoke(main.clj:273)
at clojure.main$main.doInvoke(main.clj:354)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.lang.Var.invoke(Var.java:365)
at clojure.lang.AFn.applyToHelper(AFn.java:161)
at clojure.lang.Var.applyTo(Var.java:482)
at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn
at clojure.lang.AFn.throwArity(AFn.java:437)
at clojure.lang.AFn.invoke(AFn.java:51)
at user.proxy$java.io.InputStream$0.read(Unknown Source)
at user$eval1.invoke(proxy-bug.clj:9)
at clojure.lang.Compiler.eval(Compiler.java:5425)
... 10 more



 Comments   
Comment by Guanpeng Xu [ 23/May/12 10:24 PM ]

The second behavior should be in Clojure 1.3:

$ clojure1.3 ~/tmp/proxy-bug.clj
Exception in thread "main" clojure.lang.ArityException: Wrong number of args (4) passed to: user$eval1$fn
at clojure.lang.AFn.throwArity(AFn.java:437)
at clojure.lang.AFn.invoke(AFn.java:51)
at user.proxy$java.io.InputStream$0.read(Unknown Source)
at user$eval1.invoke(proxy-bug.clj:9)
at clojure.lang.Compiler.eval(Compiler.java:6468)
at clojure.lang.Compiler.load(Compiler.java:6905)
at clojure.lang.Compiler.loadFile(Compiler.java:6866)
at clojure.main$load_script.invoke(main.clj:282)
at clojure.main$script_opt.invoke(main.clj:342)
at clojure.main$main.doInvoke(main.clj:426)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.lang.Var.invoke(Var.java:401)
at clojure.lang.AFn.applyToHelper(AFn.java:161)
at clojure.lang.Var.applyTo(Var.java:518)
at clojure.main.main(main.java:37)

Sorry for the inconvenience.

Comment by Russell Mull [ 01/Sep/13 3:12 AM ]

Verified with Clojure 1.5.1:

Stack Trace
clojure.lang.ArityException: Wrong number of args (4) passed to: user$eval147$fn
                                      AFn.java:437 clojure.lang.AFn.throwArity
                                       AFn.java:51 clojure.lang.AFn.invoke
                                  (Unknown Source) user.proxy/java.io.InputStream[fn]
                                  NO_SOURCE_FILE:9 user/eval147
                                Compiler.java:6619 clojure.lang.Compiler.eval
                                Compiler.java:6582 clojure.lang.Compiler.eval
                                     core.clj:2852 clojure.core/eval
                                      main.clj:259 clojure.main/repl[fn]
                                      main.clj:259 clojure.main/repl[fn]
                                      main.clj:277 clojure.main/repl[fn]
                                      main.clj:277 clojure.main/repl
                                  RestFn.java:1096 clojure.lang.RestFn.invoke
                         interruptible_eval.clj:56 clojure.tools.nrepl.middleware.interruptible-eval/evaluate[fn]
                                      AFn.java:159 clojure.lang.AFn.applyToHelper
                                      AFn.java:151 clojure.lang.AFn.applyTo
                                      core.clj:617 clojure.core/apply
                                     core.clj:1788 clojure.core/with-bindings*
                                   RestFn.java:425 clojure.lang.RestFn.invoke
                         interruptible_eval.clj:41 clojure.tools.nrepl.middleware.interruptible-eval/evaluate
                        interruptible_eval.clj:171 clojure.tools.nrepl.middleware.interruptible-eval/interruptible-eval[fn]
                                     core.clj:2330 clojure.core/comp[fn]
                        interruptible_eval.clj:138 clojure.tools.nrepl.middleware.interruptible-eval/run-next[fn]
                                       AFn.java:24 clojure.lang.AFn.run
                      ThreadPoolExecutor.java:1110 java.util.concurrent.ThreadPoolExecutor.runWorker
                       ThreadPoolExecutor.java:603 java.util.concurrent.ThreadPoolExecutor$Worker.run
                                   Thread.java:722 java.lang.Thread.run




[CLJ-1022] gen-class destroys method annotations Created: 03/Jul/12  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Maris Orbidans Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: interop


 Description   

When extending a class gen-class doesn't preserve method annotations.

If class com.bar.Foo has annotated methods then in MyClass all annotations are gone.

(gen-class
:name com.my.MyClass
:extends com.bar.Foo
:implements [com.google.common.base.Supplier]
:prefix demo-
:post-init post-init)

(defn demo-post-init [this]
(info "initialized")
(swank.swank/start-server :port 68478))

(defn demo-get [_]
(get-msg))

Class<?> aClass = Class.forName("com.my.MyClass");
Method[] methods = aClass.getMethods();

for (Method m : methods) {
Annotation[] annotations = m.getAnnotations();
System.out.println(m.getName()+" "+annotations.length);
for (Annotation a : annotations) { System.out.println(a.annotationType().getClass().getName()); }
}






[CLJ-400] A faster flatten Created: 13/Jul/10  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: performance


 Description   

As discussed in this thread, I am submitting a more performant version of flatten for review. It has the same semantics as the current core/flatten. I have also updated the doc string to say that "(flatten nil) returns the empty list", because that's what the current version of core/flatten does as well.

I haven't mailed in a CA yet, but I will tomorrow morning.

Edit: Of course I'd mess my first ticket up . I am not immediately seeing an option to edit this to add the "patch" tag or add the "ready to test" action. Sorry folks



 Comments   
Comment by Assembla Importer [ 24/Aug/10 12:19 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/400
Attachments:
flatten-enhancement.diff - https://www.assembla.com/spaces/clojure/documents/c5chtAJQir353NeJe5cbLr/download/c5chtAJQir353NeJe5cbLr





[CLJ-277] Making clojure.xml/emit a little friendler to xml consumers Created: 03/Mar/10  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: xml


 Description   

Currently, clojure.xml/emit breaks the eBay api, because emit adds whitespace before and after :contents. This trivial patch fixes it for me:
http://github.com/tjg/clojure/commit/bbff079d26e627c655b847319a58d76b8b3cec7c

(Dunno whether there's a good reason emit works that way, or if I'm missing something obvious.)

I realize that emit's behavior conforms to the XML spec and it's probably eBay at fault here. But I can nevertheless see this whitespace causing problems.



 Comments   
Comment by Assembla Importer [ 24/Aug/10 9:41 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/277

Comment by Assembla Importer [ 24/Aug/10 9:41 AM ]

bpsm said: I've attached a patch to #410, which also fixes this issue. (In fact, it turns out that it's the same patch tlj previously attached here.)

Comment by Assembla Importer [ 24/Aug/10 9:41 AM ]

stu said: Duplicated association with ticket #410 was added





[CLJ-163] Enhance = and == docs Created: 30/Jul/09  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Laurent Petit
Resolution: Unresolved Votes: 0
Labels: docstring


 Description   

Enhance = and == docs as far as numbers handling is concerned (make them self referenced, make clear what == offers beyond = -except that it will only work for numbers)



 Comments   
Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/163
Attachments:
fixbug163.diff - https://www.assembla.com/spaces/clojure/documents/bH0XMCFjur3PLMeJe5aVNr/download/bH0XMCFjur3PLMeJe5aVNr

Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

laurentpetit said: [file:bH0XMCFjur3PLMeJe5aVNr]

Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

richhickey said: I don't want to recommend, in = doc, that people should prefer == for any case. People should always prefer =. If there is a perf, difference we can make that go away. Then the only difference with == is that it will fail on non-numbers, and that should be the only reason to choose it.

Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

richhickey said: Updating tickets (#94, #96, #104, #119, #163)

Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

laurentpetit said: Richn, by "will fail on non-numbers", do you mean "should throw an exception" (and thus the patch must change the code), or just as it works today :

(== :a :a)
false

?

Comment by Assembla Importer [ 24/Aug/10 1:04 PM ]

richhickey said: I've fixed the code so == on non-numbers throws





[CLJ-150] Doc for array-map should mention its characteristics/caveats Created: 10/Jul/09  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: docstring


 Description   

Doc for array-map should mention its characteristics: preserves order of keys, linear O search so appropriate only for small maps, operations on array-maps return hash-maps.



 Comments   
Comment by Assembla Importer [ 24/Aug/10 4:54 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/150





[CLJ-19] GC Issue 15: JavaDoc for interfaces Created: 17/Jun/09  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: documentation


 Description   
Reported by richhickey, Dec 17, 2008
Add JavaDoc to those interfaces supported for public use - IFn,
IPersistentCollection etc.


 Comments   
Comment by Assembla Importer [ 24/Aug/10 6:44 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/19

Comment by Assembla Importer [ 24/Aug/10 6:44 AM ]

richhickey said: Updating tickets (#8, #19, #30, #31, #126, #17, #42, #47, #50, #61, #64, #69, #71, #77, #79, #84, #87, #89, #96, #99, #103, #107, #112, #113, #114, #115, #118, #119, #121, #122, #124)

Comment by Kevin Downey [ 17/Nov/12 8:05 PM ]

this seems like a great task for someone just starting out contributing to clojure.





[CLJ-1045] Generalize/refactor implementation of PersistentVector/coll-fold Created: 18/Aug/12  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Alan Malloy Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reducers

Attachments: Text File clj-1045-fold-by-halves-patch-v2.txt     Text File fold-by-halves.patch    
Patch: Code

 Description   

Vector currently contains a specialized implementation of the folding algorithm "split the collection in half until the pieces are small enough". The attached commit lifts out the general strategy so that it can be reused by other collection types amenable to splitting.

CLJ-993 depends on this patch, as it uses the new fold-by-halves function.



 Comments   
Comment by Andy Fingerhut [ 25/Jan/13 2:29 PM ]

clj-1045-fold-by-halves-patch-v2.txt dated Jan 25 2013 is identical to fold-by-halves.patch dated Aug 18 2012, except it updates one line of context changed by a recent commit to Clojure master.





[CLJ-978] bean unable to handle non-public classes Created: 30/Apr/12  Updated: 05/Feb/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Charles Duffy Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: None

Attachments: File clojure--bean-support-for-private-implementation-classes-v3.diff    
Patch: Code and Test

 Description   

Take the following Java as an example:

public interface IFoo {
  String getBar();
}

class FooImpl {
  String getBar() { return "bar"; }
}

As presently implemented, (bean my-foo) tries to invoke the following:

(. #<Method public java.lang.String FooImpl.getBar> (invoke my-foo nil))

However, as FooImpl is not public, this fails:

java.lang.IllegalAccessException: Class clojure.core$bean$fn__1827$fn__1828 can not access a member of class FooImpl with modifiers "public"
 at sun.reflect.Reflection.ensureMemberAccess (Reflection.java:65)
    java.lang.reflect.Method.invoke (Method.java:588)
    clojure.core$bean$fn__1827$fn__1828.invoke (core_proxy.clj:382)
    clojure.core$bean$v__1832.invoke (core_proxy.clj:388)
    clojure.core$bean$fn__1838$thisfn__1839$fn__1840.invoke (core_proxy.clj:406)
    clojure.lang.LazySeq.sval (LazySeq.java:42)
    clojure.lang.LazySeq.seq (LazySeq.java:60)
    clojure.lang.RT.seq (RT.java:473)

However, the same thing succeeds if we call #<Method public java.lang.String Foo.getBar> rather than #<Method public java.lang.String FooImpl.getBar>.



 Comments   
Comment by Charles Duffy [ 30/Apr/12 10:40 PM ]

Fix inaccurate documentation string

Comment by Charles Duffy [ 01/May/12 9:41 AM ]

Apache Commons Beanutils has their own implementation of this, at http://www.docjar.com/html/api/org/apache/commons/beanutils/MethodUtils.java.html#771 – notably, it tries to reflect a method with the given signature and catches the exception on failure, rather than iterating through the whole list. This may be a better approach – I'm unfamiliar with how the cost of exception handling compares with that of reflecting on the full method list of a class.

Comment by Charles Duffy [ 01/May/12 10:11 AM ]

Prior version of patch were missing new test suite files. Corrected.

Comment by Andy Fingerhut [ 04/May/12 2:48 AM ]

Thanks for the patches, Charles. Could you please create a patch in the desired format and attach that, and then remove the obsolete patches? Instructions for creating a patch are under the heading "Development" at this page: http://dev.clojure.org/display/design/JIRA+workflow

Instructions for removing patches are under the heading "Removing patches" on that same page.

Comment by Charles Duffy [ 06/May/12 2:59 PM ]

Added a patch created per documented process.

Comment by Gary Trakhman [ 04/Oct/12 6:44 PM ]

I found in my code that it's possible to get a NPE if there is no read-method, for instance on the http://docs.cascading.org/cascading/2.0/javadoc/cascading/flow/hadoop/HadoopFlow.html object which has a setCascade method but no getter. I fixed this in our code by inlining the is-zero-args check into the public-method definition and and-ing the whole thing with 'method' like the original 'bean' code, like so:

public-method (and method (zero? (alength (. method (getParameterTypes))))
(or (and (java.lang.reflect.Modifier/isPublic (. c (getModifiers)))
method)
(public-version-of-method method)))

Comment by Rich Hickey [ 29/Nov/12 10:01 AM ]

Charles, I think we should follow Apache BeanUtils on this. Exceptions not thrown are cheap. Ordinarily, exception for control flow are bad, but this is forced by bad design of reflection API.





[CLJ-1431] Switch from MurmurHash3 to SipHash to prevent DoS collision attack (hash flooding) Created: 25/May/14  Updated: 26/May/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4, Release 1.5, Release 1.6
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: James Thornton Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: security


 Description   

Clojure is using Murmur3 throughout:
https://github.com/clojure/clojure/commit/dff9600387b962f16fc78e6477e10e34651fd366

DJB, Jean-Philippe Aumasson, and Martin Boßlet have shown that Murmur3 is not resilient against hash collision attacks:
http://www.ocert.org/advisories/ocert-2012-001.html
https://131002.net/siphash/

"Hash-flooding DoS reloaded: attacks and defenses" talk by DJB, Jean-Philippe Aumasson, and Martin Boßlet
http://media.ccc.de/browse/congress/2012/29c3-5152-en-hashflooding_dos_reloaded_h264.html

"Breaking Murmur: Hash-flooding DoS Reloaded"
http://emboss.github.io/blog/2012/12/14/breaking-murmur-hash-flooding-dos-reloaded/

Python, Ruby, JRuby, Haskell, Rust, Perl, Redis... have all switched to SipHash
https://en.wikipedia.org/wiki/SipHash

Last year Google dropped CityHash from Guava and replaced it with SipHash
https://code.google.com/p/guava-libraries/issues/detail?id=1232

SipHash Guava Implementation
https://code.google.com/p/guava-libraries/source/browse/guava/src/com/google/common/hash/SipHashFunction.java

SipHash Java reference implementation
https://github.com/emboss/siphash-java/blob/master/src/main/java/com/github/emboss/siphash/SipHash.java



 Comments   
Comment by Alex Miller [ 26/May/14 12:56 AM ]

Thanks, we've talked about this issue and some possible things we could do, but didn't have a ticket for it yet.

Comment by Alex Miller [ 26/May/14 1:08 AM ]

While the Java 7 approach relied on (attempting) to properly seed hash maps with string hash codes, that was all dropped in Java 8, which addressed DoS collision hash attacks by instead improving the data structure to switch from linear collisions to a red/black tree (log-time) for collisions. It's possible a similar approach could work in Clojure as well.

One workaround that could be used now is to wrap map keys in a custom type that implements IHashEq and implements an alternate hash function.





[CLJ-1221] Should repackage jsr166 and include known version with Clojure Created: 20/Jun/13  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Alex Miller Assignee: Alex Miller
Resolution: Unresolved Votes: 0
Labels: reducers


 Description   

Clojure 1.5 reducers work with either the JDK version of forkjoin (JDK 1.7+) or with an external jsr166 jar. This causes complexity for users and complexity in the build to deal with the two options.

jsr166 code is public domain and it is common for other projects to repackage the handful of files and ship it with the project (similar to what we do with asm). This would allow us just use a known existing version of jsr166 across all jdks and we could get rid of the custom build wrangling we introduced in Clojure 1.5.

jsr166y is compatible with JDK 1.6+ and is the version that (for example) Scala currently repackages. That's the best choice for JDK 1.6 and 1.7. In JDK 1.8, the best choice will (temporarily) be the built-in version in java.util.concurrent which tracks jsr166e but then as soon as there are updates will become jsr166e. Many fork/join fixes are ported to both y and e right now.

Some choices here for JDK 1.8:

  • go for maximal compatibility just use repackaged jsr166y regardless of JDK (simplest)
  • check for jdk version # and use java.util.concurrent instead
  • check for jdk version # and repackage jsr166e and use it instead

Not sure yet which of these is best choice right now.






[CLJ-1504] Add :inline to most core predicates Created: 15/Aug/14  Updated: 15/Aug/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None

Attachments: Text File 0001-add-inline-to-some-core-predicates.patch    
Patch: Code

 Description   

This will allow instance? predicates calls to be emitted using the instanceof JVM bytecode and will also allow tools like core.typed or tools.analyzer.jvm to infer the type of a var/local on a per branch basis without having to special-case all the core predicates.



 Comments   
Comment by Jozef Wagner [ 15/Aug/14 1:32 PM ]

Related ticket CLJ-1227 and related quote from Alex:

definline is considered to be an experimental feature and Rich would like to discourage its use as the hope is to remove it in the future. The desired replacement is something like common lisp compiler macros that could allow the compiler to detect special situations and optimize the result but leave behind a function invocation for the case where no special behavior is available.

Comment by Nicola Mometto [ 15/Aug/14 1:42 PM ]

This patch uses "manual" :inline metadata on functions, it's used by many other core functions (like +,- et), not definline so Rich's comment doesn't apply.





[CLJ-1536] Remove usage of sun.misc.Signal (which may not be available in Java 9) Created: 26/Sep/14  Updated: 26/Sep/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

It looks like Java 9 will not continue to provide access to "internal" classes like sun.misc.Signal. Clojure currently uses this in the REPL to trap ctrl-c (SIGINT) and cancel current evaluation instead of process shutdown.

There is a page of alternatives here:
https://wiki.openjdk.java.net/display/JDK8/Java+Dependency+Analysis+Tool

But there is no suggested alternative for sun.misc.Signal and I'm not aware of a portable solution to it.






[CLJ-1582] Overriding in-ns and ns is problematic Created: 07/Nov/14  Updated: 07/Nov/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: None

Attachments: Text File 0001-Allow-overriding-of-clojure.core-in-ns-and-clojure.c.patch    
Patch: Code

 Description   

Currently it is possible to override clojure.core/in-ns and clojure.core/ns, but it is not possible to refer to the namespace-specific vars without fully qualifying them:

user=> (ns foo (:refer-clojure :exclude [in-ns]))
nil
foo=> (def in-ns 1)
#'foo/in-ns
foo=> in-ns
#<clojure.lang.RT$1@76b5e4c5>

After this patch, overriding in-ns and ns works like for every other clojure.core var:

user=> (ns foo (:refer-clojure :exclude [in-ns]))
nil
foo=> (def in-ns 1)
#'foo/in-ns
foo=> in-ns
1


 Comments   
Comment by Reid McKenzie [ 07/Nov/14 11:46 AM ]

This is motivated by https://github.com/jonase/eastwood/issues/100





[CLJ-1612] clojure.core.reducers/mapcat can call f1 with undefined arity of 0 arguments? Created: 10/Dec/14  Updated: 10/Dec/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6, Release 1.7
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Andy Fingerhut Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reducers


 Description   

I have not run across this with running code, so perhaps it is impossible for reasons I have not understood. Also not sure whether fixing issues with reducers is of any importance, given transducers. This was found while testing the Eastwood lint tool on some Clojure namespaces, including clojure.core.reducers.

