PTHREAD_MUTEX_GETPRIOCEILING(3)

NAME
pthread_mutex_getprioceiling, pthread_mutex_setprioceiling - get or set the priority ceiling of a mutex

LIBRARY
libpthread

SYNOPSIS
#include <pthread.h>
int
pthread_mutex_getprioceiling(const pthread_mutex_t * restrict mutex, int * restrict prioceiling);
int
pthread_mutex_setprioceiling(pthread_mutex_t * restrict mutex, int prioceiling, int * restrict old_ceiling);

DESCRIPTION
The pthread_mutex_getprioceiling() function shall return the current priority ceiling of the mutex.

The pthread_mutex_setprioceiling() function shall either lock the mutex if it is unlocked, or block until it can successfully lock the mutex, then it shall change the mutex's priority ceiling and release the mutex. When the change is successful, the previous value of the priority ceiling shall be returned in old_ceiling. The process of locking the mutex need not adhere to the priority protect protocol. If the pthread_mutex_setprioceiling() function fails, the mutex priority ceiling shall not be changed.

RETURN VALUES
If successful, these functions return 0. Otherwise, an error number is returned to indicate the error.

ERRORS
The pthread_mutex_getprioceiling() and pthread_mutex_setprioceiling() functions will fail if:

[EINVAL]
    The priority requested by prioceiling is out of range; or the value specified by mutex does not refer to a currently existing mutex.

[EPERM]
    The caller does not have the privilege to perform the operation.

SEE ALSO
pthread_mutex_destroy(3), pthread_mutex_init(3), pthread_mutex_lock(3), pthread_mutex_timedlock(3), pthread_mutex_trylock(3), pthread_mutex_unlock(3)