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.Dd January 30, 2003
.Dt PTHREAD_BARRIER_WAIT 3
.Os
.Sh NAME
.Nm pthread_barrier_wait
.Nd wait for a barrier
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_barrier_wait "pthread_barrier_t *barrier"
.Sh DESCRIPTION
The
.Fn pthread_barrier_wait
function causes the current thread to wait on the barrier specified.
Once as many threads as specified by the
.Fa count
parameter to the corresponding
.Fn pthread_barrier_init
call have called
.Fn pthread_barrier_wait ,
all threads will wake up, return from their respective
.Fn pthread_barrier_wait
calls and continue execution.
.Sh RETURN VALUES
If successful,
.Fn pthread_barrier_wait
will return zero for all waiting threads except for one.
One thread will receive status
.Dv PTHREAD_BARRIER_SERIAL_THREAD ,
which is intended to indicate that this thread may be used to update
shared data.
It is the responsibility of this thread to insure the visibility
and atomicity of any updates to shared data with respect to the
other threads participating in the barrier.
In the case of failure, an error value will be returned.
.Sh ERRORS
.Fn pthread_barrier_wait
may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa barrier
is invalid.
.El
.Sh SEE ALSO
.Xr pthread_barrier_destroy 3 ,
.Xr pthread_barrier_init 3 ,
.Xr pthread_barrierattr_destroy 3 ,
.Xr pthread_barrierattr_init 3
.Sh STANDARDS
.Fn pthread_barrier_wait
conforms to
.St -p1003.1-2001 .