Re: Resuming work on new semaphore

[Alexander Monakov <amonakov@ispras.ru>]

On Sun, 5 Apr 2015, Rich Felker wrote:
> So if cancellation was pending _before_ the call to sem_wait, then
> sem_wait has to honor it. But there is no requirement that entry to
> the sem_wait function be "atomic" with becoming a waiter on the
> semaphore, and of course this is impossible to satisfy or even
> specify.

Thanks!

One other thing to consider.  In the absence of concurrent operations on the
semaphore, return value of sem_getvalue should be equal to the number of times
sem_trywait will indicate success when called repeatedly.  So if the
implementation performs post-stealing in trywait, it should return the higher
bound as semaphore value.  Likewise for timedwait.

Alexander