(defcurried mapcat
  "Applies f to every value in the reduction of coll, concatenating the result
  colls of (f val). Foldable."
  {:added "1.5"}
  [f coll]
  (folder coll
   (fn [f1]
     (let [f1 (fn
                ([ret v]
                  (let [x (f1 ret v)] (if (reduced? x) (reduced x) x)))
                ([ret k v]
                  (let [x (f1 ret k v)] (if (reduced? x) (reduced x) x))))]
       (rfn [f1 k]
            ([ret k v]
               (reduce f1 ret (f k v))))))))

The definition of macro rfn expands to a (fn ...) that can call f1 with no arguments, which is not a defined arity for f1.






[CLJ-1037] Allow doc strings for both interfaces and concrete implementations Created: 04/Aug/12  Updated: 17/Apr/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Warren Lynn Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

In this post
http://groups.google.com/group/clojure/browse_thread/thread/84de74740928da76#

I mentioned the rationale (I think) why this is important and needed. Thank you for consideration.



 Comments   
Comment by Kevin Downey [ 17/Apr/14 10:08 PM ]

clojure's documentation system has two parts:

1. docstrings are attached to the metadata of objects

2. the doc macro (and some other tools) read the docstrings from objects and display them

the two parts work together, without the doc macro, docstrings are just comments that also take up memory at runtime, and the doc macro has no purpose without the docstrings.

the two main places docstrings are hung are var metadata and namespace metadata.

for multimethods and protocol functions the docstrings are hung on vars.

for the implementations of multimethods and protocols there are no distinct vars to hang documentation information on, and it is not clear how you would look up those doc strings.

so to support docs on defmethods and protocol implementations would require enhancements to doc and some design work, so a wiki page to come up with a design would be a good idea.





[CLJ-1376] Initialize internal maps to more efficient version Created: 11/Mar/14  Updated: 11/Mar/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: performance


 Description   

In reviewing some hashing stuff, I noticed that there are many places internal to Clojure that use maps initialized with PersistentHashMap.EMPTY. Many of these maps are likely to have a small number of entries such that a PersistentArrayMap might be more efficient.

These are the candidates:

src/jvm/clojure/lang/ARef.java
19:private volatile IPersistentMap watches = PersistentHashMap.EMPTY;

src/jvm/clojure/lang/Compiler.java
3009:				IPersistentMap m = PersistentHashMap.EMPTY;
3819:					       KEYWORDS, PersistentHashMap.EMPTY,
3820:					       VARS, PersistentHashMap.EMPTY,
3964:	IPersistentMap closes = PersistentHashMap.EMPTY;
3977:	IPersistentMap keywords = PersistentHashMap.EMPTY;
3978:	IPersistentMap vars = PersistentHashMap.EMPTY;
5121:                            ,CLEAR_SITES, PersistentHashMap.EMPTY
7259:			       KEYWORDS, PersistentHashMap.EMPTY,
7260:			       VARS, PersistentHashMap.EMPTY
7418:			IPersistentMap opts = PersistentHashMap.EMPTY;
7475:			IPersistentMap fmap = PersistentHashMap.EMPTY;
7522:					       KEYWORDS, PersistentHashMap.EMPTY,
7523:					       VARS, PersistentHashMap.EMPTY,
7912:                            ,CLEAR_SITES, PersistentHashMap.EMPTY

src/jvm/clojure/lang/LispReader.java
755:					RT.map(GENSYM_ENV, PersistentHashMap.EMPTY));

src/jvm/clojure/lang/MultiFn.java
39:	this.methodTable = PersistentHashMap.EMPTY;
41:	this.preferTable = PersistentHashMap.EMPTY;
49:		methodTable = methodCache = preferTable = PersistentHashMap.EMPTY;

src/jvm/clojure/lang/Var.java
48:	final static Frame TOP = new Frame(PersistentHashMap.EMPTY, null);
175:	setMeta(PersistentHashMap.EMPTY);
341:	IPersistentMap ret = PersistentHashMap.EMPTY;

Approach: Two possible approaches - initialize to PersistentArrayMap.EMPTY or call RT.map(). The latter requires function invocation so is slightly slower, but has the benefit of localizing map construction into a single place.






[CLJ-77] GC Issue 74: Clojure compiler emits too-large classfiles (results in ClassFormatError) Created: 17/Jun/09  Updated: 23/Feb/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Chas Emerick Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: errormsgs


 Description   
Reported by cemer...@snowtide.com, Feb 10, 2009

The jvm has certain implementation limits around the maximum size of
classfiles, literal strings, method length, etc; however, in certain
circumstances, the Clojure compiler can currently emit classfiles that
violate some of those limitations, causing an error later when the
classfile is loaded.

While test coverage would necessarily detect this sort of problem on a
project-by-project basis when one's tests attempted to load a project's
classfiles, it seems like Clojure should do the following to ensure failure
as quickly as possible:

- throw an exception immediately if, while compiling a lib, it is detected
that the resulting classfile(s) would violate any classfile implementation
limits.  Ideally, the exception's message would detail what file and on
which line number the offending form is (e.g. if a method's bytecode would
be too long).  I can imagine that doing this may not be straightforward; a
reasonable stop-gap would be for the compiler to immediately attempt to
load the generated classfile in order to ensure up-front failure.

- emit a warning if any clojure form is read that would, upon being
compiled, require violating any of the classfile implementation limits; I
suspect that *most* people looking to generate classfiles would be doing so
in a "build" environment (rather than loading some code, tinkering, and
then using clojure.core/compile), but for those that aren't, I can imagine
there being a good deal of frustration around seeing that loading and using
some code successfully would eventually produce unusable classfiles.

I've appended a sample stack trace emitted by java when it attempted to
load a too-long method implementation (which was produced by embedding a
large list literal in a compiled lib).

Exception in thread "main" java.lang.ClassFormatError: Invalid method  
Code length 105496 in class file com/foo/MyClass__init
         at java.lang.ClassLoader.defineClass1(Native Method)
         at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
         at  
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
         at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
         at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
         at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
         at java.security.AccessController.doPrivileged(Native Method)
         at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
         at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:
288)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
         at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:
374)
         at java.lang.Class.forName0(Native Method)
         at java.lang.Class.forName(Class.java:247)
         at clojure.lang.RT.loadClassForName(RT.java:1512)
         at clojure.lang.RT.load(RT.java:394)
         at clojure.lang.RT.load(RT.java:374)
         at clojure.core$load__4911$fn__4913.invoke(core.clj:3623)
         at clojure.core$load__4911.doInvoke(core.clj:3622)
         at clojure.lang.RestFn.invoke(RestFn.java:413)
         at clojure.core$load_one__4863.invoke(core.clj:3467)
         at clojure.core$compile__4918$fn__4920.invoke(core.clj:3633)
         at clojure.core$compile__4918.invoke(core.clj:3632)
         at clojure.lang.Var.invoke(Var.java:336)
         at clojure.lang.Compile.main(Compile.java:56)


 Comments   
Comment by Assembla Importer [ 24/Aug/10 6:45 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/77

Comment by Assembla Importer [ 24/Aug/10 6:45 AM ]

richhickey said: Updating tickets (#8, #19, #30, #31, #126, #17, #42, #47, #50, #61, #64, #69, #71, #77, #79, #84, #87, #89, #96, #99, #103, #107, #112, #113, #114, #115, #118, #119, #121, #122, #124)





[CLJ-1674] Boolean return type-hint confusing the compiler Created: 12/Mar/15  Updated: 12/Mar/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Mikkel Kamstrup Erlandsen Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: typehints
Environment:

OSX, Clojure 1.6.0



 Description   

Saving the below snippet and running it like

java -jar clojure-1.6.0.jar snippet.clj

Produces

$ java -jar clojure-1.6.0.jar snippet.clj 
Exception in thread "main" java.lang.IllegalArgumentException: Unable to resolve classname: clojure.core$boolean@1356d4d4, compiling:(/Users/kamstrup/tmp/snippet.clj:15:1)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6651)
	at clojure.lang.Compiler.analyze(Compiler.java:6445)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6632)
	at clojure.lang.Compiler.analyze(Compiler.java:6445)
	at clojure.lang.Compiler.access$100(Compiler.java:38)
	at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:538)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6644)
	at clojure.lang.Compiler.analyze(Compiler.java:6445)
	at clojure.lang.Compiler.analyze(Compiler.java:6406)
	at clojure.lang.Compiler.eval(Compiler.java:6707)
	at clojure.lang.Compiler.load(Compiler.java:7130)
	at clojure.lang.Compiler.loadFile(Compiler.java:7086)
	at clojure.main$load_script.invoke(main.clj:274)
	at clojure.main$script_opt.invoke(main.clj:336)
	at clojure.main$main.doInvoke(main.clj:420)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.lang.Var.invoke(Var.java:379)
	at clojure.lang.AFn.applyToHelper(AFn.java:154)
	at clojure.lang.Var.applyTo(Var.java:700)
	at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Unable to resolve classname: clojure.core$boolean@1356d4d4
	at clojure.lang.Compiler$HostExpr.tagToClass(Compiler.java:1069)
	at clojure.lang.Compiler$InvokeExpr.getJavaClass(Compiler.java:3659)
	at clojure.lang.Compiler$LocalBinding.hasJavaClass(Compiler.java:5657)
	at clojure.lang.Compiler$LocalBindingExpr.hasJavaClass(Compiler.java:5751)
	at clojure.lang.Compiler.maybePrimitiveType(Compiler.java:1283)
	at clojure.lang.Compiler$IfExpr.doEmit(Compiler.java:2631)
	at clojure.lang.Compiler$IfExpr.emit(Compiler.java:2613)
	at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5826)
	at clojure.lang.Compiler$LetExpr.doEmit(Compiler.java:6180)
	at clojure.lang.Compiler$LetExpr.emit(Compiler.java:6133)
	at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5826)
	at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5374)
	at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5232)
	at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3771)
	at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4410)
	at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3904)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6642)
	... 19 more

The snippet:

snippet.clj
;; Bug in the Clojure compiler (1.6.0): If we annotate the return here with ^boolean we get:
;; 'IllegalArgumentException: Unable to resolve classname: clojure.core$boolean' from the compiler.
;; Removing it, everything is as expected
(defn ^boolean foo-bar?
  [node]
  (= node "foo-bar"))

;; Check it out, we can have ^boolean here, but not on foo-bar? !! :-)
(defn ^boolean bar-foo?
  [node]
  (= node "bar-foo"))

;; Instead of removing the ^boolean return on foo-bar? we can also remove this function
;; to have all work as expected
(defn ^boolean interesting?
  [node]
  (or (foo-bar? node) (bar-foo? node)))

(println "Foo-Bar?" (foo-bar? "baz"))


 Comments   
Comment by Mikkel Kamstrup Erlandsen [ 12/Mar/15 5:25 AM ]

Typo in comment 2 in the snippet: s/xtc-scenario?/foo-bar?/

Comment by Nicola Mometto [ 12/Mar/15 6:01 AM ]

Metadata on def's symbol is evaluated as per the doc (http://clojure.org/special_forms), evaluating `boolean` results in the clojure.core/boolean function which is not a valid type hint.

As a rule of thumb, attach the return tag in the argvec rather than on the def symbol, in this case you should write

(defn foo-bar?
   ^boolean [node]
  (= node "foo-bar"))

I understand why the fact that

(defn ^boolean foo [] true)

and

(defn foo ^boolean [] true)

behave differently and the fact that the compiler will throw iff the type hint is used rather than throwing at the function definition time is confusing (and I've complained about this and the lack of documentation/specification regarding type hints for a while) but this is not a bug

Comment by Mikkel Kamstrup Erlandsen [ 12/Mar/15 6:36 AM ]

Thanks for clarifying Nicola, you are indeed correct.

Putting return type annotations before the method name seems to be common practice in a lot of Clojure code I've read online. Perpetuated by some online tutorials, and the clojure.org docs them selves (fx.

(defn ^:private ^String my-fn ...)
is found in http://clojure.org/cheatsheet)

Comment by Andy Fingerhut [ 12/Mar/15 8:36 AM ]

Mikkel: If the type tags are Java classes, not primitives, then ^Classname is a correct type tag. If you use Eastwood, it can warn about these incorrect type tags, and has some documentation on what works and what does not here: https://github.com/jonase/eastwood#wrong-tag

Also here: https://github.com/jonase/eastwood#unused-meta-on-macro





[CLJ-140] Single :tag for type hints conflates value's type with type of return value from an invoke Created: 01/Jul/09  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: typehints


 Description   

The value of a Var can be operated on directly, or, if it is a fn, it can be invoked and the resulting value operated on. :tag metadata on a Var is used to provide a type hint to the compiler to avoid reflection. Having a single metadata key for this two distinct uses makes it possible (even easy, if unlikely) to create a situation where type-hinting the value causes a ClassCastException on an operation on the invocation return value, or the reverse. The only obvious solution is two use different keys for the two uses.



 Comments   
Comment by Assembla Importer [ 24/Aug/10 3:51 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/140





[CLJ-1707] conditional form is not consumed when :read-allow is falsey Created: 15/Apr/15  Updated: 15/Apr/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reader


 Description   
user=> (def a (java.io.PushbackReader. (java.io.StringReader. "#?(:clj [1 2])")))
#'user/a
user=> (read a)
RuntimeException Conditional read not allowed  clojure.lang.Util.runtimeException (Util.java:221)
user=> (read a)
(:clj [1 2])

the expected result would be an EOF exception on the second read.






[CLJ-1701] Serialization of protocol methods broken: java.io.NotSerializableException: clojure.lang.MethodImplCache Created: 13/Apr/15  Updated: 20/Apr/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6, Release 1.7
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Dr. Christian Betz Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

With this test, you can see that we cannot serialize methods from protocols (i.e. time-from-tweet), as this results in a java.io.NotSerializableException: clojure.lang.MethodImplCache
at java.io.ObjectOutputStream.writeObject0 (ObjectOutputStream.java:1183)
java.io.ObjectOutputStream.defaultWriteFields (ObjectOutputStream.java:1547)
java.io.ObjectOutputStream.writeSerialData (ObjectOutputStream.java:1508)
java.io.ObjectOutputStream.writeOrdinaryObject (ObjectOutputStream.java:1431)
java.io.ObjectOutputStream.writeObject0 (ObjectOutputStream.java:1177)
java.io.ObjectOutputStream.writeObject (ObjectOutputStream.java:347)
sparkling.protocol_test$serialize.invoke (protocol_test.clj:11)

This is the actual test:

(ns sparkling.protocol-test
(:require [clojure.test :refer :all])
(:import [java.io ObjectInputStream ByteArrayInputStream ObjectOutputStream ByteArrayOutputStream]))

(defn- serialize
"Serializes a single object, returning a byte array."
[v]
(with-open [bout (ByteArrayOutputStream.)
oos (ObjectOutputStream. bout)]
(.writeObject oos v)
(.flush oos)
(.toByteArray bout)))

(defn- deserialize
"Deserializes and returns a single object from the given byte array."
[bytes]
(with-open [ois (-> bytes ByteArrayInputStream. ObjectInputStream.)]
(.readObject ois)))

(defprotocol timestamped
(time-from-tweet [item]))

(defrecord tweet [username tweet timestamp]
timestamped
(time-from-tweet [_]
timestamp
))

(deftest sequable-serialization
(testing "Serialization of function"
(let [item identity]
(is item (-> item serialize deserialize))))

(testing "Serialization of protocol method"
(let [item time-from-tweet]
(is item (-> item serialize deserialize)))))



 Comments   
Comment by Dr. Christian Betz [ 13/Apr/15 6:15 AM ]

BTW: Same is true for multimethods, here the exception is java.io.NotSerializableException: clojure.lang.MultiFn

Comment by Alex Miller [ 13/Apr/15 9:35 AM ]

I don't think we expect functions to be serializable in this way. Both protocols and multimethods effectively have runtime state based on what implementations have extended them. What would it mean to serialize these functions? Would you serialize them with whatever implementations have been loaded at that point? Or with none? Both seem problematic to me. Regular functions are closures and can capture the state of their environment. I think better answers are either AOT or for regular functions, something like the serializable-fn library.

Comment by Dr. Christian Betz [ 13/Apr/15 1:13 PM ]

Hi,

thanks for the comments. First, something to the background: I'm developing Sparkling, a Clojure API to Apache Spark. For distributing code in the cluster it depends on AOT compiled functions, so yes, you cannot simply serialize any function around, it needs to be AOT'd. Serializiation provides us with support for the current bindings etc, and everything works as expected. So, AFunction is serializable for a reason and so are other implementations of AFn/IFn, everything works well.

Regarding the state of protocols and multimethods - I think it's conceptually the same as the state of functions (which function definition, the var might be bound multiple times, etc.), and the closures given in bindings. There's no reason for me as the user of a protocol to believe that the method from the protocol differs from a function. In fact (ifn? protocol-method) also returns true.

serializable-fn, not being intended for over-the-wire serialization in the first place, has problems with collections of functions in bindings of the serializble function, together with an issue with PermGen pollution by creating classes for the same function over and over again in the context of Spark.

I think I'm fine for the moment, as I can wrap the protocol method in a function, but I still believe, that this is a bug.

Regards

Chris

Comment by Dr. Christian Betz [ 20/Apr/15 3:10 AM ]

actually, this is the code snippet from clojure.lang.AFunction causing the pain:

clojure.lang.AFunction.java
public abstract class AFunction extends AFn implements IObj, Comparator, Fn, Serializable {

public volatile MethodImplCache __methodImplCache;

AFunction is serializable, but MethodImplCache is not. I'm not sure if it's enough to mark it as transient, because I did not check where initialization happens.

Comment by Dr. Christian Betz [ 20/Apr/15 3:29 AM ]

My comment per mail got lost in SMTP-nirvana: There's an easy workaround. Wrap the protocol method in a function, that will do the trick at the cost of uglifying your code





[CLJ-1721] Enable test case for char? Created: 03/May/15  Updated: 03/May/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Brandon Bloom Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: patch

Attachments: Text File CLJ-1721_v01.patch    
Patch: Code and Test

 Description   

clojure.core/char? already exists, but there was no test for it (despite a comment suggesting one).






[CLJ-1774] Field access on typed record does not preserve type Created: 02/Jul/15  Updated: 03/Jul/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Michael Blume Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: defrecord, reflection, typehints


 Description   
(ns field-test.core
  (:import [java.util UUID]))

(defrecord UUIDWrapper [^UUID uuid])

(defn unwrap [^UUIDWrapper w]
  (.-uuid w)) ; <- No reflection

(defn get-lower-bits [^UUIDWrapper w]
  (-> w .-uuid .getLeastSignificantBits)) ; <- Reflection :(

The compiler seems to have all the information it needs, but lein check prints

Reflection warning, field_test/core.clj:10:3 - reference to field getLeastSignificantBits on java.lang.Object can't be resolved.

