Re: [PATCH 0/3] MR5237: Use futexes on macOS for thread-ID alerts.

[Brendan Shanks (＠bshanks)]

Brendan Shanks (@bshanks) commented about dlls/ntdll/unix/sync.c:
> -
>    {
> -
>        errno = ETIMEDOUT;
> -
>        return -1;
> -
>    }
> -
>    return __ulock_wait( UL_COMPARE_AND_WAIT, (void *)addr, (uint64_t)val, us_timeout );
> - }
> -
> - return __ulock_wait( UL_COMPARE_AND_WAIT, (void *)addr, (uint64_t)val, 0 );
>
> +}
> -
>
> +static inline int futex_wake( const LONG *addr, int val )
> +{
> - return __ulock_wake( UL_COMPARE_AND_WAIT, (void *)addr, (uint64_t)val );
>
> +}
> -
>
> +#endif /* __APPLE__ */

These APIs are being publicly added to macOS 14.4 (`/usr/include/os/os_sync_wait_on_address.h` in Xcode 15.3, set for release any day now). Could this be implemented using that API, but use a fallback implementation (implemented with the private ulock APIs) when not building against/running on 14.4?