pthread_barrier_wait(3c) [opensolaris man page]

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 5.11							    30 Jan 2004 					  pthread_barrier_wait(3C)

Check Out this Related Man Page

PTHREAD_BARRIER(3)					   BSD Library Functions Manual 					PTHREAD_BARRIER(3)

NAME

     pthread_barrier_destroy, pthread_barrier_init, pthread_barrier_wait -- destroy, initialize or wait on a barrier object

LIBRARY

     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

     #include <pthread.h>

     int
     pthread_barrier_destroy(pthread_barrier_t *barrier);

     int
     pthread_barrier_init(pthread_barrier_t *barrier, const pthread_barrierattr_t *attr, unsigned count);

     int
     pthread_barrier_wait(pthread_barrier_t *barrier);

DESCRIPTION

     The pthread_barrier_init() function will initialize barrier with attributes specified in attr, or if it is NULL, with default attributes.
     The number of threads that must call pthread_barrier_wait() before any of the waiting threads can be released is specified by count.  The
     pthread_barrier_destroy() function will destroy barrier and release any resources that may have been allocated on its behalf.

     The pthread_barrier_wait() function will synchronize calling threads at barrier.  The threads will be blocked from making further progress
     until a sufficient number of threads calls this function.	The number of threads that must call it before any of them will be released is
     determined by the count argument to pthread_barrier_init().  Once the threads have been released the barrier will be reset.

IMPLEMENTATION NOTES

     In both N:M Threading Library (libkse, -lkse) and 1:1 Threading Library (libthr, -lthr) the PTHREAD_BARRIER_SERIAL_THREAD return value will
     always be returned by the last thread to reach the barrier.

RETURN VALUES

     If successful, both pthread_barrier_destroy() and pthread_barrier_init() will return zero.  Otherwise, an error number will be returned to
     indicate the error.  If the call to pthread_barrier_wait() is successful, all but one of the threads will return zero.  That one thread will
     return PTHREAD_BARRIER_SERIAL_THREAD.  Otherwise, an error number will be returned to indicate the error.

     None of these functions will return EINTR.

ERRORS

     The pthread_barrier_destroy() function will fail if:

     [EBUSY]		An attempt was made to destroy barrier while it was in use.

     The pthread_barrier_destroy() and pthread_barrier_wait() functions may fail if:

     [EINVAL]		The value specified by barrier is invalid.

     The pthread_barrier_init() function will fail if:

     [EAGAIN]		The system lacks resources, other than memory, to initialize barrier.

     [EINVAL]		The count argument is less than 1.

     [ENOMEM]		Insufficient memory to initialize barrier.

SEE ALSO

     pthread_barrierattr(3)

HISTORY

     The pthread_barrier_destroy(), pthread_barrier_init() and pthread_barrier_wait() functions first appeared in N:M Threading Library (libkse,
     -lkse) in FreeBSD 5.2, and in 1:1 Threading Library (libthr, -lthr) in FreeBSD 5.3.

BSD
								 February 19, 2004							       BSD

Linux and UNIX Man Pages

pthread_barrier_wait(3c) [opensolaris man page]

Check Out this Related Man Page