(test case also at https://github.com/MichaelBlume/field-test)



 Comments   
Comment by Alex Miller [ 02/Jul/15 4:31 PM ]

afaik, that ^UUID type hint on the record field doesn't do anything. The record field will be of type Object (only ^double and ^long affect the actual field type).

Perhaps more importantly, it is bad form to use Java interop to retrieve the field values of a record. Keyword access for that is preferred.

Comment by Nicola Mometto [ 03/Jul/15 4:48 AM ]

The same issue applies for deftypes where keyword access is not an option

Comment by Alex Miller [ 03/Jul/15 12:17 PM ]

Per http://clojure.org/datatypes: "You should always program to protocols or interfaces -
datatypes cannot expose methods not in their protocols or interfaces"

Along those lines, usually for deftypes, I gen an interface with the proper types if necessary, then have the deftype implement the interface to expose the field.

Also per http://clojure.org/datatypes:

"note that currently a type hint of a non-primitive type will not be used to constrain the field type nor the constructor arg, but will be used to optimize its use in the class methods" - that is, inside a method implemented on the record/type, referring to the field should have the right hint. So in the example above, if unwrap was an interface or protocol implementation method on the record, and you referred to the field, you should expect the hint to be utilized in that scenario.

So, my contention would be that all of the behavior described in this ticket should be expected based on the design, which is why I've reclassified this as an enhancement, not a defect.





[CLJ-1779] Optimise compiler usage of getMethod calls Created: 17/Jul/15  Updated: 17/Jul/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Mike Anderson Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

Currently the Clojure compiler makes multiple redundant calls to Method.getMethod(...) while emitting code, e.g.

gen.invokeStatic(Type.getType(Long.class), Method.getMethod("Long valueOf(long)"));

It seems to be the case that that:

a) These getMethod calls are effectively returning equivalent, immutable constant values
b) getMethod is moderately expensive (performs string analysis and quite a few object allocations)
c) These calls are very common during compilation of typical Clojure code

The proposed enhancement is to replace all of these getMethod calls with constant static values. This should improve compilation performance noticeably with no effect on behaviour.






[CLJ-457] lazy recursive definition giving incorrect results Created: 13/Oct/10  Updated: 03/Aug/15

Status: Reopened
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Assembla Importer Assignee: Christophe Grand
Resolution: Unresolved Votes: 0
Labels: None

Attachments: File CLJ-457-2.diff     File clj-457-3.diff    
Patch: Code and Test

 Description   

If you define a global data var in terms of a lazy sequence referring to that same var, you can get different results depending on the chunkiness of laziness of the functions being used to build the collection.

Clojure's lazy sequences don't promise to support this, but they shouldn't return wrong answers. In the example given in http://groups.google.com/group/clojure/browse_thread/thread/1c342fad8461602d (and repeated below), Clojure should not return bad data. An error message would be good, and even an infinite loop would be more reasonable than the current behavior.

(Similar issue reported here: https://groups.google.com/d/topic/clojure/yD941fIxhyE/discussion)

(def nums (drop 2 (range Long/MAX_VALUE)))
(def primes (cons (first nums)
             (lazy-seq (->>
               (rest nums)
               (remove
                 (fn [x]
                   (let [dividors (take-while #(<= (* % %) x)
primes)]
                     (println (str "primes = " primes))
                     (some #(= 0 (rem x %)) dividors))))))))
(take 5 primes)

It prints out:
(primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
2 3 5 7 9)


 Comments   
Comment by Assembla Importer [ 13/Oct/10 3:00 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/457

Comment by Aaron Bedra [ 10/Dec/10 9:08 AM ]

Stu and Rich talked about making this an error, but it would break some existing code to do so.

Comment by Rich Hickey [ 17/Dec/10 8:03 AM ]

Is there a specific question on this?

Comment by Aaron Bedra [ 05/Jan/11 9:05 PM ]

Stu, you and I went over this but I can't remember exactly what the question was here.

Comment by Christophe Grand [ 28/Nov/12 12:24 PM ]

Tentative patch attached.
Have you an example of existing code which is broken by such a patch (as mention by Aaron Bedra)?

Comment by Rich Hickey [ 30/Nov/12 9:43 AM ]

The patch intends to do what? We have only a problem description and code. Please enumerate the plan rather than make us decipher the patch.

As a first principle, I don't want Clojure to promise that such recursively defined values are possible.

Comment by Christophe Grand [ 30/Nov/12 10:23 AM ]

The proposal here is to catch recursive seq realization (ie when computing the body of a lazy-seq attempts to access the same seq) and throw an exception.

Currently when such a case happens, the recursive access to the seq returns nil. This results in incorrect code seemingly working but producing incorrect results or even incorrect code producing correct results out of luck (see https://groups.google.com/d/topic/clojure/yD941fIxhyE/discussion for such an example).

So this patch moves around the modification to the LazySeq state (f, sv and s fields) before all potentially recursive method call (.sval in the while of .seq and .invoke in .sval) so that, upon reentrance, the state of the LazySeq is coherent and able to convey the fact the seq is already being computed.

Currently a recursive call may find f and sv cleared and concludes the computation is done and the result is in s despite s being unaffected yet.

Currently:

State f sv s
Unrealized not null null null
Realized null null anything
Being realized/recursive call from fn.invoke not null null null
Being realized/recursive call from ls.sval null null null

Note that "Being realized" states overlap with Unrealized or Realized.
(NB: "anything" includes null)

With the patch:

State f sv s
Unrealized not null null null
Realized null null anything but this
Being realized null null this
Comment by Andy Fingerhut [ 30/Nov/12 2:06 PM ]

That last comment, Christophe, goes a long way to explaining the idea to me, at least. Any chance comments with similar content could be added as part of the patch?

Comment by Christophe Grand [ 03/Dec/12 11:18 AM ]

New patch with a comment explaining the expected states.
Note: I tidied the states table up.

// Before calling user code (f.invoke() in sval and, indirectly,
// ((LazySeq)ls).sval() in seq -- and even RT.seq() in seq), ensure that 
// the LazySeq state is in one of these states:
//
// State            f          sv
// ================================
// Unrealized       not null   null
// Realized         null       null
// Being realized   null       this

CLJ-1119 is also fixed by this patch.

Comment by Andy Fingerhut [ 23/Nov/13 12:35 AM ]

Patch clj-457-3.diff is identical to Christophe's CLJ-457-2.diff, except it has been updated to no longer conflict with the commit made for CLJ-949 on Nov 22, 2013, which basically removed the try/catch in method sval(). It passes tests, and I don't see anything wrong with it, but it would be good if Christophe could give it a look, too.

Comment by Alex Miller [ 02/Aug/15 7:46 PM ]

No longer reproducible

Comment by Nicola Mometto [ 03/Aug/15 10:01 AM ]

Alex, the posted example is no longer reproducible because `(range)` does not produce a chunked-seq anymore.
OTOH `(range n)` does so replacing `(range)` with something like `(range Long/MAX_VALUE)` in the code example in the ticket description is sufficient to resurface the bug:

Clojure 1.8.0-master-SNAPSHOT
user=> (def nums (drop 2 (range Long/MAX_VALUE)))
#'user/nums
(def primes (cons (first nums)
             (lazy-seq (->>
               (rest nums)
               (remove
                 (fn [x]
                   (let [dividors (take-while #(<= (* % %) x)
primes)]
                     (println (str "primes = " primes))
                     (some #(= 0 (rem x %)) dividors))))))))
#'user/primes
user=> (take 5 primes)
(primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
2 3 5 7 9)




[CLJ-968] ns emitting gen-class before imports results in imported annotations being discarded. Created: 09/Apr/12  Updated: 03/Sep/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.3, Release 1.4
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Charles Duffy Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: interop


 Description   

The following discards the imported annotations:

(ns com.example.BaseXModuleTest
  (:import (org.basex.query QueryModule QueryModule$Deterministic))
  (:gen-class
     :extends org.basex.query.QueryModule
     :methods [
       [^{QueryModule$Deterministic {}}
        addOne [int] int]]))

However, when moving the gen-class call out of the ns declaration, the annotation is correctly applied:

(ns com.example.BaseXModuleTest
  (:import (org.basex.query QueryModule QueryModule$Deterministic)))

(gen-class
  :extends org.basex.query.QueryModule
  :name com.example.BaseXModuleTest
  :methods [
    [^{QueryModule$Deterministic {}}
     addOne [int] int]])

It appears that imported names are not yet in-scope when gen-class is run from a ns declaration.






[CLJ-1661] Varargs protocol impls can be defined but not called Created: 17/Feb/15  Updated: 09/Oct/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Reno Reckling Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None

Attachments: Text File CLJ-1661-v1.patch    
Patch: Code
Approval: Triaged

 Description   

The compiler accepts this:

(deftype foo []
clojure.lang.IFn
(invoke [this & xs]))

However calling ((foo.) :bar) will throw an AbstractMethodError. Wouldn't some checking be desirable?



 Comments   
Comment by Reno Reckling [ 17/Feb/15 11:09 AM ]

This is a clone of http://dev.clojure.org/jira/browse/CLJ-1024 because the original with its attached patches was forgotten with the reason that "It has to wait and cannot be applied in 1.5" which is 2 major versions ago now, with 1.7 underway.

I would like to reopen it, or continue working on it in this ticket because i just stumbled over this issue the second time and the debugging sessions that follow this are annoying.

Comment by Andy Fingerhut [ 19/Feb/15 12:23 PM ]

Fix Version/s was Release 1.5, but that field should only be set by Clojure screeners.

Comment by Reno Reckling [ 19/Feb/15 12:41 PM ]

Yes, i just cloned the original issue. Later i realized that I'm unable to edit any of the fields.
The issue is just concerned with a missing warning/error when trying to compile protocols with "&" in the argument list as they are interpreted as a variable name "&" instead of a varargs placeholder which the user probably expects.

Comment by Michael Blume [ 19/Feb/15 2:17 PM ]

Here's a forward-port of the 1024 patch





[CLJ-969] Symbol/keyword implements IFn for lookup but a non-collection argument produces non-intuitive results Created: 09/Apr/12  Updated: 20/Nov/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Sean Corfield Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: errormsgs

Attachments: Text File CLJ-969.patch    

 Description   

('+ 1 2) ;; return 2 because it is treated as (get 1 '+ 2)

Whilst this is "consistent" once you know the lookup behavior, it's confusing for Clojure newbies and it seems to be a non-useful behavior.

Proposal: modify Keyword.invoke() and Symbol.invoke() to restrict first Object argument to instanceof ILookup, Map or IPersistentSet (or null) so that the "not found" behavior doesn't produce non-intuitive behavior.

This should track CLJ-1107.



 Comments   
Comment by zjhmale [ 20/Nov/15 1:45 AM ]

a patch to fix this issue

Comment by zjhmale [ 20/Nov/15 1:46 AM ]

for now

user=> ('+ 1 2)
IllegalArgumentException class java.lang.Long is not lookupable: clojure.lang.Symbol.throwNotLookupable (Symbol.java:127)
user=> (:+ 1 2)
IllegalArgumentException class java.lang.Long is not lookupable: clojure.lang.Keyword.throwNotLookupable (Keyword.java:103)

and everything else works fine





[CLJ-1784] Reflector.getMethods should be cached Created: 21/Jul/15  Updated: 11/Dec/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Vladimir Sitnikov Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None

Attachments: Text File clj-1784.patch    

 Description   

Currently Reflector.getMethods performs expensive logic that includes java.lang.reflect.Method copying.
See: https://github.com/clojure/clojure/blob/b8607d5870202034679cda50ec390426827ff692/src/jvm/clojure/lang/Reflector.java#L373

In our application I see the following back-traces:

at Reflector.copyMethods
at Reflector.invokeInstanceMethod
at ...

These kind of backtraces are second top consumers of all the heap allocation.

JDK cannot cache Methods / Fields since they are mutable (e.g. user can call setAccessible here and there).
However, for the purposes of Clojure, I believe it should be fine to cache Methods and Fields.

What do you think?
E.g. WeakHashMap<Class, WeakReference<List<Method>>> or more sophisticated structure to account String name.



 Comments   
Comment by Alex Miller [ 23/Jul/15 8:19 AM ]

If you are seeing Reflector as a hot spot in your application, you should probably turn on warn-on-reflection and use type hints to avoid reflection.

Comment by Vladimir Sitnikov [ 28/Jul/15 6:10 AM ]

Do you mean there is absolutely no reason to use reflection in Clojure ever?
I do understand that if developer gives enough type hints the reflection would go away.

However:
1) I just do not know if it is easily doable (in other words, if it is possible at all, maintainable, etc)
2) I'm not sure if "always use type hints" is considered a best practice. For instance, warn-on-reflection documentation page says nothing like "always use type hints"
3) Caching copyMethods seems to be a low-hanging fruit here, so it would shave cpu cycles for those who omitted type hints

PS. I'm a java performance engineer, not a Clojure engineer (as in "my Clojure knowledge is somewhere near (+ x y)"), so I kindly beg on your forgiveness for me not doing RTFM.

Comment by Alex Miller [ 28/Jul/15 7:44 AM ]

No, I'm saying that if reflection is a hotspot in your application, usually it's worth investing a few minutes to add type hints in those hotspot areas and this is common advice for Clojure apps. Once that minimal work is done, few Clojure apps are bound by reflection.

Caching seems like an easy solution until you consider all of the management aspects. How does the cache get cleaned? Are the instances mutable and able to be reused? Are there cases where class loaders or code reloading create unexpected side effects? What are the concurrency effects of putting a shared resource in the invocation path? What is the memory impact of a cache and is it configurable?

Those are all things that would need to be investigated, meaning that this is not low-hanging fruit.

Comment by Mike Anderson [ 08/Dec/15 8:39 PM ]

Patch for simple caching of Reflector.getMethods calls for small arities

Comment by Mike Anderson [ 08/Dec/15 8:46 PM ]

I created a small patch to add very simple (fixed size, 1 element for each arity) caching for Reflector.getMethods calls. The aim is to keep this super simple to avoid issues like concurrency effects and having a variable-sized cache.

This helps a small amount in my tests (about 15-20%) on reflection calling the same method in a loop, which is probably the common case where people actually care about reflection performance.

Performance could certainly be improved further due to the fact that I think most of the overhead is actually is the `invokeMatchingMethod`, but that is an orthogonal issue. This patch opens the way for further performance optimisation in that area.

;; clojure 1.8.0-RC3
user=> (let [v (identity 1)] (time (dotimes [i 1000] (.doubleValue v))))
"Elapsed time: 1.598779 msecs"

;; with cached arities
user=> (let [v (identity 1)] (time (dotimes [i 1000] (.doubleValue v))))
"Elapsed time: 1.359888 msecs"

Comment by Vladimir Sitnikov [ 09/Dec/15 2:24 AM ]

Mike Anderson, I wonder if your patch results in a performance regression for concurrent workload.

You've created a single point of contention as lots of threads will try to update private static InstanceMethodCache[] instanceMethodCache entries, so it will hit both "true sharing" and "false sharing" problems.

Should instanceMethodCache be final and written in capital letters?

Comment by Alex Miller [ 09/Dec/15 10:33 AM ]

This ticket needs a better problem definition. That is: "I am doing ____" (with an example) that shows Reflector.getMethods() as the bottleneck.

If I guess at what the problem is, I remain unconvinced that this is the best solution.

A ThreadLocal is likely the cache solution with the lowest concurrency impact.

Comment by Mike Anderson [ 09/Dec/15 9:00 PM ]

This shouldn't have any noticeable concurrency impact: no locking is required for this very simple approach. Most of the time it is simply an unlocked read from an array on the heap, the Java memory model is enough to guarantee correct behaviour. That's cheaper than even a threadlocal, e.g. there's some evidence here that this is 10-20x faster: http://stackoverflow.com/questions/609826/performance-of-threadlocal-variable

At the very least, any concurrency impact is so tiny it will be dwarfed by the benefits of often avoiding the getMethods calls, which are expensive. The cost of array access is a few nanoseconds compared to the cost of getMethods which appears from the benchmark above to be a few hundred nanoseconds.

The worst concurrency case I can think of is the case where two different threads are calling getMethods on different methods at a high rate and these calls are perfectly interleaved so that they always invalidate the cache. But even in that case, it's probably not measurably worse than the current code.

@Vladimir yes, insntanceMethodCache could be final. Might help the JVM very marginally, I guess.

@Alex, I proposed this patch because it is an improvement over what is currently there, I certainly don't think it will be the "best possible solution". In the spirit of open source and making incremental progress, I'd like you to consider accepting it, even if this issue stays open for future consideration. This is also linked to clj-1866, I'm trying to make the "fast path" for reflection better in a few different ways. If you'd rather have a single large patch with a whole bunch of improvements I can certainly do that, I has under the impression that smaller, more "obvious" patches would be easier for you to review but happy either way.

Comment by Vladimir Sitnikov [ 10/Dec/15 1:18 AM ]

Mike Anderson, you are missing the point.

Please check here: http://shipilev.net/blog/2014/jmm-pragmatics/#_benchmarks, slide 77/100 "SC-DRF: Writes"

Alexey Shipilev: This reinforces the idea that data sharing is what you should avoid in the first place, not volatiles

Having ThreadLocal cache would eliminate "shared update" problem.

This ticket needs a better problem definition. That is: "I am doing ____" (with an example) that shows Reflector.getMethods() as the bottleneck

That is true.
My particular case was somehow resolved by development team.
I just thought some basic cache would make Clojure do the right thing by default and require less type specialization written manually.

Comment by Alex Miller [ 10/Dec/15 7:56 AM ]

I see a lot of "should" type statements in there. The whole point is that no change like this is going to go in until we know that there aren't impacts. But more importantly I'm not even going to mark it triaged until it's a good ticket that starts with a problem statement.

Comment by Mike Anderson [ 10/Dec/15 7:22 PM ]

Alex, what do you mean by "know there aren't impacts"? That seems an absurd position on the face of it, it is a perfectly acceptable trade-off to allow minor regressions in rare corner cases if you are improving the fast path / common case significantly.

Also, this definitely isn't a standard that is universally applied for changes to Clojure. Plenty of changes go into Clojure which cause performance regressions in other areas, you only need to look at Andy Fingerhut's excellent benchmarking efforts here to see that: https://jafingerhut.github.io/clojure-benchmarks-results/Clojure-expression-benchmark-graphs.html

Problem statement is IMHO obvious for anything performance related: "Performance of X is sub-optimal, which hurts users who are doing X." If you want a new ticket / changed description that says something like that then I'm happy to do it, but that seriously just feels like bureaucratic box ticking. Please consider this as constructive feedback on your contribution process.

What exactly (i.e. which benchmarks) do you need to see as a valid demonstration of improvement in performance-related issues like this?

Comment by Alex Miller [ 11/Dec/15 10:33 AM ]

Similar to my comments in CLJ-1866, the title of this ticket is "Reflector.getMethods should be cached". That is again a solution, not a problem. What I'm looking for is a title like "Repeated reflection in a loop is slow" and a description that starts with some example code demonstrating the problem. Without a good problem statement, I cannot triage this ticket. I may still consider the priority of the problem to be low enough that it's not worth triaging at this time - I'll withhold judgement though until the ticket is improved.

