pthread_mutex_getprioceiling(3T)										  pthread_mutex_getprioceiling(3T)

NAME

       pthread_mutex_getprioceiling(), pthread_mutex_setprioceiling() - get or set the prioceiling of a mutex.

SYNOPSIS

PARAMETERS

	      mutex	Pointer to the mutex whose prioceiling attribute is to be set/retrieved.

	      prioceiling
			This  parameter either points to the memory location where the prioceiling attribute of mutex is to be returned (get func-
			tion) or specifies the new value of the prioceiling attribute for mutex (set function).

	      old_ceiling
			This parameter points to the memory location where the old prioceiling attribute of mutex is to be returned (set  function
			only).

DESCRIPTION

       The  function  will first lock mutex.  If the mutex is currently locked, the calling thread will block until the mutex can be locked.  Once
       the mutex has been locked, the prioceiling attribute of mutex will be changed to the value specified in the prioceiling parameter and mutex
       will be unlocked.  The old priority ceiling for the mutex will be returned in old_prioceiling.

       The function returns the current value of the prioceiling attribute for mutex in the prioceiling parameter.

       Be sure to check for the definition of before using these functions.  Not all systems will support these functions.

RETURN VALUE

       Upon successful completion, and return zero. Otherwise, an error number is returned to indicate the error (the variable is not set).

ERRORS

       If any of the following occur, the and functions return the corresponding error number:

	      is not defined and these functions are not supported.

       For each of the following conditions, if the condition is detected, the and functions return the corresponding error number:

	      The priority value
			     prioceiling is not a legal value.

	      mutex	     is not a valid mutex.

	      The prioceiling protocol is not supported for mutexes.

	      The caller does not have the appropriate privileges to
			     change priority ceiling for mutex.

	      mutex	     parameter points to an illegal address.

AUTHOR

       and were derived from the IEEE POSIX P1003.1c standard.

SEE ALSO

       pthread_create(3T),	  pthread_mutex_init(3T),	 pthread_mutexattr_setprioceiling(3T),	     pthread_mutexattr_getprioceiling(3T),
       pthread_mutex_lock(3T), pthread_mutex_trylock(3T), pthread_mutex_unlock(3T).

STANDARDS CONFORMANCE

								  Pthread Library				  pthread_mutex_getprioceiling(3T)