.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "PTHREAD_RWLOCKATTR_GETPSHARED" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" pthread_rwlockattr_getpshared 
.SH 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.
.SH NAME
pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared \- get
and set the process\-shared attribute of the
read\-write lock attributes object
.SH SYNOPSIS
.LP
\fB#include <pthread.h>
.br
.sp
int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *
.br
\ \ \ \ \ \  restrict\fP \fIattr\fP\fB, int *restrict\fP \fIpshared\fP\fB);
.br
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t\fP \fI*attr\fP\fB,
.br
\ \ \ \ \ \  int\fP \fIpshared\fP\fB); \fP
\fB
.br
\fP
.SH DESCRIPTION
.LP
The \fIpthread_rwlockattr_getpshared\fP() function shall obtain the
value of the \fIprocess-shared\fP attribute from the
initialized attributes object referenced by \fIattr\fP. The \fIpthread_rwlockattr_setpshared\fP()
function shall set the
\fIprocess-shared\fP attribute in an initialized attributes object
referenced by \fIattr\fP.
.LP
The \fIprocess-shared\fP attribute shall be set to PTHREAD_PROCESS_SHARED
to permit a read-write lock to be operated upon by
any thread that has access to the memory where the read-write lock
is allocated, even if the read-write lock is allocated in memory
that is shared by multiple processes. If the \fIprocess-shared\fP
attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock shall
only be operated upon by threads created within the same process as
the thread that initialized the read-write lock; if threads of
differing processes attempt to operate on such a read-write lock,
the behavior is undefined. The default value of the
\fIprocess-shared\fP attribute shall be PTHREAD_PROCESS_PRIVATE.
.LP
Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-defined.
.SH RETURN VALUE
.LP
Upon successful completion, the \fIpthread_rwlockattr_getpshared\fP()
function shall return zero and store the value of the
\fIprocess-shared\fP attribute of \fIattr\fP into the object referenced
by the \fIpshared\fP parameter. Otherwise, an error
number shall be returned to indicate the error.
.LP
If successful, the \fIpthread_rwlockattr_setpshared\fP() function
shall return zero; otherwise, an error number shall be
returned to indicate the error.
.SH ERRORS
.LP
The \fIpthread_rwlockattr_getpshared\fP() and \fIpthread_rwlockattr_setpshared\fP()
functions may fail if:
.TP 7
.B EINVAL
The value specified by \fIattr\fP is invalid.
.sp
.LP
The \fIpthread_rwlockattr_setpshared\fP() function may fail if:
.TP 7
.B EINVAL
The new value specified for the attribute is outside the range of
legal values for that attribute.
.sp
.LP
These functions shall not return an error code of [EINTR].
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
None.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIpthread_rwlock_destroy\fP(), \fIpthread_rwlockattr_destroy\fP(),
\fIpthread_rwlockattr_init\fP(), the Base Definitions volume of
IEEE\ Std\ 1003.1-2001, \fI<pthread.h>\fP
.SH 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 .