The fact that prior changes have had unexpected performance impacts only lends additional credence to my suggestion that this (performance-oriented) ticket should validate its claims. You have added code, which makes the "miss" path of this code slower than it was before. How much slower? It should make the "hit" path faster - how much faster? In typical code, how often do we encounter hit vs miss paths? My presumption is that the example will demonstrate a case where the hit path is common. These are the kinds of questions I, as a screener, must ask to evaluate any proposed solution.

Additionally, you are introducing concurrency concerns and some additional work is required to verify both correctness (the current patch has visibility issues) and that you have not introduced contention or memory issues. These are typical problems for any caching-related optimization and I could point you to any number of prior tickets that have wrestled with them.

Comment by Mike Anderson [ 11/Dec/15 9:13 PM ]

Thanks Alex for explaining your concerns.

I agree that a problem-oriented approach to patches is better, so I suggest the following:

  • We close both this issue and clj-1866
  • I create a separate problem-focused ticket for reflection performance
  • I'll benchmark the changes as whole for a number of different cases
  • You'll triage the patch on the assumption that we can demonstrate noticeable improvement in the common cases, all tests pass as before, and no major regressions occur in the corner cases (concurrent access, frequent cache misses etc.)

If you want a problem-oriented issue then I don't think it makes much sense to create separate tickets / patches for each "solution" (although some OSS projects choose to do it that way, they usually have have a much more streamlined process for minor changes / optimisations which probably doesn't suit the Clojure dev process)

Agreed?

Comment by Alex Miller [ 11/Dec/15 9:45 PM ]

As I said, we would prefer small focused tickets and patches, rather than one big patch.

I will reiterate that I'm not convinced doing any of this work makes sense if the scenario is one where a type hint would solve the problem.





[CLJ-1882] Use transients in merge-with Created: 11/Jan/16  Updated: 11/Jan/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Ghadi Shayban Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: performance, transient


 Description   

This ticket has been broken away from CLJ-1458 for tracking.






[CLJ-666] Add support for Big* numeric types to Reflector Created: 29/Oct/10  Updated: 27/Jul/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Chas Emerick Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: None

Attachments: Text File 0001-Add-Big-support-to-Reflector.patch     Text File 0001-Add-Big-support-to-Reflector-Updated.patch    
Patch: Code and Test

 Description   

This should work as expected, for example:

(Integer. 1N)

Probably for BigInt, BigInteger, and BigDecimal.

Method to look at is c.l.Reflector.paramArgTypeMatch, per Rich in irc.



 Comments   
Comment by Colin Jones [ 30/Mar/11 11:52 PM ]

Questions posed on the clojure-dev list around how this impacts bit-shift-left: http://groups.google.com/group/clojure-dev/browse_thread/thread/2191cbf0048d8ca6

Comment by Alexander Taggart [ 31/Mar/11 12:42 AM ]

Patch on CLJ-445 fixes this as well.

Comment by Colin Jones [ 27/Apr/11 4:41 PM ]

This patch fails a test around bit-shifting a BigInt: `(bit-shift-left 1N 10000)`. The reason is that the patch changes the dispatch of (BigInt, Long) from (Object, Object) to (long, int).

Clearly this can't be applied (unless another change makes it possible), but I'm putting it up as a start of the conversation.

Comment by Alexander Taggart [ 27/Apr/11 5:26 PM ]

My comment from the mailing list:

If the test breaks it likely means Numbers.shiftLeft(long,int) was
selected over Numbers.shiftLeft(Object,Object). Given that 1N is an
Object (one that can exceed the size of a long), the method selection
is incorrect, thus the patch is broken.


The suggestion of "simply" modifying paramArgTypeMatch is not sufficient since the mechanism for preferring one method over another lives in Compiler, and isn't smart enough to make these sorts of decisions.

Comment by Christopher Redinger [ 28/Apr/11 9:21 AM ]

Considering moving this out of Release.next - soliciting comments from Chas.

Comment by Chas Emerick [ 28/Apr/11 9:41 AM ]

I'm afraid I don't have any particular insight into the issues involved at this point. I ran into the problem originally noted a while back, and opened the ticket at Rich's suggestion. I'm sorry if the text of the ticket led anyone down unfruitful paths…

Comment by Luke VanderHart [ 29/Apr/11 10:01 AM ]

The issues relating to bitshift are moot since the decision was made that bit-shifts are only for 32/64 bit values.

Still a valid issue, but de-prioritized as per Rich.

Comment by Alex Ott [ 25/Jun/12 7:19 AM ]

Modified version of original patch

Comment by Andy Fingerhut [ 26/Jun/12 1:38 PM ]

Alex, would you mind attaching it with a unique file name? I know that JIRA lets us create multiple attachments with the same file name, and I know we can tell them apart by date and the account of the person who uploaded the attachment, but giving them the same name only seems to invite confusion.

Comment by Alex Ott [ 28/Jun/12 1:00 PM ]

Renamed updated patch to unique name





[CLJ-1096] Make destructuring emit direct keyword lookups Created: 29/Oct/12  Updated: 11/Jan/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4, Release 1.5, Release 1.6
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Christophe Grand Assignee: Christophe Grand
Resolution: Unresolved Votes: 4
Labels: destructuring, performance

Attachments: File desctructure-keyword-lookup.diff     File inline-get-keyword.diff    
Patch: Code
Approval: Triaged

 Description   

Currently associative destructuring emits calls to get. The attached patch modify desctruture to emit direct keyword lookups when possible.

Approved here https://groups.google.com/d/msg/clojure-dev/MaYcHQck8VA/nauMus4mzPgJ



 Comments   
Comment by Christophe Grand [ 04/Sep/13 3:40 AM ]

Rethinking about this patch now, it may be too specific: get's inline expansion should be modified when the key is a literal keyword.

Comment by Christophe Grand [ 04/Sep/13 3:41 AM ]

More generic patch (inline-get-keyword.diff): all get calls with literal keywords as keys are inlined to direct keyword lookup.

Comment by John Hume [ 19/May/14 1:14 PM ]

Is this only stalled out of lack of interest?

Comment by Andy Fingerhut [ 19/May/14 6:13 PM ]

There are currently about 50 tickets "triaged", i.e. marked for Rich to look at and decide whether they are things he is interested in seeing a patch for, and another 25 or so that were triaged and he has "vetted" them, and they are in various stages of having patches written for them, screened, etc. That doesn't mean anything for this ticket in particular – just wanted to make it clear that there are a bunch of other tickets that are getting some attention, and a bunch of others that are not.

What gets triaged depends somewhat upon how severe the issue appears. You can vote on the ticket, and try to persuade others to do so as well, if they think this would enhance the performance of some commonly-written types of Clojure code. You could also consider doing some benchmarking with & without these patches to see how much performance they can gain.





[CLJ-445] Method/Constructor resolution does not factor in widening conversion of primitive args Created: 29/Sep/10  Updated: 04/Mar/16

Status: In Progress
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: Backlog

Type: Enhancement Priority: Major
Reporter: Alexander Taggart Assignee: Unassigned
Resolution: Unresolved Votes: 3
Labels: None

Attachments: Text File clj-445-prim-conversion-update-2-patch.txt     Text File prim-conversion.patch     Text File prim-conversion-update-1.patch     Text File reorg-reflector.patch    
Approval: Vetted

 Description   

Problem:
When making java calls (or inlined functions), if both args and param are primitive, no widening conversion is used to locate the proper overloaded method/constructor.

Examples:

user=> (Integer. (byte 0))
java.lang.IllegalArgumentException: No matching ctor found for class java.lang.Integer (NO_SOURCE_FILE:0)
</code></pre>
The above occurs because there is no Integer(byte) constructor, though it should match on Integer(int).
<pre><code>user=> (bit-shift-left (byte 1) 1)
Reflection warning, NO_SOURCE_PATH:3 - call to shiftLeft can't be resolved.
2

In the above, a call is made via reflection to Numbers.shiftLeft(Object, Object) and its associated auto-boxing, instead of directly to the perfectly adequate Numbers.shiftLeft(long, int).

Workarounds:
Explicitly casting to the formal type.

Ancillary benefits of fixing:
It would also reduce the amount of method overloading, e.g., RT.intCast(char), intCast(byte), intCast(short), could all be removed, since such calls would pass to RT.intCast(int).



 Comments   
Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/445
Attachments:
fixbug445.diff - https://www.assembla.com/spaces/clojure/documents/b6gDSUZOur36b9eJe5cbCb/download/b6gDSUZOur36b9eJe5cbCb

Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

ataggart said: [file:b6gDSUZOur36b9eJe5cbCb]

Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

ataggart said: Also fixes #446.

Comment by Stuart Halloway [ 03/Dec/10 12:50 PM ]

The patch is causing a test failure

[java] Exception in thread "main" java.lang.IllegalArgumentException: 
     More than one matching method found: equiv, compiling:(clojure/pprint/cl_format.clj:428)

Can you take a look?

Comment by Stuart Halloway [ 28/Jan/11 12:30 PM ]

The failing test happens when trying to find the correct equiv for signature (Number, long). Is the compiler wrong to propose this signature, or is the resolution method wrong in not having an answer? (It thinks two signatures are tied: (Object, long) and (Number, Number).)

Exception in thread "main" java.lang.IllegalArgumentException: More than one matching method found: equiv, compiling:(clojure/pprint/cl_format.clj:428)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6062)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6050)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.access$100(Compiler.java:35)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5492)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2372)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3277)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6057)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2385)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2385)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$FnMethod.parse(Compiler.java:4667)
	at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3397)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6053)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.access$100(Compiler.java:35)
	at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:480)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler.eval(Compiler.java:6114)
	at clojure.lang.Compiler.load(Compiler.java:6545)
	at clojure.lang.RT.loadResourceScript(RT.java:340)
	at clojure.lang.RT.loadResourceScript(RT.java:331)
	at clojure.lang.RT.load(RT.java:409)
	at clojure.lang.RT.load(RT.java:381)
	at clojure.core$load$fn__1427.invoke(core.clj:5308)
	at clojure.core$load.doInvoke(core.clj:5307)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.pprint$eval3969.invoke(pprint.clj:46)
	at clojure.lang.Compiler.eval(Compiler.java:6110)
	at clojure.lang.Compiler.load(Compiler.java:6545)
	at clojure.lang.RT.loadResourceScript(RT.java:340)
	at clojure.lang.RT.loadResourceScript(RT.java:331)
	at clojure.lang.RT.load(RT.java:409)
	at clojure.lang.RT.load(RT.java:381)
	at clojure.core$load$fn__1427.invoke(core.clj:5308)
	at clojure.core$load.doInvoke(core.clj:5307)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.core$load_one.invoke(core.clj:5132)
	at clojure.core$load_lib.doInvoke(core.clj:5169)
	at clojure.lang.RestFn.applyTo(RestFn.java:143)
	at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:77)
	at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28)
	at clojure.core$apply.invoke(core.clj:602)
	at clojure.core$load_libs.doInvoke(core.clj:5203)
	at clojure.lang.RestFn.applyTo(RestFn.java:138)
	at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:77)
	at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28)
	at clojure.core$apply.invoke(core.clj:604)
	at clojure.core$use.doInvoke(core.clj:5283)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.main$repl.doInvoke(main.clj:196)
	at clojure.lang.RestFn.invoke(RestFn.java:422)
	at clojure.main$repl_opt.invoke(main.clj:267)
	at clojure.main$main.doInvoke(main.clj:362)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.lang.Var.invoke(Var.java:401)
	at clojure.lang.AFn.applyToHelper(AFn.java:163)
	at clojure.lang.Var.applyTo(Var.java:518)
	at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: More than one matching method found: equiv
	at clojure.lang.Reflector.getMatchingParams(Reflector.java:639)
	at clojure.lang.Reflector.getMatchingParams(Reflector.java:578)
	at clojure.lang.Reflector.getMatchingMethod(Reflector.java:569)
	at clojure.lang.Compiler$StaticMethodExpr.<init>(Compiler.java:1439)
	at clojure.lang.Compiler$HostExpr$Parser.parse(Compiler.java:896)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	... 115 more
Comment by Alexander Taggart [ 08/Feb/11 6:27 PM ]

In working on implementing support for vararg methods, I found a number of flaws with the previous solutions. Please disregard them.

I've attached a single patch (reflector-compiler-numbers.diff) which is a rather substantial overhaul of the Reflector code, with some enhancements to the Compiler and Numbers code.

The patch notes:

  • Moved reflection functionality from Compiler to Reflector.
  • Reflector supports finding overloaded methods by widening conversion, boxing conversion, and casting.
  • During compilation Reflector attempts to find best wildcard match.
  • Reflector refers to *unchecked-math* when reflectively invoking methods and constructors.
  • Both Reflector and Compiler support variable arity java methods and constructor; backwards compatible with passing an array or nil in the vararg slot.
  • Added more informative error messages to Reflector.
  • Added tests to clojure.test-clojure.reflector.
  • Altered overloaded functions of clojure.lang.Numbers to service Object/double/long params; fixes some ambiguity issues and avoids unnecessary boxing in some cases.
  • Patch closes issues 380, 440, 445, 666, and possibly 259 (not enough detail provided).
Comment by Alexander Taggart [ 10/Feb/11 7:35 PM ]

Updated patch to fix a bug where a concrete class with multiple identical Methods (e.g., one from an interface, another from an abstract class) would result in ambiguity. Now resolved by arbitrary selection (this is what the original code did as well albeit not explicitly).

Comment by Alexander Taggart [ 25/Feb/11 9:29 PM ]

Updated patch to work with latest master branch.

Comment by Stuart Halloway [ 06/Mar/11 1:54 PM ]

patch appears to be missing test file clojure/test_clojure/reflector.clj.

Comment by Alexander Taggart [ 06/Mar/11 2:39 PM ]

Bit by git.

Patch corrected to contain clojure.test-clojure.reflector.

Comment by Stuart Halloway [ 11/Mar/11 10:30 AM ]

Rich: I verified that the patch applied but reviewed only briefly, knowing you will want to go over this one closely.

Comment by Stuart Halloway [ 11/Mar/11 10:55 AM ]

After applying this patch, I am getting method missing errors:

java.lang.NoSuchMethodError: clojure.lang.Numbers.lt(JLjava/lang/Object;)

but only when using compiled code, e.g. the same code works in the REPL and then fails after compilation. Haven't been able to isolate an example that I can share here yet, but hoping this will cause someone to have an "a, hah" moment...

Comment by Alexander Taggart [ 02/Apr/11 12:55 PM ]

The patch now contains only the minimal changes needed to support widening conversion. Cleanup of Numbers overloads, etc., can wait until this patch gets applied. The vararg support is in a separate patch on CLJ-440.

Comment by Christopher Redinger [ 15/Apr/11 12:50 PM ]

Please test patch

Comment by Christopher Redinger [ 21/Apr/11 11:02 AM ]

FYI: Patch applies cleanly on master and all tests pass as of 4/21 (2011)

Comment by Christopher Redinger [ 22/Apr/11 9:57 AM ]

This work is too big to take into the 1.3 beta right now. We'll revisit for a future release.

Comment by Alexander Taggart [ 28/Apr/11 1:19 PM ]

To better facilitate understanding of the changes, I've broken them up into two patches, each with a number of isolable, incremental commits:

reorg-reflector.patch: Moves the reflection/invocation code from Compiler to Reflector, and eliminates redundant code. The result is a single code base for resolving methods/constructors, which will allow for altering that mechanism without excess external coordination. This contains no behaviour changes.

prim-conversion.patch: Depends on the above. Alters the method/constructor resolution process:

  • more consistent with java resolution, especially when calling pre-1.5 APIs
  • adds support for widening conversion of primitive numerics of the same category (this is more strict than java, and more clojuresque)
  • adds support for wildcard matches at compile-time (i.e., you don't need to type-hint every arg to avoid reflection).

This also provides a base to add further features, e.g., CLJ-666.

Comment by Alexander Taggart [ 29/Apr/11 3:01 PM ]

It's documented in situ, but here are the conversion rules that the reflector uses to find methods:

  1. By Type:
    • object to ancestor type
    • primitive to a wider primitive of the same numeric category (new)
  2. Boxing:
    • boxed number to its primitive
    • boxed number to a wider primitive of the same numeric category (new for Short and Byte args)
    • primitive to its boxed value
    • primitive to Number or Object (new)
  3. Casting:
    • long to int
    • double to float
Comment by Alexander Taggart [ 10/May/11 3:13 PM ]

prim-conversion-update-1.patch applies to current master.

Comment by Alexander Taggart [ 11/May/11 2:15 PM ]

Created CLJ-792 for the reflector reorg.

Comment by Stuart Sierra [ 17/Feb/12 2:29 PM ]

prim-conversion-update-1.patch does not apply as of f5bcf64.

Is CLJ-792 now a prerequisite of this ticket?

Comment by Alexander Taggart [ 17/Feb/12 3:15 PM ]

Yes, after the original patch was deemed "too big".

After this much time with no action from TPTB, feel free to kill both tickets.

Comment by Andy Fingerhut [ 20/Feb/12 2:04 PM ]

Again, not sure if this is any help, but I've tested starting from Clojure head as of Feb 20, 2012, applying clj-792-reorg-reflector-patch2.txt attached to CLJ-792, and then applying clj-445-prim-conversion-update-2-patch.txt attached to this ticket, and the result compiles and passes all but 2 tests. I don't know whether those failures are easy to fix or not, or whether issues may have been introduced with these patches.

Comment by Nicola Mometto [ 30/Jan/15 7:25 AM ]

As of 1.7.0-alpha5 the two examples in the ticket description run without exceptions/reflection-warnings

user=> (set! *warn-on-reflection* true)
true
user=> (bit-shift-left (byte 1) 1)
2
user=> (Integer. (byte 0))
0
Comment by Petr Yanovich [ 04/Mar/16 7:17 AM ]

Hi!

(Integer. (Long. 1))
#=> 1
(Long. (Integer. 1))
#=> Exception

https://github.com/clojure/clojure/pull/59





[CLJ-1530] Make foo/bar/baz unreadable Created: 22/Sep/14  Updated: 31/Mar/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reader

Attachments: Text File 0001-fix-LispReader-and-EdnReader-so-that-foo-bar-baz-is-.patch    
Patch: Code and Test
Approval: Triaged

 Description   

Currently keywords and symbols containing more than one slash are disallowed by the spec, but allowed by the readers.
This trivial patch makes them unreadable by the readers too.

Pre:

user=> :foo/bar/baz
:foo/bar/baz

Post:

user=> :foo/bar/baz
RuntimeException Invalid token: :foo/bar/baz  clojure.lang.Util.runtimeException (Util.java:221)


 Comments   
Comment by Andy Fingerhut [ 22/Sep/14 12:14 PM ]

Perhaps overlap with CLJ-1527 ?

Comment by Thomas Engelschmidt [ 28/Oct/14 4:36 AM ]

Please notice that keywords with more than one slash has a different hashcode across clojure version 1.5 and 1.6

This creates a problem when using a datomic version that works with clojure 1.5 under clojure 1.6 and the schema have one or more keys with more than one slash.

