pthread_mutexattr_getpshared.txt

来自「Pthread lib库完整说明文档」· 文本 代码 · 共 84 行

pthread_mutexattr_getpshared Subroutine



Purpose

Returns the value of the process-shared attribute of a mutex attributes
object.

Note:	This subroutine is not implemented in AIX. It always returns
ENOSYS.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>

int pthread_mutexattr_getpshared (attr, pshared)
const pthread_mutexattr_t *attr;
int *pshared;

Description

The pthread_mutexattr_getpshared subroutine returns the value of the
process-shared attribute of the mutex attributes object attr. This
attribute specifies the process sharing of the mutex created with
this attributes object. It may have one of the following values:

PTHREAD_PROCESS_SHARED	Specifies that the mutex can be used by any
thread that has access to the memory where it is allocated, even if
these threads belong to different processes.

PTHREAD_PROCESS_PRIVATE	Specifies that the mutex shall only be used
by threads within the same process as the thread that created it.
This is the default value.

Note:	The pthread.h header file must be the first included file of
each source file using the threads library.

Parameters

attr	Specifies the mutex attributes object.

pshared	Points to where the pshared attribute value will be stored.

Return Values

Upon successful completion, the value of the pshared attribute is
returned via the pshared parameter, and 0 is returned. Otherwise,
an error code is returned.

Error Codes

The pthread_mutexattr_getpshared subroutine is unsuccessful if the
following is true:

EINVAL	The attr parameter is not valid.

ENOSYS	The process sharing POSIX option is not implemented.

Implementation Specifics

This subroutine is part of the Base Operating System (BOS) Runtime.

The implementation of this subroutine is dependent on the process
sharing POSIX option. The process sharing POSIX option is not implemented
in AIX.

Related Information

The pthread_mutexattr_setpshared subroutine, pthread_mutexattr_init
subroutine.

Advanced Attributes.

Threads Library Options and Threads Library Quick Reference.