Bug 174298 – It should be easy to decide how WebKit yields

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Filip Pizlo]

Currently, we call std::this_thread::yield(), which is super silly.  In all other regards, we go to the bare metal for threads.  We should use a syscall via a WTF abstraction, rather than using a C++ standard library abstraction.

[Filip Pizlo]

Created attachment 314950 [details]
the.patch

I'm still improving this, but it can already be used for yielding experiments.

[Filip Pizlo]

Comment on attachment 314950 [details]
the.patch

Actually, I like this approach.  R? it is.

[Build Bot]

Attachment 314950 [details] did not pass style-queue:


ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
Total errors found: 2 in 14 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Yusuke Suzuki]

Comment on attachment 314950 [details]
the.patch

View in context: https://bugs.webkit.org/attachment.cgi?id=314950&action=review

r=me with comment about windows fix.

> Source/WTF/wtf/Threading.cpp:190
> +void Thread::yield()
> +{
> +    sched_yield();
> +}

`sched_yield` is not defined in Windows.
So, let's define this in ThreadingPthreads.cpp. And in ThreadingWin.cpp, let's define it with SwitchToThread().

[Filip Pizlo]

Created attachment 315489 [details]
the patch

[Filip Pizlo]

Created attachment 315492 [details]
the patch

[Saam Barati]

Comment on attachment 315492 [details]
the patch

r- for now because this patch contains a bunch of other stuff that appears to be from the WebKit2->WebKit rename and is therefore hard to review.

[Filip Pizlo]

Created attachment 315769 [details]
the patch

This time, without the ridiculousness.

[Build Bot]

Attachment 315769 [details] did not pass style-queue:


ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
ERROR: Source/WTF/wtf/LockAlgorithm.h:125:  The parameter name "lock" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/LockAlgorithm.h:131:  The parameter name "lock" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/LockAlgorithm.h:131:  The parameter name "fairness" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/RunLoopTimer.h:33:  Alphabetical sorting problem.  [build/include_order] [4]
Total errors found: 6 in 32 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Comment on attachment 315769 [details]
the patch

r=me. Looks like you may need to do something for windows

[Filip Pizlo]

Created attachment 316113 [details]
patch for landing

[Build Bot]

Attachment 316113 [details] did not pass style-queue:


ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
ERROR: Source/WTF/benchmarks/ToyLocks.h:121:  Wrong number of spaces before statement. (expected: 20)  [whitespace/indent] [4]
ERROR: Source/WTF/wtf/LockAlgorithm.h:125:  The parameter name "lock" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/LockAlgorithm.h:131:  The parameter name "lock" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/LockAlgorithm.h:131:  The parameter name "fairness" adds no information, so it should be removed.  [readability/parameter_name] [5]
ERROR: Source/WTF/wtf/RunLoopTimer.h:33:  Alphabetical sorting problem.  [build/include_order] [4]
Total errors found: 6 in 32 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Filip Pizlo]

Landed in https://trac.webkit.org/changeset/219763/webkit