Comment by Chris Zheng [ 30/Mar/16 8:41 AM ]

Please reconsider this `fix` for the following reasons:

Please see discussion on this topic below:

dm3 [5:04 PM]
Is there a reason why `(read-string "a/b/c")` is OK, while `(clojure.tools.reader/read-string "a/b/c")` fails with `Invalid token`?

hiredman [5:04 PM]
there is a ticket to fix read-string

dm3 [5:05 PM]
so the correct behaviour is to fail?

hiredman [5:05 PM]
http://dev.clojure.org/jira/browse/CLJ-1530

dm3 [5:06 PM]
thanks, seems like a breaking change :simple_smile:

hiredman [5:07 PM]
the docs have precluded symbols like a/b/c for some time, and the behavior of how those unspecified symbols were read apparently changed at some point

lucas [5:09 PM]
joined #clojure

zcaudate [5:16 PM]
@hiredman: seriously. I’m really peeved about that because I’ve been using `:a/b/c` keywords for a while… even wrote a whole freaking library to deal with that http://docs.caudate.me/hara/hara-string.html#api---path (edited)

[5:16]
and now they are taking it out

[5:18]
i’m of the opinion that the `::foo/baz` keywords should be taken out first

[5:20]
```user=> (require '[clojure.walk :as walk])
nil
user=> ::walk/hello
:clojure.walk/hello
```

[5:20]
that causes way more problems

[5:20]
especially with analysers

[5:22]
https://github.com/jonase/kibit/issues/14

GitHub
Kibit breaks on namespace qualified keywords · Issue #14 · jonase/kibit · GitHub
If the code contains namespace qualified keywords with aliases, Kibit errors out with a Invalid token exception. The following code demonstrates the problem - ;;; foo.clj (ns foo) ;;; bar.clj (n...

[5:25]
@dm3 if there’s really a problem, you can patch it:

[5:25]
https://github.com/helpshift/hydrox/blob/master/lein/src/leiningen/hydrox/setup.clj

GitHub
helpshift/hydrox
hydrox - Dive deeper into your code

dm3 [5:31 PM]
yeah, would have to patch cljs.tools.reader too unfortunately :confused:

[5:31]
think I'll just work around that

bronsa [5:36 PM]
@zcaudate: `::foo/bar` style keywords are in by design and not going anywhere, `:foo/bar/baz` have always been invalid by the spec and undefined behaviour (edited)

[5:37]
@dm3: is changing undefined behaviour a breaking change? :simple_smile:

dm3 [5:37 PM]
breaking as in breaking people's code :simple_smile:

[5:37]
e.g. zcaudate

bronsa [5:38 PM]
that code is already broken if it's using invalid clojure. It's just accidentaly working

dm3 [5:39 PM]
I'm looking from a pragmatic perspective. Theoretically you're right :simple_smile:

[5:40]
and I'm not judging either

bronsa [5:40 PM]
pragmatically, `:foo/bar/baz` is a bug waiting to happen. what does `(namespace :foo/bar/baz)` return?

dm3 [5:40 PM]
whatever it returns currently?

[5:41]
I mean it's kind of defined by the implementation

sveri [5:41 PM]
@dm3 @bronsa I wouldnt even agree that you are theoretically right. As soon as enough people adapted the broken code it falls under something like a common law that was accepted by both parties for a long enough time.

bronsa [5:42 PM]
what about `namespace` on `(keyword "foo/bar" "baz")` and `(keyword "foo" "bar/baz")`

dm3 [5:43 PM]
I agree that currently implemented semantics are messy

[5:43]
but my point was that it's still a breaking change

[5:43]
not that it's a "bad" change

[5:43]
that's a judgement

bronsa [5:43 PM]
@sveri: I would agree with you, as long as the undefined behaviour we accept as defined doesn't cause impossible to fix semantics.

[5:44]
that's why for example, the patch that made symbols starting with numbers illegal was rolled back

[5:45]
it broke existing code, it didn't cause weird semantics so it was rolled back. not the case with `:foo/bar/baz`

[5:45]
@dm3: you could make the point that fixing any bug is a breaking change then – people might be relying on that bug.

dm3 [5:46 PM]
yep, I guess what matters is how obvious the incorrect behaviour is and how many people rely on it

bronsa [5:46 PM]
if the doc explicitely says "you can use ​one​ `/` inside a symbol", then if you're using more than one you're writing invalid clojure and you should expect it to maybe break (edited)

dm3 [5:47 PM]
I really haven't even thought about multiple slashes (nor noticed the docs) in a symbol in ~3 years of using Clojure

[5:47]
my initial thought (today) was that it was permitted

[5:47]
and the namespace would be the first segment before the first slash (edited)

bronsa [5:51 PM]
well, that doesn't make much sense though. `/` in clojure means `namespace separator`. if I see `FOO/BAR`, no matter what `FOO` and `BAR` are, I know that `FOO` is the namespace, and `BAR` is the name. if you want to express paths with keywords as in @zcaudate's lib, you should use a different separator in your keywords that doesn't have a special meaning in clojure, like `.` (i.e. `:foo/bar/baz` -> `:foo.bar.baz` or `:foo/bar.baz`) (edited)

dm3 [5:51 PM]
I do not want to argue semantics. Just sharing one point of view

bronsa [5:52 PM]
and my point is that pragmatic point of views (especially when they go against the current doc) should only be considered if the semantics they imply are clear and unambiguous

sveri [5:53 PM]
@bronsa: Nice explanation, thank you :simple_smile:

dm3 [5:53 PM]
yep :simple_smile:

[5:54]
I agree to that, as you have to make decisions in the end

zcaudate [9:07 PM]
@bronsa: written form of communication has a way of making things more serious than they seem

[9:08]
honestly… i knew it was coming since 1.6 when the edn reader started breaking my code

[9:09]
it’s probably more my fault for not communicating this earlier but oh well.. we all have to roll with the times

bronsa [9:09 PM]
@zcaudate: yeah no worries, I was just using your lib as an example since you brought that up

zcaudate [9:10 PM]
having said that, you can imagine my disappointment because I had designed an entire query semantic based on the keyword `:foo/bar/baz` feature (now bug) (edited)

[9:11]
http://docs.caudate.me/adi/adi-walkthrough.html#querying

[9:11]
you noticed I didn’t use `(adi/select ds {:student/classes/teacher/name "Mr. Blair"}})`

[9:12]
in my docs because the tests started breaking

jstew [9:12 PM]
@zcaudate: You put out so much quality stuff that I wonder if you ever sleep!
1

bronsa [9:12 PM]
@zcaudate: luckly the fix should be easy :simple_smile: just replace `/` with `.`

zcaudate [9:12 PM]
no!

[9:13]
see the problem is… datomic has things like `account.type/user`

[9:13]
and so I would have to do the cljs thing `account.type$user`

bronsa [9:13 PM]
(that's some high quality documentation btw, good job)

zcaudate [9:14 PM]
@bronsa: hahaha thanks… so maybe you can push the fix to 1.10

[9:14]
that way I can get a few more months left

[9:15]
like it’s not a big deal… but I thought that there is a parallel between the path structure of the `/` calls and the nesting of maps

[9:16]
and so there is an equivalence to `{:student {:classes {:teacher {:name '(?fulltext "Blair")}`

[9:17]
and `{:student/classes/teacher/name "Mr. Blair"}`

[9:17]
which is prettier in my opinion

bronsa [9:17 PM]
@zcaudate: sorry if that wasn't clear, but I don't actually have any control over when or what gets into clojure or not, I'm just a contributor :simple_smile: so there are chances that the clojure/core team will take a different decision and actually decline that ticket (I would be really disappointed if that was the case though!). If that will happenI will obviously make a change to `tools.reader` to allow them aswell, (edited)

zcaudate [9:18 PM]
@bronsa: damn.

[9:19]
well… maybe you can highlight this fact

[9:19]
and also if the fix is made, a fix to `(keyword "foo/bar/baz")` will also be needed (edited)

bronsa [9:20 PM]
don't think that'll ever be done. validating inputs to `keyword`/`symbol` etc has been asked/discussed tons of times and repeatedly declined for performance reasons

zcaudate [9:20 PM]
so that’s a matter of consistency.

bronsa [9:20 PM]
(not that I agree with that decision, but it seems like Rich isn't going ot change his mind on that)

[9:21]
@zcaudate: there's a difference between what a symbol/keyword can be at runtime, and what a valid read-time symbol/keyword is

zcaudate [9:21 PM]
and also, it means I can setup a reader macro #k foo/bar/baz and get the same effect

[9:22]
like it’s stupidly ugly but i believe it will work

bronsa [9:23 PM]
but the ambiguity of what to do with `namespace` and `name` still remains so dunno

[9:23]
@zcaudate: that wouldn't work either way, if http://dev.clojure.org/jira/browse/CLJ-1530 gets accepted neither `:foo/bar/baz` ​nor​ `foo/bar/baz` will be valid anymore

[9:24]
@zcaudate: btw I'd suggest you log your issues with that ticket in a comment there if you feel strongly against it

new messages
[9:25]
I ​suspect​ that the response will be "you should use a delimiter that doesn't have a special meaning in clojure", but I might be completely wrong (I find the core team doesn't agree with my opinions quite frequently ) especially if you point out that your library will break. (edited)

zcaudate [9:30 PM]
@bronsa: thanks for the heads up. I’ll leave a comment and add a prayer for the bdfl

Comment by Alex Miller [ 30/Mar/16 8:55 AM ]

Chris -

  • (keyword "foo/bar/baz") will still be fine. Programmatic keywords can be created for any string - this is intentionally much broader than what the reader supports as a literal in code and it's a feature that's widely used. At some future point, there may be an escaping mechanism for symbols or keywords with characters outside the spec such that the reader could read them as well, but that's outside the scope of this.
  • Your api is using illegal keywords according to http://clojure.org/reference/reader and you should not expect them to work. I think you should change your library.
Comment by Chris Zheng [ 30/Mar/16 6:15 PM ]

Alex

  • I wouldn't necessarily call it `illegal` as the current behavior in the edn.reader was added in 1.6 without warning.
  • Also, if (keyword "foo/bar/baz") is allowed to exist, then there still would be the indeterminate namespace/name problem that @bronsa highlighted. I would argue for consistency and if :foo/bar/baz is illegal in the reader, then it should be illegal everywhere
  • My library should be fine... but users of the library may have to change their queries
Comment by Alex Miller [ 30/Mar/16 7:00 PM ]

The reader page clearly states "'/' has special meaning, it can be used once in the middle of a symbol to separate the namespace from the name" and keywords are "like symbols". This has been on the reader page since the oldest version I can find in the internet archive (July 2008). edn (despite its similarities) is a separate thing than Clojure, and irrelevant.

The 2-arity form of keyword can be used without ambiguity: (keyword nil "foo/bar/baz"). The 1-arity form will split based on the first / found (in this example into "foo" and "bar/baz"). I see no reason that would need to change.

Comment by Chris Zheng [ 31/Mar/16 8:58 AM ]

I disagree on the "specialness" of `/` in keywords, especially if it is allowed as a string.

This leads to another problem in the ambiguity of output:

user=> (keyword "foo" "bar/baz")
:foo/bar/baz

user=> (keyword nil "foo/bar/baz")
:foo/bar/baz

Unless the output is displayed as :foo//bar/baz, it is unclear where the namespace is and the concept of `code is data` will be diminished if the output cannot be read back as data.

There is also the case for symbol:
user=> (symbol "foo/bar/baz")
foo/bar/baz

well... at least all the examples listed are all consistently "illegal"

Anyways, even if the docs had not explicitly stated such, :foo/bar/baz has existed since the beginning of clojure and personally, it seems to be more string-like than symbol-like. Ironically, I'm pretty sure that I got the idea of using multiple slashes in keywords from reading the datomic documentation from back when I started work on adi.

Ultimately, the decision is not mine to make and I do value the guidance of clojure team over the development of the language. I do however, hope that my points for keeping things as they are can be recognised and be taken into consideration.

Comment by Chris Zheng [ 31/Mar/16 9:23 AM ]

I'll quote Rich https://www.youtube.com/watch?v=P76Vbsk_3J0 @ 5:10

"Many of the things you consider to be problems (with lisp) are features... down the line..."





[CLJ-1874] Var redefinition breaks in AOT-compiled code Created: 05/Jan/16  Updated: 18/Feb/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Defect Priority: Major
Reporter: William Parker Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: aot, compiler

Attachments: Text File 0001-CLJ-1874-ensure-vars-get-interned-when-AOT-compiled.patch    
Patch: Code

 Description   

This is basically a copy of my post from https://groups.google.com/forum/#!topic/clojure/Ozt5HQyM36I on the mailing list. Based on the replies there I'm not sure whether this should be logged as an enhancement or a defect. Please change the designation to whatever is appropriate.

I have found what appears to be a bug in AOT-compiled Clojure when ns-unmap is used; the root cause of this probably impacts other code that redefines Vars as well. I have the following reduced case:

(ns unmap-test.core)

(def a :test-1)

(ns-unmap 'unmap-test.core 'a)

(def a :test-2)

It turns out that a is not resolvable when this namespace is loaded. When I looked at the compiled bytecode,
it appears that the following operations occur:

1. A call to RT.var withe 'unmap-test.core and 'a returns a Var, which is bound to a constant.
This var is added to the namespaces's mapping during this call.
2. Same as 1.
3. The var from 1 is bound to :test-1.
4. ns-unmap is called.
5. The var from 2 is bound to :test-2.

Disclaimer: This is the first time I have had occasion to look directly at bytecode and I could be missing something.

The basic problem here is that the var is accessible from the load method, but when step 5 executes the var is no longer
accessible from the namespace mappings. Thus, the root of the Var is set to :test-2, but that Var is not mapped from the namespace.
This works when there is no AOT compilation, as well as when I use

(ns unmap-test.core)

(def a :test-1)

(ns-unmap 'unmap-test.core 'a)

(intern 'unmap-test.core 'a :test-2)

I realize that creating defs, unmapping them, and then recreating them is generally poor practice in Clojure.
We have an odd case in that we need to have an interface and a Var of the same name in the same namespace. Simply
doing definterface and then def causes a compilation failure:

user=> (definterface abc)
user.abc
user=> (def abc 1)
CompilerException java.lang.RuntimeException: Expecting var, but abc is mapped to interface user.abc, compiling/private/var/folders/3m/tvc28b5d7p50v5_8q5ntj0pmflbdh9/T/form-init4734176956271823921.clj:1:1)

Without going into too much detail, this is basically a hack to allow us to refactor our internal framework code
without immediately changing a very large amount of downstream consumer code. We get rid of the usage of the interface during macroexpansion,
but it still needs to exist on the classpath so it can be imported by downstream namespaces.
There are a number of other ways to accomplish this, so it isn't a particularly big problem for us, but I thought the issue was worth raising.
This was just the first thing I tried and I was surprised when it didn't work.

Note that I used the 1.8.0 RC4 version of Clojure in my sample project, but I had the same behavior on 1.7.0.

Relevant links:

1. Bytecode for the load method of the init class: https://gist.github.com/WilliamParker/d8ef4c0555a30135f35a
2. Bytecode for the init0 method: https://gist.github.com/WilliamParker/dc606ad086670915efd9
3. Decompiled Java code for the init class. Note that this does not completely line up with the bytecode as far as I can tell,
but it is a quicker way to get a general idea of what is happening than the bytecode.
https://gist.github.com/WilliamParker/4cc47939f613d4595d94
4. A simple project containing the code above: https://github.com/WilliamParker/unmap-test
Note that if you try it without AOT compilation the target folder with any previously compiled classes should be removed.



 Comments   
Comment by Nicola Mometto [ 05/Jan/16 9:44 AM ]

The issue is similar to the one in CLJ-1604, the proposed patch extends that fix to all vars rather than just for clojure.core ones.

Comment by Kevin Downey [ 17/Feb/16 10:21 AM ]

was this fixed by clj-1604?

Comment by Nicola Mometto [ 18/Feb/16 8:38 AM ]

No, CLJ-1604 only deals with clojure.core Vars, the patch attached to this ticket is an extension on top of the patch committed for CLJ-1604 that deals with other namespaces





[CLJ-1996] clojure.spec stubs don't cooperate with clojure.spec.test/check Created: 31/Jul/16  Updated: 31/Jul/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Gary Fredericks Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

This is just like CLJ-1949, but for stubs instead of higher-order-function arguments.

The solution is more difficult, though, since cst/check and cst/instrument can be called/used seperately.

My only idea is to have a dynamic var where the two can coordinate. Stubs would use gen/generate when not called during testing, but in the context of a call to cst/check the dynamic var would contain an alternate implementation that works similarly to the patch in CLJ-1949.

I'd be happy to prepare a patch with that implementation (or any other) if desired.






[CLJ-1997] Macros cannot reliably detect usage of locals Created: 02/Aug/16  Updated: 02/Aug/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Gary Fredericks Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: macro


 Description   

Problem

The motivating problem is the implementation of gen/let in test.check (see also TCHECK-98).

A common usage of gen/let might look something like this:

(gen/let [a gen-a
          b gen-b]
  (f a b))

The crucial characteristic of this code is that the generator for b does not depend on the value a (though in general it could). Because of this independence, the ideal expansion is:

(gen/fmap 
  (fn [[a b]] (f a b)) 
  (gen/tuple gen-a gen-b))

However, because gen/let cannot, in general, tell whether or not the expression for the generator for b depends on a, it needs to fallback to a more general expansion:

(gen/fmap
  (fn [[a b]] (f a b))
  (gen/bind 
    gen-a
    (fn [a]
      (gen/tuple (gen/return a) gen-b))))

Using gen/bind greatly reduces shrinking power, and so it's best to avoid it when possible.

A knowledgeable user could get around this by using gen/tuple explicitly, e.g.:

(gen/let [[a b] (gen/tuple gen-a gen-b)]
  (f a b))

But I think most users would prefer not to have to think about these things.

Possible Solutions

tools.analyzer

tools.analyzer is probably adequate, but is a large dependency for a library.

a subset of tools.analyzer

Nicola has mentioned the idea of carving out some subset of the analyzer that would be sufficient for this case, and that might be the best option.

a mechanism for macroexpanding a macro body

I believe if there were a robust mechanism for a macro to fully macroexpand an expression that this problem would be easier (clojure.core/macroexpand and friends have a few known incorrectnesses) – a simple tree-seq over the expanded expression could prove that a local is not used (though a naive approach might falsely conclude that a local *is* used, which might be an acceptable compromise for the test.check case, and otherwise a robust code walker should not be difficult to implement on expanded code).

I believe zach's riddley library does something like this, and depending on riddley would probably be the best option for a non-contrib library, but is not an acceptable dependency for a contrib library.






[CLJ-2011] clojure.walk.macroexpand-all will not properly expand macros that depend on &env Created: 23/Aug/16  Updated: 23/Aug/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.8, Release 1.9
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Collin Bell Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: macro, walk
Environment:

MacOSX, Clojure 1.9.0-alpha10, Java 1.8.0_45, CIDER 0.13.0snapshot (package: 20160602.809), nREPL 0.2.12



 Description   

(clojure.walk/macroexpand-all '(defn foo [a] (go [] a)))

Unhandled clojure.lang.ExceptionInfo
Could not resolve var: a
{:var a}

This is because go depends on &env and macroexpand-all does not handle &env.

