pthread_cond_signal(3thr)pthread_cond_signal(3thr)Namepthread_cond_signal - Wakes one thread that is waiting on a condition
variable.
Syntax
#include <pthread.h>
int pthread_cond_signal (cond)
pthread_cond_t *cond;
Arguments
cond Condition variable signaled.
Description
This routine wakes one thread waiting on a condition variable. Calling
this routine implies that data guarded by the associated mutex has
changed so that it might be possible for a single waiting thread to
proceed. Call this routine when any thread waiting on the specified
condition variable might find its predicate true, but only one thread
should proceed.
The scheduling policy determines which thread is awakened. For poli‐
cies SCHED_FIFO and SCHED_RR, a blocked thread is chosen in priority
order, using FIFO (First In, First Out) within priorities.
Call this routine when the associated mutex is either locked or
unlocked.
Return Values
If an error condition occurs, this routine returns -1 and sets errno to
the corresponding error value. Possible return values are as follows.
Return Error Description
0 Successful comple‐
tion.
-1 [EINVAL] The value specified
by cond is invalid.
pthread_cond_signal(3thr)