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)

pthread_barrier_destroy(3C)				   Standard C Library Functions 			       pthread_barrier_destroy(3C)

NAME

       pthread_barrier_destroy, pthread_barrier_init - destroy and initialize a barrier object

SYNOPSIS

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

       int pthread_barrier_destroy(pthread_barrier_t *barrier);

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

DESCRIPTION

       The  pthread_barrier_destroy()  function  destroys  the	barrier  referenced by barrier and releases any resources used by the barrier. The
       effect of subsequent use of the barrier is undefined until the barrier is reinitialized	by  another  call  to  pthread_barrier_init().	An
       implementation  can  use this function to set barrier to an invalid value. The results are undefined if pthread_barrier_destroy() is called
       when any thread is blocked on the barrier, or if this function is called with an uninitialized barrier.

       The pthread_barrier_init() function allocates any resources required to use the barrier referenced by barrier and initializes  the  barrier
       with attributes referenced by attr. If attr is NULL, the default barrier attributes are used; the effect is the same as passing the address
       of a default barrier attributes object. The results are undefined if pthread_barrier_init() is called when any thread  is  blocked  on  the
       barrier	(that  is,  has not returned from the pthread_barrier_wait(3C) call). The results are undefined if a barrier is used without first
       being initialized. The results are undefined if pthread_barrier_init() is called specifying an already initialized barrier.

       The count argument specifies the number of threads that must call pthread_barrier_wait() before any of them successfully  return  from  the
       call. The value specified by count must be greater than 0.

       If the pthread_barrier_init() function fails, the barrier is not initialized and the contents of barrier are undefined.

       Only the object referenced by barrier can be used for performing synchronization. The result of referring to copies of that object in calls
       to pthread_barrier_destroy() or pthread_barrier_wait() is undefined.

RETURN VALUES

       Upon successful completion, these functions returns 0. Otherwise, an error number is returned to indicate the error.

ERRORS

       The pthread_barrier_init() function will fail if:

       EAGAIN	       The system lacks the necessary resources to initialize another barrier.

       EINVAL	       The value specified by count is equal to 0.

       ENOMEM	       Insufficient memory exists to initialize the barrier.

       The pthread_barrier_init() function may fail if:

       EBUSY	       The implementation has detected an attempt to destroy a barrier while it is in use (for example,  while	being  used  in  a
		       pthread_barrier_wait() call) by another thread.

       EINVAL	       The value specified by attr is invalid.

       The pthread_barrier_destroy() function may fail if:

       EBUSY	       The  implementation  has  detected  an  attempt to destroy a barrier while it is in use (for example, while being used in a
		       pthread_barrier_wait() call) by another thread.

       EINVAL	       The value specified by barrier is invalid.

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

SunOS 5.10							    30 Jan 2004 				       pthread_barrier_destroy(3C)