NAME
pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and
set the process-shared attribute
SYNOPSIS
#include <pthread.h>
int pthread_mutexattr_getpshared(const pthread_mutexattr_t *
restrict attr, int *restrict pshared);
int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
int pshared);
DESCRIPTION
The pthread_mutexattr_getpshared() function shall obtain the value of
the process-shared attribute from the attributes object referenced by
attr. The pthread_mutexattr_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 mutex to be operated upon by any thread that has access to the memory
where the mutex is allocated, even if the mutex is allocated in memory
that is shared by multiple processes. If the process-shared attribute
is PTHREAD_PROCESS_PRIVATE, the mutex shall only be operated upon by
threads created within the same process as the thread that initialized
the mutex; if threads of differing processes attempt to operate on such
a mutex, the behavior is undefined. The default value of the attribute
shall be PTHREAD_PROCESS_PRIVATE.
RETURN VALUE
Upon successful completion, pthread_mutexattr_setpshared() shall return
zero; otherwise, an error number shall be returned to indicate the
error.
Upon successful completion, pthread_mutexattr_getpshared() 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.
ERRORS
The pthread_mutexattr_getpshared() and pthread_mutexattr_setpshared()
functions may fail if:
EINVAL The value specified by attr is invalid.
The pthread_mutexattr_setpshared() function may fail if:
EINVAL 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 [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_cond_destroy() , pthread_create() , pthread_mutex_destroy() ,
pthread_mutexattr_destroy() , 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 .