PTHREAD_MUTEXATTR_GETPRIOCEPOSIX(ProgrammerPTHREAD_MUTEXATTR_GETPRIOCEILING(P)



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_setprio-
       ceiling() functions, respectively, shall get and set the priority ceil-
       ing 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 pri-
       orities defined by SCHED_FIFO.

       The prioceiling attribute defines the priority ceiling  of  initialized
       mutexes, which is the minimum priority level at which the critical sec-
       tion 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; other-
       wise, an error number shall be returned to indicate the error.

ERRORS
       The pthread_mutexattr_getprioceiling()  and  pthread_mutexattr_setprio-
       ceiling() 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)