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PTHREAD_BARRIER_DESTROY(3P)POSIX Programmer's ManuaPTHREAD_BARRIER_DESTROY(3P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       pthread_barrier_destroy, pthread_barrier_init - destroy and  initialize
       a barrier object (ADVANCED REALTIME THREADS)
SYNOPSIS
       #include <pthread.h>
       int pthread_barrier_destroy(pthread_barrier_t *barrier);
       int pthread_barrier_init(pthread_barrier_t *restrict barrier,
              const pthread_barrierattr_t *restrict attr, unsigned count);

DESCRIPTION
       The pthread_barrier_destroy() function shall destroy the barrier refer-
       enced by barrier and release 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  imple-
       mentation may 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  shall  allocate  any   resources
       required  to use the barrier referenced by barrier and shall initialize
       the barrier with attributes referenced by attr.  If attr is  NULL,  the
       default  barrier  attributes  shall  be 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_bar-
       rier_wait() call). The results are undefined if a barrier is used with-
       out first being initialized. The results are undefined if  pthread_bar-
       rier_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 zero.
       If  the pthread_barrier_init() function fails, the barrier shall not be
       initialized and the contents of barrier are undefined.
       Only the object referenced by barrier may be used for  performing  syn-
       chronization. The result of referring to copies of that object in calls
       to pthread_barrier_destroy() or pthread_barrier_wait() is undefined.
RETURN VALUE
       Upon successful completion, these functions shall return  zero;  other-
       wise, an error number shall be returned to indicate the error.
ERRORS
       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.

       The pthread_barrier_init() function shall fail if:
       EAGAIN The  system  lacks the necessary resources to initialize another
              barrier.
       EINVAL The value specified by count is equal to zero.
       ENOMEM Insufficient memory exists to initialize the barrier.

       The pthread_barrier_init() function may fail if:
       EBUSY  The implementation has detected an  attempt  to  reinitialize  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.

       These functions shall not return an error code of [EINTR].
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       The pthread_barrier_destroy() and pthread_barrier_init() functions  are
       part of the Barriers option and need not be provided on all implementa-
       tions.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       pthread_barrier_wait(),    the    Base    Definitions     volume     of
       IEEE Std 1003.1-2001, <pthread.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003          PTHREAD_BARRIER_DESTROY(3P)