Replace semaphore_t on dispatch_semaphore_t on macOS

[pavelkumbrasev]

Signed-off-by: pavelkumbrasev [email protected]

Description

To enable ThreadSanitizer on APPLE (basically on macOS) replaced semaphore_t on dispatch_semaphore_t which supports via ThreadSanitizer. In accordance to scenarios where and how we use semaphore the performance should not change, but still need to prove this.

Fixes # - #358

• [x] - git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details)

Type of change

Choose one or multiple, leave empty if none of the other choices apply

Add a respective label(s) to PR if you have permissions

• [ ] bug fix - change that fixes an issue
• [x] new feature - change that adds functionality
• [ ] tests - change in tests
• [ ] infrastructure - change in infrastructure and CI
• [ ] documentation - documentation update

Tests

• [ ] added - required for new features and some bug fixes
• [x] not needed

Documentation

• [ ] updated in # - add PR number
• [ ] needs to be updated
• [x] not needed

Breaks backward compatibility

• [ ] Yes
• [x] No
• [ ] Unknown

Notify the following users

@phprus

Other information

[akukanov]

Does this change introduce any new dependencies for either compilation/link time or execution time which need to be documented?

Do we know that the dispatch semaphore has no spurious wakeups?

[pavelkumbrasev]

Does this change introduce any new dependencies for either compilation/link time or execution time which need to be documented?

Do we know that the dispatch semaphore has no spurious wakeups?

I currently researching both questions. For now I checked that dispatch_semaphore_t introduced with macOS 10.6. Also I did not observe any new flags during the compilation. (I compiled example from #358 using dispatch_semaphore_t without any additional flags)

[pavelkumbrasev]

It seems that from dispatch_semaphore_t documentation there should not be spurious wakeups during wait calls. Also from the implementation point of view they have similar while loop on case DISPATCH_TIME_FOREVER.

[natale-p]

Tested on mac os 12.6, and I can easily see that I don't have many false positives as I had without this patch.

[natale-p]

Hello, any news on this PR? Can it be merged?

[pavelkumbrasev]

Hi @natale-p, we are going to merge it after we will satisfy all test requirements for it. (I hope it will be soon)