PTHREAD_BARRIER_DESTROY(3) POSIX Programmer's ManualPTHREAD_BARRIER_DESTROY(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

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
       referenced 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
       implementation 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__barrier__wait() 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 zero.

       If the pthread__barrier__init() function fails, the barrier shall not be
       initialized and the contents of barrier are undefined.

       See Section 2.9.9, Synchronization Object Copies and Alternative
       Mappings for further requirements.

RETURN VALUE
       Upon successful completion, these functions shall return zero;
       otherwise, 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
       argument 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
       initialized 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.1-2017, <pthread.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       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.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017           PTHREAD_BARRIER_DESTROY(3)