The reason this issue is important is because it breaks the cider debugger for async.






[CLJ-1880] IKVReduce impl for records Created: 09/Jan/16  Updated: 11/Jan/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Ghadi Shayban Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: defrecord

Attachments: Text File CLJ-1880.patch    
Approval: Triaged

 Description   

Records don't implement IKVReduce, which could help with efficient merging (CLJ-1458)



 Comments   
Comment by Ghadi Shayban [ 11/Jan/16 2:49 PM ]

simple implementation attached





[CLJ-2090] Improve clojure.core/distinct perf by using transient set Created: 23/Dec/16  Updated: 04/Jan/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Nikita Prokopov Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: performance, transducers, transient

Attachments: Text File clj-2090-use-transient-set-in-distinct-2.patch    
Patch: Code
Approval: Triaged

 Description   

Current implementation of clojure.core/distinct uses persistent set. This patch improves performance of lazy arity by ~25%-30% and transducer by ~40%-50% by using transient set instead.

10 elements
(doall (distinct coll)) 	 5.773439 µs => 4.179092 µs (-27%)
(into [] (distinct) coll) 	 3.238236 µs => 1.943254 µs (-39%)

100 elements
(doall (distinct coll)) 	 67.725764 µs => 42.129993 µs (-37%)
(into [] (distinct) coll) 	 35.702741 µs => 16.495947 µs (-53%)

1000 elements
(doall (distinct coll)) 	 540.652739 µs => 399.053873 µs (-26%)
(into [] (distinct) coll) 	 301.423077 µs => 164.025500 µs (-45%)

10000 elements
(doall (distinct coll)) 	 3.439137 ms => 3.058872 ms (-11%)
(into [] (distinct) coll) 	 1.437390 ms => 848.277178 µs (-40%)

Benchmarking code: https://gist.github.com/tonsky/97dfe1f9c48eccafc983a49c7042fb21



 Comments   
Comment by Alex Miller [ 23/Dec/16 8:52 AM ]

You can't remove the volatile - you still need that for safe publication in multi threaded transducing contexts.

Comment by Nikita Prokopov [ 23/Dec/16 11:50 AM ]

Alex Miller How do you mean?

  • I don’t update seen link because transient set can be mutated in-place
  • Are transducers meant to be used from multiple threads? Because even existing implementation clearly has race condition. I imagine fixing that would be costly (we’ll need a synchronized section), so maybe it should be a specialized transducer that you use only when needed?
Comment by Alex Miller [ 23/Dec/16 12:26 PM ]

Transient sets can NOT be mutated in place - you must use the return value.

Yes, transducers are used from multiple threads in (for example) transducer chans in core.async go blocks.

Comment by Alex Miller [ 23/Dec/16 12:28 PM ]

I should also say transducers are not expected to be used from more than one thread at a time, so there are no race problems. But being used from multiple threads over time requires proper safe publication.

Comment by Nikita Prokopov [ 24/Dec/16 3:07 AM ]

But being used from multiple threads over time requires proper safe publication.

Does that imply that no transients could be used in transducers (because underlying arrays on which transient impl is based are mutated in place, so different threads could potentially see different states of transient object)?

Does that also mean that partition-by and partition-all should be fixed (they use java.util.ArrayList which, being array of references, has no safe publication semantics)?

Transient sets can NOT be mutated in place - you must use the return value.

I was thinking that clojure/core.clj and clojure.lang.ATransientSet.java are both part of Clojure internals, colocated, so can share a little bit of internal knowledge about each other. It seems safe to do that, because that knowledge does not leak outside, and, if at any point impl of ATransientSet would change, core.clj could be updated accordingly in the same release. I wouldn’t do that in any third-party library, of course.

Comment by Alex Miller [ 24/Dec/16 9:13 AM ]

Does that imply that no transients could be used in transducers (because underlying arrays on which transient impl is based are mutated in place, so different threads could potentially see different states of transient object)?

Transients require only that they are asked by no more than a single thread at a time and so are safe to use in a transducer. However, they should guarantee safe publication. core.async channels already do this as an artifact of their implementation, but other transducing contexts may not.

Transients should NEVER be used as "mutate in place", regardless of concurrency. While they will appear to "work" in some circumstances, this is never correct (eventually an update operation will return a new instance and if you are mutating in place, your data will then be missing). This is discussed and correct examples are shown at http://clojure.org/reference/transients.

Does that also mean that partition-by and partition-all should be fixed (they use java.util.ArrayList which, being array of references, has no safe publication semantics)?

That's something Rich and I are discussing but, probably.

Comment by Nikita Prokopov [ 24/Dec/16 12:56 PM ]

Alex Miller Here’s quick test that shows that changes to transient set (which is nothing more but a wrapper around transient map) made in one thread are not always visible from another thread.

https://gist.github.com/tonsky/62a7ec6d539fc013186bee2df0812cf6

That means that if we try to use transients for e.g. distinct it will miss duplicate items

Comment by Nikita Prokopov [ 24/Dec/16 1:02 PM ]

Removed transients from transducer arity of distincts because transducers might be accessed from multiple threads

Comment by Nikita Prokopov [ 24/Dec/16 1:12 PM ]

Maybe that doc http://clojure.org/reference/transients should be updated re: transients are not safe to use from multiple threads because changes made by one thread are not necessarily visible to another. Even if they don’t compete

Comment by Alex Miller [ 31/Dec/16 12:54 PM ]

I would say that test is demonstrating a bug in transient sets/maps and you should file a ticket for that as it's a lot more important than this enhancement.

distinct should be able to use transients in both the transducer and lazy seq impls. The issue with contains? not working on transients is actually a separate ticket - http://dev.clojure.org/jira/browse/CLJ-700 that will likely require some class hierarchy rearrangement. I don't think we would take this change until that is fixed (so that you can avoid relying on the class and Java method variants).

Comment by Nikita Prokopov [ 04/Jan/17 11:47 AM ]

I have to admit my test was demonstrating something else: there were no proper thread isolation. So it was a concurrency issue, not “safe publication” issue. My current understanding is this:

Transients require thread isolation. Use of a particular transient instance should be controlled either by using it in an single-threaded scope, or in a framework that enforces this.

That guarantee implicitly presumes that there’s happens-before relation between transient usage from multiple threads. There’s no other way to define “only one thread is in this section at a time”.

That, in turn, means that all writes that happened in thread 1 are visible in thread 2, regardless to volatility of the variables involved. In fact, we can remove all volatiles from transients implementation and probably make them faster, because, by asking “no more than one thread at a time” we enforce users to establish happens-before between sections, and that would give us all the safe publication guarantees we need.

Is my understanding correct? Am I missing something?

Comment by Nikita Prokopov [ 04/Jan/17 11:55 AM ]

Also, long-living transients (e.g. in a transducers associated with a queue, for example) will hold a reference to a thread that created them. Is that a bad thing? Should we switch to boolean flag instead?





[CLJ-1865] Direct linking doesn't work on recursive calls Created: 08/Dec/15  Updated: 06/Jan/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.8
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: compiler, directlinking


 Description   

It looks like self-recursive calls aren't optimized by direct linking, but if we redefine the same function twice, the Compiler is tricked into thinking that the call is not recursive and (rightfully) optimizes it into an invokeStatic.

I haven't investigated the cause but I suspect (and I might be wrong) it has to do with :arglist metadata potentially having different values when the Var is undefined vs when it's already bound.

[~]> cat test.clj
(ns test)

(defn a [x]
  (a x))
[~]> clj
Clojure 1.8.0-master-SNAPSHOT
user=> (compile 'test)
test
user=> ^D
[~]> cd classes
[~/classes]> javap -c test\$a
Compiled from "test.clj"
public final class test$a extends clojure.lang.AFunction {
  public static final clojure.lang.Var const__0;

  public static {};
    Code:
       0: ldc           #11                 // String test
       2: ldc           #13                 // String a
       4: invokestatic  #19                 // Method clojure/lang/RT.var:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Var;
       7: checkcast     #21                 // class clojure/lang/Var
      10: putstatic     #23                 // Field const__0:Lclojure/lang/Var;
      13: return

  public test$a();
    Code:
       0: aload_0
       1: invokespecial #26                 // Method clojure/lang/AFunction."<init>":()V
       4: return

  public static java.lang.Object invokeStatic(java.lang.Object);
    Code:
       0: getstatic     #23                 // Field const__0:Lclojure/lang/Var;
       3: invokevirtual #32                 // Method clojure/lang/Var.getRawRoot:()Ljava/lang/Object;
       6: checkcast     #34                 // class clojure/lang/IFn
       9: aload_0
      10: aconst_null
      11: astore_0
      12: invokeinterface #37,  2           // InterfaceMethod clojure/lang/IFn.invoke:(Ljava/lang/Object;)Ljava/lang/Object;
      17: areturn

  public java.lang.Object invoke(java.lang.Object);
    Code:
       0: aload_1
       1: aconst_null
       2: astore_1
       3: invokestatic  #41                 // Method invokeStatic:(Ljava/lang/Object;)Ljava/lang/Object;
       6: areturn
}

Redefining the same function twice makes it work.

[~]> cat test.clj
(ns test)

(defn a [x]
  (a x))

(defn a [x]
  (a x))
[~]> clj
Clojure 1.8.0-master-SNAPSHOT
user=> (compile 'test)
test
user=> ^D
[~]> cd classes
[~/classes]> javap -c test\$a
Compiled from "test.clj"
public final class test$a extends clojure.lang.AFunction {
  public static final clojure.lang.Var const__0;

  public static {};
    Code:
       0: ldc           #11                 // String test
       2: ldc           #13                 // String a
       4: invokestatic  #19                 // Method clojure/lang/RT.var:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Var;
       7: checkcast     #21                 // class clojure/lang/Var
      10: putstatic     #23                 // Field const__0:Lclojure/lang/Var;
      13: return

  public test$a();
    Code:
       0: aload_0
       1: invokespecial #26                 // Method clojure/lang/AFunction."<init>":()V
       4: return

  public static java.lang.Object invokeStatic(java.lang.Object);
    Code:
       0: aload_0
       1: aconst_null
       2: astore_0
       3: invokestatic  #30                 // Method invokeStatic:(Ljava/lang/Object;)Ljava/lang/Object;
       6: areturn

  public java.lang.Object invoke(java.lang.Object);
    Code:
       0: aload_1
       1: aconst_null
       2: astore_1
       3: invokestatic  #30                 // Method invokeStatic:(Ljava/lang/Object;)Ljava/lang/Object;
       6: areturn
}


 Comments   
Comment by Nicola Mometto [ 06/Jan/17 10:12 AM ]

I just took a quick look at this, not an easy one to fix as handling recursive calls would likely require 2 passes over the whole defn AST, one to determine whether the defn is direct-linkable and the other one to build the AST using StaticInvokeExpr rather than InvokeExpr (using a stub Method using the analysis info rather than reflecting)

Comment by Alex Miller [ 06/Jan/17 2:03 PM ]

Yeah, Rich is aware of this and it's not done yet due to the issues you mentioned. It's hard!





[CLJ-2145] locals closed over by a ^:once fn aren't cleared if the fn is in a branch Created: 08/Apr/17  Updated: 11/Apr/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: compiler, locals-clearing

Attachments: Text File 0001-CLJ-2145-fix-clearing-of-locals-closed-over-by-a-FNO.patch    
Patch: Code
Approval: Triaged

 Description   

Minimal case:

(fn foo [x]
  (if true
    (^:once fn* []
     ;; x is not cleared here
     x)))

This is a severe bug as it means that every local used inside a loop or try/catch expression that the clojure compiler internally hoists in a FNONCE, in a conditional branch, cannot be cleared at the moment.

As a concrete example reported in slack,

;; THIS OOMs
(defn test1 [x]
  (if true
    (do
      (try (doseq [_ x] _))
      1)
    0))

(test1 (take 1000000 (range)))

;; THIS DOESN'T OOM 
(defn test2 [x]
  (do
    (try (doseq [_ x] _))
    1))

(test2 (take 1000000 (range)))

Approach: don't set a new clearing frame if the fn is ^:once and there's an existing clearing frame
Patch: 0001-CLJ-2145-fix-clearing-of-locals-closed-over-by-a-FNO.patch






[CLJ-992] `iterate` reducer Created: 10/May/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alan Malloy Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reducers

Attachments: Text File 0001-Add-reducers-iterate.patch     Text File iterate-reducer.patch    
Approval: Vetted

 Description   

Added a reducer implementation mirroring clojure.core/iterate.

Patch: iterate-reducer.patch

Screened by:



 Comments   
Comment by Alan Malloy [ 10/May/12 9:50 PM ]

Should I have made this implement Seqable as well? It wasn't clear to me, because as far as I could see this was the only function in clojure.core.reducers that's generating a brand-new sequence rather than transforming an existing one.

Comment by Alan Malloy [ 10/May/12 10:24 PM ]

Previous version neglected to include the seed value of the iteration in the reduce.

Comment by Jason Jackson [ 11/May/12 11:23 AM ]

Currying iterate seems useless, albeit not harmful.

While implementing repeat, I couldn't use currying. Because 1-arity is already reserved for infinite repeat ([n x] and [x], not [n x] and [n] if currying)

How about we just support currying for functions where last param is reducible?

Comment by Alan Malloy [ 18/Aug/12 7:16 PM ]

This new patch replaces the previous patch. As requested, I am splitting up the large issue CLJ-993 into smaller tickets.

Does not depend on any of my other reducer patches, but there will probably be some minor merge conflicts unless it is merged after CLJ-1045 and CLJ-1046, and before CLJ-993.

Comment by Ghadi Shayban [ 09/Jan/16 5:34 PM ]

iterate is now reducible





[CLJ-1386] Add transient? predicate Created: 17/Mar/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Devin Walters Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: collections, transient
Environment:

N/A


Attachments: Text File 0004-Add-transient-predicate.patch    
Approval: Triaged

 Description   

I've encountered situations where I wanted to check whether something was transient in order to know whether I should call assoc! or assoc, conj! or conj, etc.

This patch adds `transient?` as a predicate fn.



 Comments   
Comment by Alex Miller [ 17/Mar/14 10:21 AM ]

Patch needs a docstring and a test.

Comment by Devin Walters [ 17/Mar/14 4:42 PM ]

Alex: I figured that would be the case! Sorry about that. I've updated the patch. It now includes a docstring and has tests of `transient?` for #{}, [], and {}.

Thanks!

Comment by Alex Miller [ 17/Mar/14 9:48 PM ]

Thanks - please don't use the labels "patch" or "test" - those are covered by the Patch field.

Comment by Devin Walters [ 18/Mar/14 9:17 AM ]

Ah, sorry for the mixup Alex. I assumed you removed "patch" as a label the first time around to flag this ticket as still needing a vetted patch. My mistake.

Comment by Andy Fingerhut [ 21/Mar/14 1:42 PM ]

Patch 0001-Add-transient-predicate.patch dated Mar 17, 2014 applies cleanly to latest Clojure master, but fails a test because the new function transient? has no :added metadata. See most other Clojure functions in clojure.core for examples.

It also generates a new warning while running tests:

WARNING: transient? already refers to: #'clojure.core/transient? in namespace: clojure.test-clojure.data-structures, being replaced by: #'clojure.test-clojure.data-structures/transient?

There is an older (but equivalent) definition of transient? in test file data_structures.clj that should be removed when adding it to clojure.core

Comment by Devin Walters [ 22/Mar/14 11:29 PM ]

@Andy, the reason I did not add :added metadata is because I do not know if/when this patch will be accepted, and as a result, I don't really know if it will sneak into 1.6.X or 1.7. For now, I've put it in as 1.7. If it's in the running to be added sooner than that, let me know and I'll adjust it.

RE: The warning. Good catch. I've submitted a new patch which removes the private version of transient? from data_structures.clj. All tests pass.

Edit to Add: The latest patch as of this comment is now 0002-Add-transient-predicate.patch.

Comment by Andy Fingerhut [ 06/Aug/14 2:16 PM ]

Patch 0002-Add-transient-predicate.patch dated Mar 22 2014 no longer applies cleanly to latest Clojure master due to some changes committed earlier today. I haven't checked whether this patch is straightforward to update.

Comment by Devin Walters [ 06/Aug/14 4:11 PM ]

I've updated the patch to 0003-Add-transient-predicate.patch. This patch applies cleanly to the latest version of master.

Comment by Andy Fingerhut [ 29/Aug/14 4:44 PM ]

Patch 0003-Add-transient-predicate.patch dated Aug 6 2013 no longer applied cleanly to latest master after some commits were made to Clojure on Aug 29, 2014. It did apply cleanly before that day.

I have not checked how easy or difficult it might be to update this patch.

Comment by Devin Walters [ 31/Aug/14 12:01 AM ]

I've updated the patch to 0004-Add-transient-predicate.patch. This patch applies cleanly to the latest version of master.





[CLJ-1459] records should support transient Created: 05/Jul/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Yongqian Li Assignee: Unassigned
Resolution: Unresolved Votes: 5
Labels: defrecord


 Description   

user=> (defrecord R [a])
user.R
user=> (transient (->R nil))
ClassCastException user.R cannot be cast to clojure.lang.IEditableCollection clojure.core/transient (core.clj:3060)






[CLJ-1519] Added extra arity to clojure.core/ns-* fns Created: 04/Sep/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alex Baranosky Assignee: Unassigned
Resolution: Unresolved Votes: 4
Labels: enhancement, patch

Attachments: Text File new-ns-arity.patch    

 Description   

Hello,

Adds another arity where the "ns" parameter is set to a default value of *ns* in these fns:

ns-unmap, ns-resolve, ns-name, ns-map, ns-publics, ns-imports, ns-interns, ns-refers, ns-aliases, ns-unalias

I find I very often use ns-unalias and ns-unmap from the repl, and passing the *ns* arg gets a little tedious.






[CLJ-1534] Adding condp-> and condp->> macros to core library Created: 24/Sep/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Kuldeep Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: enhancement, macro

Attachments: File clj_1534.diff     File condp-threading-macros-25sept2014.diff    

 Description   

After introduction of cond-> and cond->> macros in 1.5. It makes sense to have condp-> and condp->> macros in the core library.

(condp-> {}
(complement :a) (assoc :a 1)
:a (assoc :b 2)) ;=> {:b 2, :a 1}

In the above example the result of each expr which was evaluated is being passed to the next predicate.



 Comments   
Comment by Andy Fingerhut [ 01/Oct/14 6:37 PM ]

Kuldeep, I cannot comment on whether this change is of interest to the Clojure developers, because I do not know.

I can say that the patch you have attached is not in the expected format. See the page below for instructions on creating a patch in the expected format:

http://dev.clojure.org/display/community/Developing+Patches

Comment by Kuldeep [ 28/Jan/15 11:31 AM ]

Rebased against master and generated patch as described in wiki.

Comment by Vitalie Spinu [ 12/Jul/16 5:21 AM ]

This is a very common pattern for me.

This is one way of dealing with such state-dependent conditionals:

(-> x
  (as-> y (if (:foo y) (assoc y :boo 0) y))
  ...)

The proposed `condp->` is much more readable:

(-> x
  (condp-> :foo (assoc :boo 0))
  ...)

