pthread_barrier_wait(3C)				   Standard C Library Functions 				  pthread_barrier_wait(3C)

NAME

       pthread_barrier_wait - synchronize at a barrier

SYNOPSIS

       cc -mt [ flag... ] file... [ library... ]
       #include <pthread.h>

       int pthread_barrier_wait(pthread_barrier_t *barrier);

DESCRIPTION

       The  pthread_barrier_wait()  function  synchronizes  participating  threads at the barrier referenced by barrier. The calling thread blocks
       until the required number of threads have called pthread_barrier_wait() specifying the barrier.

       When the required number of threads have called pthread_barrier_wait() specifying the barrier, the  constant  PTHREAD_BARRIER_SERIAL_THREAD
       is  returned to one unspecified thread and 0 is returned to each of the remaining threads. At this point, the barrier is reset to the state
       it had as a result of the most recent pthread_barrier_init(3C) function that referenced it.

       The constant PTHREAD_BARRIER_SERIAL_THREAD is defined in  <pthread.h>  and  its	value  is  distinct  from  any	other  value  returned	by
       pthread_barrier_wait().

       The results are undefined if this function is called with an uninitialized barrier.

       If a signal is delivered to a thread blocked on a barrier, upon return from the signal handler the thread resumes waiting at the barrier if
       the barrier wait has not completed (that is, if the required number of threads have not arrived at the barrier during the execution of  the
       signal  handler); otherwise, the thread continues as normal from the completed barrier wait. Until the thread in the signal handler returns
       from it, it is unspecified whether other threads may proceed past the barrier once they have all reached it.

       A thread that has blocked on a barrier does not prevent any unblocked thread that is eligible to use the  same  processing  resources  from
       eventually making forward progress in its execution.

       Eligibility for processing resources is determined by the scheduling policy.

RETURN VALUES

       Upon  successful completion, the pthread_barrier_wait() function returns PTHREAD_BARRIER_SERIAL_THREAD for a single (arbitrary) thread syn-
       chronized at the barrier and 0 for each of the other threads. Otherwise, an error number is returned to indicate the error.

ERRORS

       The pthread_barrier_wait() function will fail if:

       EINVAL	       The value specified by barrier does not refer to an initialized barrier object.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       pthread_barrier_destroy(3C), attributes(5), standards(5)

SunOS 5.10							    30 Jan 2004 					  pthread_barrier_wait(3C)