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.
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.
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