NetBSD-5.0.2/lib/libpthread/pthread_cond_broadcast.3

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.\" $FreeBSD: src/lib/libpthread/man/pthread_cond_broadcast.3,v 1.11 2002/09/16 19:29:28 mini Exp $
.\"
.Dd May 26, 2008
.Dt PTHREAD_COND_BROADCAST 3
.Os
.Sh NAME
.Nm pthread_cond_broadcast ,
.Nm pthread_cond_signal
.Nd unblock one or all threads waiting on a condition variable
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_cond_broadcast "pthread_cond_t *cond"
.Ft int
.Fn pthread_cond_signal "pthread_cond_t *cond"
.Sh DESCRIPTION
The
.Fn pthread_cond_broadcast
function unblocks all threads waiting for the condition variable
.Fa cond .
If no threads are waiting on
.Fa cond ,
the
.Fn pthread_cond_broadcast
function has no effect.
.Pp
The
.Fn pthread_cond_signal
function unblocks one thread waiting for the condition variable
.Fa cond .
If no threads are waiting on
.Fa cond ,
the
.Fn pthread_cond_signal
function has no effect.
.Pp
When calling
.Fn pthread_cond_wait
and/or
.Fn pthread_cond_timedwait ,
a temporary binding is established between the condition variable
.Fa cond
and a caller-supplied mutex.
.Pp
The same mutex must be held while calling
.Fn pthread_cond_broadcast
and
.Fn pthread_cond_signal .
Neither function enforces this requirement, but if the mutex is not
held the resulting behaviour is undefined.
.Sh RETURN VALUES
If successful, the
.Fn pthread_cond_broadcast
and
.Fn pthread_cond_signal
functions will return zero, otherwise an error number will be returned
to indicate the error.
.Sh ERRORS
.Fn pthread_cond_broadcast
and
.Fn pthread_cond_signal
may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa cond
is invalid.
.El
.Sh SEE ALSO
.Xr pthread_cond_destroy 3 ,
.Xr pthread_cond_init 3 ,
.Xr pthread_cond_timedwait 3 ,
.Xr pthread_cond_wait 3
.Sh STANDARDS
.Fn pthread_cond_broadcast
and
.Fn pthread_cond_signal
conform to
.St -p1003.1-96 .