NAME

       pthread_mutexattr_getprioceiling,  pthread_mutexattr_setprioceiling  -  get  and  set  the
       prioceiling attribute of the mutex attributes object (REALTIME THREADS)

SYNOPSIS

       #include <pthread.h>

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

DESCRIPTION

       The pthread_mutexattr_getprioceiling() and  pthread_mutexattr_setprioceiling()  functions,
       respectively,  shall  get  and  set  the  priority ceiling attribute of a mutex attributes
       object  pointed  to   by   attr   which   was   previously   created   by   the   function
       pthread_mutexattr_init().

       The prioceiling attribute contains the priority ceiling of initialized mutexes. The values
       of prioceiling are within the maximum range of priorities defined by SCHED_FIFO.

       The prioceiling attribute defines the priority ceiling of initialized  mutexes,  which  is
       the minimum priority level at which the critical section guarded by the mutex is executed.
       In order to avoid priority inversion, the priority ceiling of the mutex shall be set to  a
       priority  higher  than  or  equal to the highest priority of all the threads that may lock
       that mutex. The values of prioceiling are within the maximum range of  priorities  defined
       under the SCHED_FIFO scheduling policy.

RETURN VALUE

       Upon     successful     completion,     the     pthread_mutexattr_getprioceiling()     and
       pthread_mutexattr_setprioceiling() functions shall return zero; otherwise, an error number
       shall be returned to indicate the error.

ERRORS

       The  pthread_mutexattr_getprioceiling()  and  pthread_mutexattr_setprioceiling() functions
       may fail if:

       EINVAL The value specified by attr or prioceiling is invalid.

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

       These functions shall not return an error code of [EINTR].

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_cond_destroy() , pthread_create() , pthread_mutex_destroy() , the Base Definitions
       volume of IEEE Std 1003.1-2001, <pthread.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2003 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by
       the Institute of Electrical and Electronics Engineers, Inc and  The  Open  Group.  In  the
       event  of  any  discrepancy  between this version and the original IEEE and The Open Group
       Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .