PTHREAD_RWLOCKATTR_GETPSHARED(P) POSIX Programmer's Manual PTHREAD_RWLOCKATTR_GETPSHARED(P)
pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get and set the
process-shared attribute of the read-write lock attributes object
int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *
restrict attr, int *restrict pshared);
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
The pthread_rwlockattr_getpshared() function shall obtain the value of the process-shared
attribute from the initialized attributes object referenced by attr. The pthread_rwlock-
attr_setpshared() function shall set the process-shared attribute in an initialized
attributes object referenced by attr.
The process-shared 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 process-shared 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
process-shared 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 implementation-defined.
Upon successful completion, the pthread_rwlockattr_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_rwlockattr_setpshared() function shall return zero; otherwise,
an error number shall be returned to indicate the error.
The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions may fail
EINVAL The value specified by attr is invalid.
The pthread_rwlockattr_setpshared() function may fail if:
EINVAL The new value specified for the attribute is outside the range of legal values for
These functions shall not return an error code of [EINTR].
The following sections are informative.
pthread_rwlock_destroy() , pthread_rwlockattr_destroy() , pthread_rwlockattr_init() , the
Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h>
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 PTHREAD_RWLOCKATTR_GETPSHARED(P)