Details
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Type:
Enhancement
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Status:
Open
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Priority:
Minor
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Resolution: Unresolved
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Affects Version/s: Release 1.4
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Fix Version/s: None
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Component/s: None
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Labels:
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Patch:Code
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Approval:Vetted
Description
This allows print-sequential to be interrupted by Thread.interrupt(), rather than requiring clients to resort to Thread.stop(). This is especially helpful when printing very large sequences.
See also clojure-dev discussion at https://groups.google.com/d/topic/clojure-dev/vs0RNUQXiYE/discussion
Attachments
Activity
Andy: The only caveat I can think of with checking Thread/interrupted less often is in the case of deeply nested collections.
Stu: Dev-time use was the original reason for opening this, yes. But I can imagine it being needed for anytime a thread can be interrupted, whether that's by ctrl-c or other means.
My original thinking, performance-wise, was that once we're already doing IO, we're probably not too concerned with CPU-bound checks like this, so I didn't bother with it. I guess with an SSD that's not as likely to be true.
Locally (w/ my SSD), I'm seeing that Andy's benchmark of printing a million numbers is about a second slower than the baseline with my original patch (12.08s -> 13.10s), and about the same with Andy's patch (12.08s -> 11.75s). Decreasing to a thousand numbers doesn't really show any difference (every version completes in ~1.3s). Bumping to 2 million adds 2 seconds above the baseline with my patch, and Andy's is again just a bit faster than the baseline (somehow). Bumping to 5 million runs me out of heap space 
In a quickly hacked up performance test on Mac OS X 10.6.8 + Oracle/Apple JDK 1.6.0_35 which I can attach, I saw about a 9% to 10% slowdown for Colin's patch in printing large vectors.
I have a modified patch that only calls Thread/interrupted after every 20 items are printed, and with that version the slowdown versus the original code was about 3% to 4%.
Colin, would there be any down side to checking Thread/interrupted less often for your purposes?
To run performance test, edit attachment compile.sh to point at your clojure.jar, put file perftest-print.clj in the same directory, and run ./compile.sh It should work on Mac or Linux.