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.\" $FreeBSD: head/share/man/man3/pthread_cond_timedwait.3 233648 2012-03-29 05:02:12Z eadler $
.\"
.Dd May 9, 2010
.Dt PTHREAD_COND_TIMEDWAIT 3
.Os
.Sh NAME
.Nm pthread_cond_timedwait
.Nd "wait on a condition variable for a specific amount of time"
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_cond_timedwait "pthread_cond_t *cond" "pthread_mutex_t *mutex" "const struct timespec *abstime"
.Sh DESCRIPTION
The
.Fn pthread_cond_timedwait
function atomically blocks the current thread waiting on the condition
variable specified by
.Fa cond ,
and releases the mutex specified by
.Fa mutex .
The waiting thread unblocks only after another thread calls
.Xr pthread_cond_signal 3 ,
or
.Xr pthread_cond_broadcast 3
with the same condition variable, or if the system time reaches the
time specified in
.Fa abstime ,
and the current thread reacquires the lock on
.Fa mutex .
.Pp
The clock used to measure
.Fa abstime
can be specified during creation of the condition variable using
.Xr pthread_condattr_setclock 3 .
.Sh RETURN VALUES
If successful, the
.Fn pthread_cond_timedwait
function will return zero.
Otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
The
.Fn pthread_cond_timedwait
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa cond ,
.Fa mutex
or
.Fa abstime
is invalid.
.It Bq Er ETIMEDOUT
The system time has reached or exceeded the time specified in
.Fa abstime .
.It Bq Er EPERM
The specified
.Fa mutex
was not locked by the calling thread.
.El
.Sh SEE ALSO
.Xr pthread_cond_broadcast 3 ,
.Xr pthread_cond_destroy 3 ,
.Xr pthread_cond_init 3 ,
.Xr pthread_cond_signal 3 ,
.Xr pthread_cond_wait 3 ,
.Xr pthread_condattr_setclock 3
.Sh STANDARDS
The
.Fn pthread_cond_timedwait
function conforms to
.St -p1003.1-96 .