BTW, `condp->` is not exactly the counterpart of `condp`. So maybe shorter `pred->` or `p->` are better names for this.





[CLJ-252] Support typed non-primitive fields in deftype Created: 29/Jan/10  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Assembla Importer Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: deftype


 Description   

Right now hints are accepted but not used as field type.



 Comments   
Comment by Assembla Importer [ 24/Aug/10 6:07 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/252





[CLJ-1280] Create reusable exception that can carry file/line/col info Created: 18/Oct/13  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: None


 Description   

This concept already exists in multiple places in Clojure - Compiler$CompilerException and the Exception classes buried in EdnReader and LispReader. It would also be useful in other places where IllegalArgument or other other exceptions are thrown.

For example, this protocol exception throws an IllegalArgumentException and could transmit the file, line, and column info at the location of the error but it seems weird to use any of the existing exceptions for this purpose.

(defprotocol Bar (m [this]) (m [this arg]))


 Comments   
Comment by Kevin Downey [ 18/Apr/14 12:09 AM ]

seems like ExceptionInfo can do this





[CLJ-995] sorted-set doesn't support IEditableCollection Created: 13/May/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Moritz Ulrich Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: collections


 Description   

I think sorted-set (PersistentTreeSet) should implement the transient interface. It's a special-purpose set and should be usable just like every normal set.



 Comments   
Comment by Michel Alexandre Salim [ 04/Jun/12 2:32 AM ]

Note that this would require PersistentTreeMap to implement IEditableCollection as well.

Comment by Andy Fingerhut [ 24/Feb/15 10:00 AM ]

Anyone wishing for sorted sets/maps with transients should consider the data.avl library, which has them: https://github.com/clojure/data.avl





[CLJ-1729] Make Counted and count() return long instead of integer Created: 12/May/15  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: None


 Description   

Currently count() returns an int - should bump that up to a long.

On long overflow, count() should throw ArithmeticException. Also see CLJ-1229.



 Comments   
Comment by Erik Assum [ 07/Jul/15 9:24 AM ]

Looking at this, there are some problems like in
clojure.lang.RT#toArray line 1658
where you create a new Object array based on the count of a collection.
It seems as if new Object[] takes an int as a param, so one would have to downcast the long to an int for this to work.

Comment by Alex Miller [ 07/Jul/15 9:39 AM ]

If you're creating an Object[] greater than 2147483647, you may have other problems.

But yes, this ticket definitely needs a more thorough analysis as to what is affected. In this case, I think if the count is <= Integer/MAX_VALUE, then it should proceed and otherwise should throw an exception.

Comment by Erik Assum [ 08/Jul/15 8:19 AM ]

hmmm, this also causes problems wrt java.util.Collection size:
clojure.lang.APersistentSet#size line 164
Where size is specified by

http://docs.oracle.com/javase/7/docs/api/java/util/Collection.html#size()





[CLJ-993] `range` reducer Created: 10/May/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alan Malloy Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: reducers

Attachments: Text File 0001-CLJ-993-implement-range-and-iterate-as-reducers.patch     Text File 0001-CLJ-993-implement-range-and-iterate-as-reducers.patch     Text File 0001-CLJ-993-implement-range-as-a-reducer.patch     Text File 0002-Make-iterate-and-range-Seqable.patch     Text File 0003-Implement-fold-for-Range-objects.patch     Text File just-iseq.patch     Text File range-reducer.patch    

 Description   

Rich mentioned in IRC today he'd welcome a reducer implementation of clojure.core/range. Now that I've figured out how to do iterate, I figure I'll knock out range as well by the end of the night. Just opening the issue early to announce my intentions to anyone else interested in doing it.



 Comments   
Comment by Alan Malloy [ 10/May/12 10:45 PM ]

Implemented range. A separate commit is attached, making iterate and range also Seqable, since I'm not sure if that's desired. Apply it or not, as you prefer.

Comment by Jason Jackson [ 11/May/12 11:20 AM ]

Range should be foldable

Comment by Alan Malloy [ 11/May/12 12:53 PM ]

Yep, so it should. Time for me to dig into the folding implementations!

Comment by Alan Malloy [ 11/May/12 2:42 PM ]

Should I fold (har har) all of these commits into one? I don't know what is preferred on JIRA, and I also don't know whether range/iterate should be seqable or if I should just drop the second commit.

Comment by Rich Hickey [ 11/May/12 3:21 PM ]

Yes, please merge these together, it's hard to see otherwise (I can barely read diffs as is . range and iterate shouldn't be novel in reducers, but just enhanced return values of core fns. The enhancement (e.g. protocol extensions) can come by requiring reducers since it can't be leveraged without it. Also, I'm not sure how I feel about an allocating protocol for 'splittable' - I've avoided it thus far.

Comment by Alan Malloy [ 11/May/12 3:30 PM ]

So you want clojure.core/range to return some object (a Range), which implements Counted and Seqable (but isn't just a lazy-seq), and then inside of clojure.core.reducers I extend CollReduce and CollFold to that type? Okay, I can do that.

I don't quite follow what you mean by an allocating protocol. I see your point that my fold-by-halves which takes a function in is analogous to a protocol with a single function, but it doesn't allocate anything more than foldvec already does - I just pulled that logic out so that the fork/join fiddly work doesn't need to be repeated in everything foldable. Do you have an alternative recommendation, or is it just something that makes you uneasy and you're still thinking about?

Comment by Rich Hickey [ 11/May/12 3:52 PM ]

While vector-fold allocs subvecs, the halving-fn must return a new vector, for all implementations. It's ok, I don't think it's likely to dominate (since fj needs new closures anyway). Please proceed, but keep range and iterate in core. They are sources, not transformers, and only transformers (which must be different from their seq-based counterparts) must reside in reducers. Thanks!

Comment by Stuart Sierra [ 11/May/12 5:01 PM ]

One big patch file is preferred, although that file may contain multiple commits if that makes the intent clearer.

When adding a patch, update the description of the ticket to indicate which file is the most recent. Leave old patch files around for historical reference.

Comment by Alan Malloy [ 11/May/12 9:00 PM ]

It's looking harder than I expected to move iterate and range into core.clj. My plan was to just have them implement Seqable, which is easy enough, but currently they are actually instances of ISeq, because they inherit from LazySeq. A bunch of code all over the place (eg, to print them in the repl) depends on them being ISeq, so I can't just ignore it. To implement all of these methods (around thirty) would take a large amount of code, which can't easily be shared between Iteration, Range, and any future reducible sources that are added to core.clj.

I could write a macro like (defseq Range [start end step] Counted (count [this] ...) ...) which takes normal deftype args and also adds in implementations for ISeq, Collection, and so forth in terms of (.seq this), which will be a LazySeq. However, this seems like a somewhat awkward approach that I would be a little embarrassed to clutter up core.clj with. If anyone has a better alternative I will be pleased to hear it. In the mean time, I will go ahead with this macro implementation, in case it turns out to be the best choice.

Comment by Alan Malloy [ 11/May/12 11:52 PM ]

– This patch subsumes all previous patches to this issue and to CLJ-992

In order to create an object which is both a lazy sequence and a
reducible source, I needed to add a macro named defseq to core_deftype.
It is basically a reimplementation of clojure.lang.LazySeq as a clojure
macro, so that I can "mix in" lazy-sequence functions into a new class
with whatever methods are needed for reducing and folding.

If we wanted, we could use this macro to implement lazy-seq in clojure instead of in java, but that's unrelated so I didn't do that in this patch.

As noted in a previous comment, defseq may not be the right approach, but this works until something better is suggested.

Comment by Alan Malloy [ 11/May/12 11:58 PM ]

I accidentally included an implementation of drop-while in this patch, which I was playing around with to make sure I understood how this all works. I guess I'll leave it in for the moment, since it works and is useful, but I can remove it, or move it to a new JIRA ticket, if it's not wanted at this time.

Comment by Rich Hickey [ 12/May/12 10:52 AM ]

Ok, I think this patch is officially off the rails. There must be a better way. Let's start with: touching core/deftype and reimplementing lazy-seq as a macro are off the table. The return value of range doesn't have to be a LazySeq, it has to be a lazy seq, .e.g. implement ISeq (7 methods, not 30) which it can do by farming out to its existing impl. It can also implement some new interface for use by the reducer logic. There is also still clojure.lang.Range still there, which is another approach. Please take an extremely conservative approach in these things.

Comment by Alan Malloy [ 12/May/12 5:53 PM ]

Okay, thanks for the feedback - I'm glad I went into that last patch knowing it was probably wrong . I thought I would need to implement the java collection interfaces that LazySeq does, eg java.util.List, in order to avoid breaking interop functions like (defn range-list [n] (ArrayList. (range n))). If it's sufficient to implement ISeq (and thus IPersistentCollection), then that's pretty manageable.

It's still an unpleasant chunk of boilerplate for each new source, though; would you welcome a macro like defseq if I didn't put it in core_deftype? If so, it seems like it might as well implement the interop interfaces; if not, I can skip them and implement the 7 (isn't it more like 9?) methods in ISeq, IPersistentCollection, and Seqable for each new source type.

Thanks for pointing out clojure.lang.Range to me - I didn't realize we had it there. Of course with implementation inheritance it would be easy to make Range, Iteration, etc inherit from LazySeq and just extend protocols from them. But that means moving functionality out of clojure and into java, which I didn't think we'd want to do.

I'll put together a patch that just implements ISeq by hand for both of these new types, and attach it probably later today.

Comment by Alan Malloy [ 12/May/12 7:49 PM ]

So I've written a patch that implements ISeq, but not the java Collections interfaces, and it mostly works but there are definitely assumptions in some parts of clojure.core and clojure.lang that assume seqs are Collections. The most obvious to me (ie, it shows up when running mvn test) is RT/toArray - it tests for Collection, but never for ISeq, implying that it's not willing to handle an ISeq that is not also a collection. Functions which rely on toArray (eg to-array and vec) now fail.

This patch subsumes all previous patches on this issue, but is not suitable for application because it leaves some failing tests behind - it is intended only for intermediate feedback.

Comment by Rich Hickey [ 13/May/12 8:50 AM ]

It would be a great help if, time permitting, you could please write up the issues, challenges and options you've discovered somewhere on the dev wiki (even a simple table would be fantastic). I realize this has been a challenging task, and at this point perhaps we should opt for the more modest reducers/range and reducers/iterate and leave the two worlds separate. I'd like at some point to unify range, as there are many extant ranges it would be nice to be able to fold, as we can extant vectors.

Comment by Jason Jackson [ 13/May/12 9:24 AM ]

Should r/range return something Seqable and Counted?

If so, I'll do the same for r/repeat.

Comment by Alan Malloy [ 13/May/12 1:59 PM ]

I've sketched out a description of the issues and options. I'm not very familiar with the dev wiki and couldn't figure out where was the right place to put this. "release.next" seems to still be about 1.4 issues, and I don't know if it's "appropriate" to create a whole new category for this. It's available as a gist until a better home can be found for it.

Comment by Alan Malloy [ 23/May/12 7:54 PM ]

Here's a single patch summing up the state Rich suggested "rolling back" to: separate r/range and r/iterate functions. I haven't heard any feedback since doing the writeup Rich asked for, so am not making any further progress at the moment; if something other than this patch is desired just let me know.

Comment by Rich Hickey [ 14/Aug/12 2:07 PM ]

I prefer not to see the use of extend like this for new types. Perhaps this code is too DRY? Also, it does a lot in one patch which makes it hard to parse and accept. This adds Range, switches impl of vector folds etc. Can it be broken up into separate tickets that do each step that builds on the previous, e.g. one ticket could be: capture vector fold impl for reuse by similar things.

Comment by Alan Malloy [ 18/Aug/12 6:19 PM ]

Okay, I should be able to split it up over the weekend. I'll also see about converting fold-by-halves into a function that is used by Range/Vector, rather than a function that gets extended onto them.

Comment by Alan Malloy [ 18/Aug/12 7:18 PM ]

As requested, I have split up the large patch on this issue into four smaller tickets. The other three are: CLJ-1045, CLJ-1046, and CLJ-992.

CLJ-1045 contains the implementation of fold-by-halves, and as such this patch cannot be applied until CLJ-1045 is accepted. This ticket does not depend on the other two, but there will be minor merge conflicts if this is merged before them.

Comment by Ghadi Shayban [ 09/Jan/16 5:31 PM ]

range is now reducible.

Comment by Ghadi Shayban [ 29/Jun/16 9:17 PM ]

We should close this too. The only thing not covered in 1.7 is the foldable aspect.





[CLJ-994] repeat reducer Created: 11/May/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Jason Jackson Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: reducers

Attachments: Text File 0001-repeat-for-clojure.core.reducers.patch    

 Description   

i'm working on clojure.core/repeat reducer.



 Comments   
Comment by Andy Fingerhut [ 17/May/12 6:18 PM ]

Jason, have you tried to build this using JDK 1.6.0? I've tried on Mac OS X 10.6.8 + Oracle/Apple JDK 1.6.0 and Ubuntu 11.10 + IBM JDK 1.6.0, and on both it compiles, but during the tests fails with a ClassNotFoundException for class jsr166y.ForkJoinTask.

It builds and tests cleanly on Ubuntu 11.10 + Oracle JDK 1.7.0 for me.

Comment by Jason Jackson [ 17/May/12 6:41 PM ]

That's an issue that applies to all of core.reducers. Alan Malloy experienced it as well. I tried fixing it, but eventually just upgraded to JDK 1.7. I don't understand why it's happening.

Comment by Jason Jackson [ 19/May/12 2:55 PM ]

This issue is isolated to mvn test afaik.

When I include clojure inside a leiningen project, and add jsr166y.jar to lib directory, core.reducers works fine with java 1.6.

Comment by Andy Fingerhut [ 20/May/12 3:00 AM ]

Jason, you say it applies to all of core.reducers in your May 17, 2012 comment. I don't understand. Without your patch applied, I can run "./antsetup.sh ; ant" in a freshly-pulled Clojure git repo on either of the JDK 1.6.0 versions mentioned in my earlier comment, and do not get any errors during the tests. Are you saying perhaps that core.reducers currently has no tests that exercise the problem now, but your patch adds such tests that fail, even with no other changes to the code?

Comment by Jason Jackson [ 20/May/12 11:55 AM ]

Yah that's right. Now that you mention it, my patch is the first unit test to call r/fold (the existing tests do non-parallel reductions).

Comment by Andy Fingerhut [ 08/Jun/12 7:11 PM ]

With Stuart Halloway's commit to Clojure master on June 8, 2012 titled "let reducers tests work under ant", patch 0001-repeat-for-clojure.core.reducers.patch dated May 11, 2012 now runs correctly even the new unit tests requiring class jsr166y.ForkJoinTask with Oracle/Apple JDK 1.6 and Linux IBM JDK 1.6.

Comment by Jason Jackson [ 14/Aug/12 1:17 AM ]

I'm on the contributors list. Is this patch still needed?
sorry for long long delay.

Comment by Jason Jackson [ 14/Sep/12 2:37 PM ]

This patch should wait until http://dev.clojure.org/jira/browse/CLJ-993 is committed. I think there's a some shared code.

Comment by Ghadi Shayban [ 09/Jan/16 5:24 PM ]

repeat is now reducible in 1.7.0

Comment by Ghadi Shayban [ 29/Jun/16 9:05 PM ]

Can we close this ticket?

Comment by Alex Gunnarson [ 12/Mar/17 9:49 PM ]

I think it would be nice to have this reducer included for purposes of parallelism, or else extend `CollFold` to `clojure.lang.Repeat` (which is perhaps cleaner).





[CLJ-705] Make sorted maps and sets implement j.u.SortedMap and SortedSet interfaces Created: 05/Jan/11  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Rich Hickey Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Comments   
Comment by Andy Fingerhut [ 02/Jun/12 2:29 PM ]

This might be a duplicate of CLJ-248. See that one before working on this one, at least.





[CLJ-1108] Allow to specify an Executor instance to be used with future-call Created: 18/Nov/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Max Penet Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None

Attachments: Text File bac37b91230d8e4ab3a1e6042a6e8c4b7e9cbf53.patch     Text File clj-1108-enhance-future-call-patch-v2.txt    

 Description   

This adds an arity to future-call that expects a java.util.concurrent/ExecutorService instance to be used instead of clojure.lang.Agent/soloExecutor.



 Comments   
Comment by Andy Fingerhut [ 26/Dec/12 4:50 PM ]

Rich Hickey committed a change on Dec 21, 2012 to the future-call function that made the patch bac37b91230d8e4ab3a1e6042a6e8c4b7e9cbf53.patch dated Nov 18 2012 no longer apply cleanly.

clj-1108-enhance-future-call-patch-v2.txt dated Dec 26 2012 is identical to that earlier patch, except it has been updated to apply cleanly to the latest master.

It would be best if Max Penet, author of the earlier patch, could verify I've merged his patch to the latest Clojure master correctly.

Comment by Max Penet [ 27/Dec/12 2:25 AM ]

It's verified, it applies correctly to the latest master 00978c76edfe4796bd6ebff3a82182e235211ed0 .

Thanks Andy.





[CLJ-986] Adds an exit function to exit clojure process Created: 06/May/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: dennis zhuang Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

There is no standard function to exit the clojure process.
In java implementation,we use (System/exit 0),but in other implementations(CLR), i have to use another function.

Why not add a standard function in clojure.core?
For example:

(defn exit
([] (exit 0)
([status] (System/exit status)))

I think it's useful for us.






[CLJ-903] extend-protocol does not allow classnames as a String Created: 30/Dec/11  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.2, Release 1.3, Release 1.4
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Meikel Brandmeyer Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: interop


 Description   

In various places Clojure accepts classnames as String, eg. in gen-class or type hints. However it does not in extend-protocol. This does not allow simple specification of array types.

See also here: http://groups.google.com/group/clojure/browse_thread/thread/722a0c09d02bb0ac






[CLJ-153] Suggest adding set-precision! API to accompany with-precision Created: 12/Jul/09  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Assembla Importer Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: math


 Description   

Ticket #137 makes math-context</code> settable at the REPL. However, <code>math-context is not a public name in Clojure.

The related public function is with-precision</code> which works by pushing a new binding for <code>math-context</code>. This ticket suggests adding <code>set-precision!</code> to Clojure's public API. Its effect would be the same as <code>with-precision</code>, but accomplished by using <code>set!</code> on the current <code>math-context binding rather than by pushing a new binding.

Chouser suggests that we also add a doc string for math-context</code> noting that it is private and pointing the user to <code>with-precision</code> and <code>set-precision!. I agree.



 Comments   
Comment by Assembla Importer [ 24/Aug/10 12:55 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/153





[CLJ-1046] Drop-while as a reducer Created: 18/Aug/12  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alan Malloy Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reducers

Attachments: Text File drop-while-reducer.patch    

 Description   

Implement drop-while as a reducer. Follows the same atom-based strategy as drop and take.

Does not depend on any of my other reducer patches, but there will probably be some minor merge conflicts unless it is merged after CLJ-1045, and before CLJ-992 and CLJ-993.



 Comments   
Comment by Andy Fingerhut [ 03/Sep/14 8:11 PM ]

Patch drop-while-reducer.patch dated Aug 18 2012 no longer applies cleanly to latest master after some commits were made to Clojure on Sep 3, 2014.

