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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
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_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.
       These functions shall not return an error code of [EINTR].
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       If an implementation detects that the value specified  by  the  barrier
       argument  to pthread_barrier_destroy() does not refer to an initialized
       barrier object, it is recommended that the  function  should  fail  and
       report an [EINVAL] error.
       If an implementation detects that the value specified by the attr argu-
       ment to pthread_barrier_init() does not refer to an initialized barrier
       attributes  object, it is recommended that the function should fail and
       report an [EINVAL] error.
       If an implementation detects that the value specified  by  the  barrier
       argument  to pthread_barrier_destroy() or pthread_barrier_init() refers
       to a barrier that is in use (for example, in  a  pthread_barrier_wait()
       call)  by  another  thread,  or detects that the value specified by the
       barrier argument to pthread_barrier_init() refers to  an  already  ini-
       tialized  barrier  object,  it  is recommended that the function should
       fail and report an [EBUSY] error.
FUTURE DIRECTIONS
       None.
SEE ALSO
       pthread_barrier_wait()
       The Base Definitions volume of POSIX.1-2008, <pthread.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) 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.unix.org/online.html .
       Any  typographical  or  formatting  errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files  to  man page format. To report such errors, see https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013          PTHREAD_BARRIER_DESTROY(3P)