Section: POSIX Programmer's Manual (3P)
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.
--- get and set the process-shared attribute of the read-write lock
int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t
*restrict attr, int *restrict pshared);
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
function shall obtain the value of the
attribute from the initialized attributes object referenced by
function shall set the
attribute in an initialized attributes object referenced by
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
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
attribute shall be PTHREAD_PROCESS_PRIVATE.
Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
The behavior is undefined if the value specified by the
does not refer to an initialized read-write lock attributes object.
Upon successful completion, the
function shall return zero and store the value of the
into the object referenced by the
parameter. Otherwise, an error number shall be returned to indicate the
If successful, the
function shall return zero; otherwise, an error number shall be
returned to indicate the error.
function may fail if:
The new value specified for the attribute is outside the range of legal
values for that attribute.
These functions shall not return an error code of
The following sections are informative.
The Base Definitions volume of POSIX.1-2008,
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
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