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 .

IEEE/The Open Group                                   2003                   PTHREAD_MUTEXATTR_GETPRIOCEILING(P)