pthread_mutexattr_getprioceiling.txt

Pthread lib库完整说明文档

pthread_mutexattr_getprioceiling Subroutine



Purpose

Returns the value of the prioceiling attribute of a mutex attributes
object.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>

int pthread_mutexattr_getprioceiling (attr, prioceiling)
const pthread_mutexattr_t *attr;
int *prioceiling;

Description

The pthread_mutexattr_getprioceiling subroutine returns the value
of the prioceiling attribute of the mutex attributes object attr.
This attribute specifies the priority ceiling of the mutex created
with this attributes object, used in the priority protection protocol
to prevent priority inversions. It has no meaning if the mutex uses
another protocol.

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.

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

Return Values

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

Error Codes

The pthread_mutexattr_getprioceiling subroutine is unsuccessful if
the following is true:

EINVAL	The attr parameter is not valid.

ENOSYS	The priority protection POSIX option is not implemented.

EPERM	The calling thread does not have sufficient privilege to perform
the operation.

Implementation Specifics

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

The implementation of this subroutine is dependent on the priority
protection POSIX option. The priority protection POSIX option is not
implemented in the current version of AIX.

Related Information

The pthread_mutexattr_setprioceiling subroutine, pthread_mutexattr_init
subroutine, pthread_mutex_getprioceiling subroutine.

Synchronization Scheduling.

Threads Library Options and Threads Library Quick Reference.