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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH PTHREAD_COND_SIGNAL 3C "Mar 23, 2005" .SH NAME pthread_cond_signal, pthread_cond_broadcast \- signal or broadcast a condition .SH SYNOPSIS .LP .nf cc -mt [ \fIflag\fR... ] \fIfile\fR... -lpthread [ \fIlibrary\fR... ] #include <pthread.h> \fBint\fR \fBpthread_cond_signal\fR(\fBpthread_cond_t *\fR\fIcond\fR); .fi .LP .nf \fBint\fR \fBpthread_cond_broadcast\fR(\fBpthread_cond_t *\fR\fIcond\fR); .fi .SH DESCRIPTION .sp .LP These two functions are used to unblock threads blocked on a condition variable. .sp .LP The \fBpthread_cond_signal()\fR call unblocks at least one of the threads that are blocked on the specified condition variable \fIcond\fR (if any threads are blocked on \fIcond\fR). .sp .LP The \fBpthread_cond_broadcast()\fR call unblocks all threads currently blocked on the specified condition variable \fIcond\fR. .sp .LP If more than one thread is blocked on a condition variable, the scheduling policy determines the order in which threads are unblocked. When each thread unblocked as a result of a \fBpthread_cond_signal()\fR or \fBpthread_cond_broadcast()\fR returns from its call to \fBpthread_cond_wait()\fR or \fBpthread_cond_timedwait()\fR, the thread owns the mutex with which it called \fBpthread_cond_wait()\fR or \fBpthread_cond_timedwait()\fR. The thread(s) that are unblocked contend for the mutex according to the scheduling policy (if applicable), and as if each had called \fBpthread_mutex_lock()\fR. .sp .LP The \fBpthread_cond_signal()\fR or \fBpthread_cond_broadcast()\fR functions may be called by a thread whether or not it currently owns the mutex that threads calling \fBpthread_cond_wait()\fR or \fBpthread_cond_timedwait()\fR have associated with the condition variable during their waits; however, if predictable scheduling behavior is required, then that mutex is locked by the thread calling \fBpthread_cond_signal()\fR or \fBpthread_cond_broadcast()\fR. .sp .LP The \fBpthread_cond_signal()\fR and \fBpthread_cond_broadcast()\fR functions have no effect if there are no threads currently blocked on \fIcond\fR. .SH RETURN VALUES .sp .LP If successful, the \fBpthread_cond_signal()\fR and \fBpthread_cond_broadcast()\fR functions return \fB0\fR. Otherwise, an error number is returned to indicate the error. .SH ERRORS .sp .LP The \fBpthread_cond_signal()\fR and \fBpthread_cond_broadcast()\fR function may fail if: .sp .ne 2 .na \fB\fBEINVAL\fR\fR .ad .RS 10n The value \fIcond\fR does not refer to an initialized condition variable. .RE .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ Interface Stability Standard _ MT-Level MT-Safe .TE .SH SEE ALSO .sp .LP \fBpthread_cond_init\fR(3C), \fBpthread_cond_wait\fR(3C), \fBpthread_cond_timedwait\fR(3C), \fBattributes\fR(5), \fBcondition\fR(5), \fBstandards\fR(5)