1728056 - Remove lock when profiling current thread in profiler_suspend_and_sample_thread

Status: RESOLVED FIXED

(Core :: Gecko Profiler, task, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Remaining TODO from bug 1722261:

                // TODO: Remove this lock when on-thread sampling doesn't
                // require it anymore.
                PSAutoLock lock;

It was left for simplicity, as the lock is used in some parts of this code.
But it's only used in the "non-synchronous" code path, i.e., when sampling another thread.
So when sampling the current thread, we could avoid locking the profiler mutex.

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Attachment: Bug 1728056 - Remove lock when profiling current thread in profiler_suspend_and_sample_thread - r?canaltinova

The lock in the inner profiler_suspend_and_sample_thread function was only needed on the !aIsAsynchronous code path.
So instead, the pointer to the lock is passed in this case, otherwise nullptr indicates that we're doing an asynchronous (same-thread) sampling.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a14cf6b742de
Remove lock when profiling current thread in profiler_suspend_and_sample_thread - r=canaltinova

Comment 3

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/a14cf6b742de