NAME
pthread_barrierattr_getpshared, pthread_barrierattr_setpshared - get
and set the process-shared attribute of the barrier attributes object
(ADVANCED REALTIME THREADS)
SYNOPSIS
#include <pthread.h>
int pthread_barrierattr_getpshared(const pthread_barrierattr_t *
restrict attr, int *restrict pshared);
int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr,
int pshared);
DESCRIPTION
The pthread_barrierattr_getpshared() function shall obtain the value of
the process-shared attribute from the attributes object referenced by
attr. The pthread_barrierattr_setpshared() function shall set the
process-shared attribute in an initialized attributes object referenced
by attr.
The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit
a barrier to be operated upon by any thread that has access to the
memory where the barrier is allocated. If the process-shared attribute
is PTHREAD_PROCESS_PRIVATE, the barrier shall only be operated upon by
threads created within the same process as the thread that initialized
the barrier; if threads of different processes attempt to operate on
such a barrier, the behavior is undefined. The default value of the
attribute shall be PTHREAD_PROCESS_PRIVATE. Both constants
PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE are defined in
<pthread.h>.
Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-defined.
RETURN VALUE
If successful, the pthread_barrierattr_getpshared() function shall
return zero and store the value of the process-shared attribute of attr
into the object referenced by the pshared parameter. Otherwise, an
error number shall be returned to indicate the error.
If successful, the pthread_barrierattr_setpshared() function shall
return zero; otherwise, an error number shall be returned to indicate
the error.
ERRORS
These functions may fail if:
EINVAL The value specified by attr is invalid.
The pthread_barrierattr_setpshared() function may fail if:
EINVAL The new value specified for the process-shared attribute is not
one of the legal values PTHREAD_PROCESS_SHARED or
PTHREAD_PROCESS_PRIVATE.
These functions shall not return an error code of [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The pthread_barrierattr_getpshared() and
pthread_barrierattr_setpshared() functions are part of the Barriers
option and need not be provided on all implementations.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_barrier_destroy() , pthread_barrierattr_destroy() ,
pthread_barrierattr_init() , 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 .