using pthread_cond_broadcast with no mutex or waiting thread?

Question

Assuming some pthread_cond_t condvar; properly initialized with pthread_cond_init am I allowed to pthread_cond_broadcast it without any mutex locked and thread blocked with pthread_cond_timedwait on it?

I tend to understand that it is possible (with a well defined "no-op" behavior), but I am not entirely sure. This is how I am understanding

The pthread_cond_signal() and pthread_cond_broadcast() functions have no effect if there are no threads currently blocked on cond.

My scenario is a weird case where no thread is calling pthread_cond_timedwait on that condvar, but I don't want to special-case and avoid the broadcast. So the only thread using that condvar is the one calling pthread_cond_broadcast (in other words, the cond var is essentially useless in such case, but I try to avoid duplicating code...).

PS. My OS is Linux/Debian with GNU libc, but I prefer a general confirmation about POSIX standard. And Calling pthread_cond_signal without locking mutex is not the same question.

http://stackoverflow.com/questions/4544234/calling-pthread-cond-signal-without-locking-mutex — Mat, Apr 19 '16 at 11:24
That is not the same question. There is only one thread involved on that condvar. — Basile Starynkevitch, Apr 19 '16 at 11:25
Then your scenario makes no sense to me, and the answers there already say it's "ok" to broadcast outside a mutex. — Mat, Apr 19 '16 at 11:32

using pthread_cond_broadcast with no mutex or waiting thread?

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