pthread_mutex_setprioceiling(3P)

NAME
     pthread_mutex_setprioceiling, pthread_mutex_getprioceiling - set/get a
     mutex's priority ceiling

C SYNOPSIS
     #include <pthread.h>

     int pthread_mutex_setprioceiling(pthread_mutex_t *mutex,
          int prioceiling, int *old_ceiling);

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

DESCRIPTION
     The pthread_mutex_getprioceiling() function returns the current priority
     ceiling of the named mutex.

     The pthread_mutex_setprioceiling() function acquires the named mutex,
     then changes the mutex's priority ceiling and releases the mutex.  The
     value of prioceiling must be between the values returned by
     sched_get_priority_min() and sched_get_priority_max(), inclusive.

     If successful, the previous value of the mutex priority ceiling is
     returned in old_ceiling.

DIAGNOSTICS
     If successful, the mutex protocol functions return zero; otherwise, an
     error number is returned:

     [EINVAL]       The priority specified by prioceiling is out of range.

     [EPERM]        The mutex was not initialized with the
                    PTHREAD_PRIO_PROTECT protocol attribute.

SEE ALSO
     pthread_mutexattr_setprotocol(3P), pthread_mutex_lock(3P),
     sched_get_priority_min(3C), sched_get_priority_max(3C).

NOTES
     Calls to pthread_mutex_setprioceiling() are not subject to the priority
     protect protocol.