I have not checked whether this patch is straightforward to update, nor do I know if there is interest in an updated patch, or whether transducers are the preferred way to go over reducers, and thus all reducers-related tickets will be closed. See the section "Updating stale patches" at http://dev.clojure.org/display/community/Developing+Patches for suggestions on how to update patches.





[CLJ-1679] Add fast path in seq comparison for structurally sharing seqs Created: 21/Mar/15  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: collections, performance, seq

Attachments: Text File 0001-CLJ-1679-do-pointer-checks-in-seq-equality.patch     Text File CLJ-1679-v2.patch     Text File CLJ-1679-v3.patch    
Patch: Code and Test

 Description   

Currently comparing two non identical seqs requires iterating through both seqs comparing value by value, ignoring the possibility of seq `a` and `b` having the same (pointer-equal) rest.

The proposed patch adds a pointer equality check on the seq tails that can make the equality short-circuit if the test returns true, which is helpful when comparing large (or possibly infinite) seqs that share a common subseq.

After this patch, comparisons like

(let [x (range)] (= x (cons 0 (rest x))))
which currently don't terminate, return true in constant time.

Patch: CLJ-1679-v3.patch



 Comments   
Comment by Michael Blume [ 23/Mar/15 12:52 PM ]

When this test fails (it fails on my master, but I've got a bunch of other development patches, I'm still figuring out where the conflict is), it fails by hanging forever. Maybe it'd be better to check equality in a future and time out the future?

Comment by Michael Blume [ 23/Mar/15 1:01 PM ]

like so =)

Comment by Nicola Mometto [ 23/Mar/15 1:11 PM ]

Makes sense, thanks for the updated patch

Comment by Michael Blume [ 23/Mar/15 1:24 PM ]

Hm, previous patch had a problem where the reporting logic still tries to force the sequence and OOMs, this patch prevents that.

Comment by Michael Blume [ 23/Mar/15 1:41 PM ]

ok, looks like CLJ-1515, CLJ-1603, and this patch, all combine to fail together, though any two of them work fine.

Comment by Michael Blume [ 23/Mar/15 1:43 PM ]

(And really there's nothing wrong with the source of this patch, it still works nicely to short-circuit = where there's structural sharing, it's just that the other two patches break structural sharing for ranges, so the test fails)

Comment by Nicola Mometto [ 23/Mar/15 2:02 PM ]

I see, I guess we'll have to change the test if the patches for those tickets get applied.





[CLJ-1720] Add clojure.core/pattern? predicate Created: 03/May/15  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Brandon Bloom Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: patch

Attachments: Text File CLJ-1720_v01.patch     Text File CLJ-1720_v02.patch    

 Description   

Just like http://dev.clojure.org/jira/browse/CLJ-1719 , this helps with clj/cljs compatibility.



 Comments   
Comment by Brandon Bloom [ 03/May/15 2:37 PM ]

See also http://dev.clojure.org/jira/browse/CLJS-1242

Comment by Brandon Bloom [ 03/May/15 2:48 PM ]

Whoops, uploaded wrong patch. Tests actually pass in this v02 patch.





[CLJ-1552] Consider kv support for transducers (similar to reducers fold) Created: 07/Oct/14  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: transducers


 Description   

In reducers, fold over a map has special support for kv. Consider whether/how to add this for transducers.



 Comments   
Comment by Marshall T. Vandegrift [ 16/Dec/14 11:13 AM ]

We don't have a JIRA "unvote" feature, but I'd like to register my vote against this proposed enhancement. As a heavy user of clojure.core.reducers, I consider the switch to k-v semantics when reducing a map to be a significant mis-feature. As only an initial transformation function applied directly to a map is able to receive the k-v semantics (a limitation I can’t see how would not carry over to transducers), this behavior crops up most frequently when re-ordering operations and discovering that an intermediate map has now caused an airity error somewhere in the middle of a chain of threaded transformations. I’ve never found cause to invoke it intentionally.

Comment by Ghadi Shayban [ 21/Jan/16 9:17 PM ]

Marshall, there really isn't a proposed enhancement, yet. So there's nothing to be against! Your input is valuable. (Regarding c.c.reducers, that is a separate problem – yes that behavior is surprising)

Considering kv-support for transducers:
Is it useful to have some functions that transform reduce-kv style reducing functions (fn [result k v])?

Ignore naming:
map-key
map-val
map-keyval
filter-*

These could be mechanically generated. You wouldn't have to have a kv-version for every transducer currently in core. Some like map or filter could specifically apply to the key and ignore the val, or v.v.

Some things like map's transducer would be arity-incompatible (map's transducer has a varargs arity).





[CLJ-2083] spec for printable/readable/edn data Created: 12/Dec/16  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.9
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Brandon Bloom Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

When spec'ing some things, I've used `any?` in a few cases where it is overly permissive. In particular, sometimes I need to specify a value must be printable/readable, such as when a value may wind up in an edn file. Similarly, I've needed to spec something must have non-generative value-identity, ie. ban closures, etc. Printable/readable or simply `edn?` would be a much better approximation than `any?`.



 Comments   
Comment by Brandon Bloom [ 12/Dec/16 1:08 PM ]

I realize that an edn? predicate would have O(N) runtime, vs an edn spec that could take advantage of every/every-kv etc for sampling conformance.

Comment by Herwig Hochleitner [ 12/Dec/16 11:12 PM ]

Related: CLJ-1527





[CLJ-2173] LispReader.java and EdnReader.java exception messages could be much more informative. Created: 31/May/17  Updated: 31/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.9
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Russ Olsen Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: errormsgs, reader
Environment:

Any


Approval: Triaged

 Description   

The messages in the exceptions thrown by the readers would be much more informative if they included readily available information. There are many instances of this, but to name a few specific instances (all from LispReader.java, though there in most cases there are corresponding problems in EdnReader.java):

  • If the RegexReader class hits an unexpected EOF, it reports "EOF while reading regex". It would be helpful if the message included the first few characters of the regex it was trying to read – available in sb – as a guide to the person trying to locate the problem.
  • The same logic applies to StringReader.
  • In NamespaceMapReader, the error thrown if the namespaced map is not in fact a map could include the namespace symbol.
  • Whenever an odd number of elements in a map is detected, the exception could at least report the number of elements that the bad map did include, something like: "Map literal cannot contain 7 forms. Map literals must contain an even number of forms." Even better would be the first few forms.
  • The "Metadata can only be applied to IMetas" exception in MetaReader is not nearly as helpful as it could be. At the very least it should report the class of the thing that is not an IMeta.
  • With an additional argument, readDelimitedList could report the kind of thing that it was reading in the event that it hit the EOF. Without the additional argument it still report that it hit an EOF while trying to read the first or 4th or 29 element of a collection.





[CLJ-1551] Consider transducer support for primitives Created: 07/Oct/14  Updated: 28/Jun/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: Backlog

Type: Feature Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: transducers

Approval: Vetted

 Description   

Need to consider how we can support primitives for transducers. In particular it may be that IFn needs overloading for L/D in addition to O.






[CLJ-1863] Bad type hints on a defn cause the compiler to throw a NPE Created: 04/Dec/15  Updated: 10/Jul/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.8
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Timothy Baldridge Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: compiler, errormsgs, typehints

Approval: Triaged

 Description   

After CLJ-1232 was committed to master, it is possible for the Clojure compiler to throw a NPE if a defn is type hinted with a invalid type. This surfaces in CLJS where the defn macro is re-used by the ClojureScript compiler, but I think it raises the question: "Should a bad type hint result in a compiler exception?"

The offending line can be found here on GitHub: https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L247



 Comments   
Comment by Alex Miller [ 18/Dec/15 8:12 AM ]

This is basically the same as CLJ-1868, but I think what you are asking here is whether bad type hints should be ignored or throw any exception, right?

(Whereas CLJ-1868 is about which exception/message is thrown)

Comment by Timothy Baldridge [ 18/Dec/15 8:22 AM ]

Agreed. I think another possible solution would be to update CLJS to not use the CLJ defn, but I still think that a bad type hint should just be ignored.

Comment by Nicola Mometto [ 18/Dec/15 8:29 AM ]

I don't agree that we shoud ignore bad type hints.
If the compiler knows that something is wrong, it should tell the user immediately rather than silently ignoring and potentially failing at runtime later

Comment by Alex Miller [ 10/Jul/17 2:09 PM ]

Description could use some examples





[CLJ-1077] thread-bound? returns true (implying set! should succeed) even for non-binding thread Created: 26/Sep/12  Updated: 01/Feb/16

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Paul Stadig Assignee: Unassigned
Resolution: Unresolved Votes: 5
Labels: None

Attachments: File thread-bound.diff    
Patch: Code
Approval: Prescreened

 Description   

thread-bound? returns true for thread-local bindings that were not bound by the current thread. This is at odds with the docstring, which states that if true is returned, set! should succeed.

ere is an example REPL session where a thread establishes a binding, those bindings are conveyed to a second thread, the second thread checks thread-bound? to see if it can set the binding, thread-bound? returns true indicating that the binding can be set, the second thread tries to set the binding, and the second thread gets an IllegalStateException:

    Clojure 1.5.1
    user=> (def ^:dynamic *set-me* nil)
    #'user/*set-me*
    user=> (defn try-to-set [] (binding [*set-me* 1] (doall (pcalls #(if (thread-bound? #'*set-me*) (set! *set-me* (inc *set-me*)))))))
    #'user/try-to-set
    user=> (try-to-set)
    IllegalStateException Can't set!: *set-me* from non-binding thread  clojure.lang.Var.set (Var.java:230)
    user=> 

Approach: thread-bound? should return false in the case where there is a binding and that binding was not established by the current thread. The patch adds a new function to Var as core does not have visibility into the non-public Var$TBox.

Patch: thread-bound.diff

Screened by: Alex Miller



 Comments   
Comment by Paul Stadig [ 01/Oct/12 10:07 AM ]

I have attached a patch that changes clojure.lang.Var and clojure.core/thread-bound? to only return true if a Var is set!-able.

Comment by Alex Miller [ 19/Aug/13 12:16 PM ]

REPL example?

Comment by Joe Gallo [ 20/Aug/13 7:55 AM ]

Sure thing, Alex – here's a repl example I just ran this morning.

; nREPL 0.1.7
user> (def ^:dynamic *set-me* nil)
#'user/*set-me*
user> (defn try-to-set [] (binding [*set-me* 1] (doall (pcalls #(if (thread-bound? #'*set-me*) (set! *set-me* (inc *set-me*)))))))
#'user/try-to-set
user> (try-to-set)
IllegalStateException Can't set!: *set-me* from non-binding thread  clojure.lang.Var.set (Var.java:230)
user>




[CLJ-790] Primitive type hints on function names should print error message Created: 10/May/11  Updated: 10/Jul/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Alan Dipert Assignee: Alan Dipert
Resolution: Unresolved Votes: 2
Labels: errormsgs, typehints

Approval: Triaged

 Description   

Functions returning primitives are hinted with metadata on the argument list, not on the function name. Using a primitive type hint on a function name should print an error message.

Currently, misplaced primitive hints are read without error.



 Comments   
Comment by Andy Fingerhut [ 23/Feb/15 9:20 PM ]

One can type hint a primitive value on a Var naming a function, or any value one wants, like so:

(def {:tag 'long} foo 17)

(defn {:tag 'double} bar [x y]
(* 2.0 x y))

I think it is odd that one must use {:tag 'long} instead of ^long, since trying to use ^long ends up giving the useless type hint that is the value of the function clojure.core/long.

However, the Clojure compiler will use the primitive type hints as shown in the examples above to avoid reflection in appropriate Java interop calls, so making them an error seems undesirable.

Comment by lvh [ 02/Jul/16 10:07 AM ]

Alternatively, perhaps the compiler could simply use the type hint? While ^long is useless now, its intent seems unambiguous.

Comment by Alex Miller [ 10/Jul/17 2:10 PM ]

Description could use some examples





[CLJ-1777] Add function version of vswap! Created: 13/Jul/15  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7, Release 1.8
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 4
Labels: None

Attachments: Text File 0001-CLJ-1777-Change-vswap-from-a-macro-to-an-inlineable-.patch     Text File 0001-CLJ-1777-Change-vswap-from-a-macro-to-an-inlineable-v2.patch    

 Description   

Volatiles and vswap! were added in 1.7 as performant mechanisms to achieve uncoordinated mutation to the language.
given the fact that their addition was a performance-centric one, vswap! was implemented as a macro rather than a normal function to avoid runtime dereference of the function var and the optional apply overhead in case of multiple args.

However this:
-is not necessary
-breaks the api parallelism between volatile/atom swap!/vswap! reset!/vreset!
-makes impossible certain use cases (vswaps! in update-in forms)
-is potentially confusing given that swap! is a function

Infact the macro can be replaced with a function with :inline metadata.
This is a strictly additive change that will make so that for all the current valid usages of vswap! nothing will change, it will still be macroexpanded by the inliner and additionally since it is now a function it can be used in HOF contexts where it's not unusual to see swap! used.



 Comments   
Comment by Alex Miller [ 13/Jul/15 8:07 PM ]

Nicola, please don't set the fix version on tickets.

Comment by Nicola Mometto [ 13/Jul/15 8:10 PM ]

Sorry, I mixed the fix version with the affected field

Comment by Greg Chapman [ 09/Mar/16 11:41 AM ]

An additional drawback to the current macro is that it will result in double evaluation of the vol expression:

user=> (macroexpand '(vswap! (return-a-vol) inc))
(. (return-a-vol) reset (inc (.deref (return-a-vol))))
Comment by Alex Miller [ 10/Mar/16 9:22 AM ]

I don't think Rich is interested in expanding the use of inline.

Re Greg's comment, that would be considered if you want to make a second ticket.

Comment by Nicola Mometto [ 10/Mar/16 12:31 PM ]

Not really sure I understand the adversion to using inline – it works perfectly fine and this is the exact use-case for it: a function that we want to inline for performance reason.

I really fail to see the reasoning behind making what should be a function, a macro, just for the sake of not using inline.

Comment by Phill Wolf [ 19/Mar/16 8:59 AM ]

Adding :inline to existing functions may be deplored as an unprincpled, sloppy, desperate, tragic compromise, and a slippery slope. But vswap! is the opposite case: The macro is what already exists, somewhat idiosyncratically. Pairing it with a function would make it more wholesome, not less.





[CLJ-274] cannot close over mutable fields (in deftype) Created: 23/Feb/10  Updated: 12/Sep/15

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: Backlog

Type: Defect Priority: Major
Reporter: Anonymous Assignee: Unassigned
Resolution: Unresolved Votes: 2
Labels: deftype

Approval: Vetted

 Description   

Simplest case:

user=>
(deftype Bench [#^{:unsynchronized-mutable true} val]
  Runnable
  (run [_]
    (fn [] (set! val 5))))

java.lang.IllegalArgumentException: Cannot assign to non-mutable: val (NO_SOURCE_FILE:5)

Functions should be able to mutate mutable fields in their surrounding deftype (just like inner classes do in Java).

Filed as bug, because the loop special form expands into a fn form sometimes:

user=>
(deftype Bench [#^{:unsynchronized-mutable true} val]
  Runnable
  (run [_]
    (let [x (loop [] (set! val 5))])))
java.lang.IllegalArgumentException: Cannot assign to non-mutable: val (NO_SOURCE_FILE:9)


 Comments   
Comment by Assembla Importer [ 01/Oct/10 9:35 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/274

Comment by Assembla Importer [ 01/Oct/10 9:35 AM ]

donmullen said: Updated each run to [_] for new syntax.

Now gives exception listed.

Comment by Assembla Importer [ 01/Oct/10 9:35 AM ]

richhickey said: We're not going to allow closing over mutable fields. Instead we'll have to generate something other than fn for loops et al used as expressions. Not going to come before cinc

Comment by Nicola Mometto [ 30/Jan/15 7:37 AM ]

The patch for CLJ-1226 makes this work:

(deftype Bench [#^{:unsynchronized-mutable true} val]
Runnable
(run [_]
(let [x (loop [] (set! (.val _) 5))])))

If there's interest, I could provide a patch that converts closed over mutable field access by generated fns (for loop/try) into field access on closed over "this", i.e. val -> (.val this)

Comment by Nicola Mometto [ 30/Jan/15 7:39 AM ]

Related tickets: CLJ-1075 CLJ-1023

Comment by Nicola Mometto [ 12/Sep/15 5:35 AM ]

CLJ-701 could probably make the loop case working





[CLJ-1256] Support type-hinted overrides of function parameters Created: 06/Sep/13  Updated: 15/May/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Feature Priority: Major
Reporter: Mike Anderson Assignee: Unassigned
Resolution: Unresolved Votes: 3
Labels: compiler, interop, typehints


 Description   

Problem: in many cases, the Clojure compiler has enough information about the type of a function argument to statically emit maximally efficient code on the JVM (i.e. without instance? checks, type casts or other forms of dynamic polymorphic dispatch). We are currently unable to do so in Clojure, which pushes developers with strong performance requirements to use some unidiomatic or convoluted workarounds.

Proposal is simply to allow functions to take type-hinted overloads of function arguments, e.g.

(defn foo
([^double x] (Math/floor x))
([^float x] (Math/floor (double x)))
([^String s] (count s)))

An "Object" version of the code with the correct arity will always be emitted, which will maintain compatibility with the IFn interface and ensure that the function can still be used in dynamic / interactive contexts. If the "Object" version is not explicitly provided, then it will be generated to use instance? checks that subsequently delegate to the appropriate typed version of the function (or throw an InvalidArgumentException if no match is found).

Matching rules would be the same as Java.

This will be backwards compatible with all existing uses of defn. In particular, it should extend / enhance / supercede the existing handling of primitive functions.

In the future, this technique might be used alongside core.typed to ensure that the most efficient function version is chosen based on type inference.






[CLJ-1662] folding over hash-map nested hash-map throws exception Created: 17/Feb/15  Updated: 15/Aug/17

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6, Release 1.7, Release 1.8, Release 1.9
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Francis Avila Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: reducers
Environment:

JVM 1.7.0_76, 1.8


Attachments: Text File CLJS-1662.patch    
Patch: Code and Test
Approval: Triaged

 Description   

I got a baffling exception in a recursive function that folds. REPL transcript below:

nREPL server started on port 57818 on host 127.0.0.1 - nrepl://127.0.0.1:57818
REPL-y 0.3.5, nREPL 0.2.6
Clojure 1.7.0-alpha5
Java HotSpot(TM) 64-Bit Server VM 1.7.0_76-b13
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=> (use 'foldtest.core)
nil
user=> (source leafs)
(defn leafs [xs]
  (->> (r/mapcat (fn [k v]
                   (if (map? v)
                     (leafs v)
                     [[k v]])) xs)
       (r/foldcat)))
nil
user=> (leafs (hash-map :a (hash-map :b 1 :c 2)))

ClassCastException clojure.lang.PersistentHashMap$1 cannot be cast to clojure.lang.IFn  clojure.core.reducers/fjinvoke (reducers.clj:48)
user=> (pst)
ClassCastException clojure.lang.PersistentHashMap$1 cannot be cast to clojure.lang.IFn
	clojure.core.reducers/fjin