pthread_mutex_getprioceiling Subroutine



Purpose

Returns the current value of the prioceiling attribute of a mutex.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>

int pthread_mutex_getprioceiling (mutex, prioceiling)
pthread_mutex_t *mutex;
int *prioceiling;

Description

The pthread_mutex_getprioceiling subroutine returns the current value
of the prioceiling attribute of the mutex mutex. This attribute specifies
the priority ceiling of the mutex, 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

mutex	Specifies the target mutex.

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

Return Values

Upon successful completion, the current 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_mutex_getprioceiling subroutine is unsuccessful if the
following is true:

EINVAL	The mutex parameter is not valid.

ENOSYS	The priority protection POSIX option is not implemented.

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

ESRCH	The mutex mutex does not exist.

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_mutex_setprioceiling subroutine, pthread_mutexattr_getprioceiling
subroutine.

Synchronization Scheduling.

Threads Library Options.

Threads Library Quick Reference.