Bug 175124 – [Linux][WTF] Use one global semaphore to notify thread suspend and resume completion

• Component: New Bugs
• Status: RESOLVED FIXED

[Yusuke Suzuki]

[Linux][WTF] Use one global semaphore to notify thread suspend and resume completion

[Yusuke Suzuki]

Created attachment 317109 [details]
Patch

[Yusuke Suzuki]

Comment on attachment 317109 [details]
Patch

ok, ready.

[Carlos Garcia Campos]

Comment on attachment 317109 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=317109&action=review

> Source/WTF/wtf/ThreadingPthreads.cpp:89
> +    Semaphore(unsigned initialValue)

explicit?

> Source/WTF/wtf/ThreadingPthreads.cpp:92
> +        int sharedBetweenProcesses = 0;
> +        sem_init(&m_platformSemaphore, sharedBetweenProcesses, initialValue);

Do we really need a local variable? or is it to document what that 0 means?

> Source/WTF/wtf/ThreadingPthreads.cpp:202
> +    globalSemaphoreForSuspendResume.construct(0);

This is the only place it's constructed and we always pass 0 as initial value, right?

[Yusuke Suzuki]

Comment on attachment 317109 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=317109&action=review

>> Source/WTF/wtf/ThreadingPthreads.cpp:89
>> +    Semaphore(unsigned initialValue)
> 
> explicit?

Yeah, nice. Fixed.

>> Source/WTF/wtf/ThreadingPthreads.cpp:92
>> +        sem_init(&m_platformSemaphore, sharedBetweenProcesses, initialValue);
> 
> Do we really need a local variable? or is it to document what that 0 means?

Yes, it is to document what that 0 means.

>> Source/WTF/wtf/ThreadingPthreads.cpp:202
>> +    globalSemaphoreForSuspendResume.construct(0);
> 
> This is the only place it's constructed and we always pass 0 as initial value, right?

Right. initializePlatformThreading() is called from initializeThreading(). And its content is guarded by call_once.
Thus, this construction only happens once. And it should be done before using Threading. (initializeThreading() calls this function and constructs this semaphore.).

[Yusuke Suzuki]

Committed r220201: <http://trac.webkit.org/changeset/220201>

[Radar WebKit Bug Importer]

<rdar://problem/33697497>