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 ALSOpthread_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)
