PTHREAD_BARRIER_DESTROY
Section: POSIX Programmer's Manual (3P)
Updated: 2013
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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 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.
Only the object referenced by
barrier
may 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 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.1-2008,
<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
Electrical 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.kernel.org/doc/man-pages/reporting_bugs.html .
Index
- PROLOG
-
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-