The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.
NAME
pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and set the process-shared attribute
SYNOPSIS
[THR TSH]
#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); ![[Option End]](../images/opt-end.gif)
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>
CHANGE HISTORY
First released in Issue 5. Included for alignment with the POSIX Threads Extension.
Issue 6
The pthread_mutexattr_getpshared() and pthread_mutexattr_setpshared() functions are marked as part of the Threads
and Thread Process-Shared Synchronization options.
The restrict keyword is added to the pthread_mutexattr_getpshared() prototype for alignment with the
ISO/IEC 9899:1999 standard.
End of informative text.
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POSIX ® is a registered Trademark of The IEEE.
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