Re: [PATCH v4 00/15] Add futex2 syscalls

Florian Weimer
2021-06-08T18:19:41Z

* Adhemerval Zanella:

> Also currently we don't have a specific usage. The proposed patch to
> add the 'pthread_mutex_lock_any' and 'pthreada_timedlock_any' [3]
> also did not gave much detail in realword usages or how it can be
> leveraged.

The current rwlock implementation in glibc uses a torn 32-bit futex read
which is part of an atomically updated 64-bit word. That's just really,
really ugly, and I suspect we could make that go away with futex2.

Thanks,
Florian