PTHREAD_MUTEX_GETPRIOCEILINGP(O3S)IX Programmer's MaPnTuHaRlEAD_MUTEX_GETPRIOCEILING(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       pthread_mutex_getprioceiling, pthread_mutex_setprioceiling -- get and
       set the priority ceiling of a mutex (REALTIME THREADS)

SYNOPSIS
       #include <pthread.h>

       int pthread_mutex_getprioceiling(const pthread_mutex_t *restrict mutex,
           int *restrict prioceiling);
       int pthread_mutex_setprioceiling(pthread_mutex_t *restrict mutex,
           int prioceiling, int *restrict old__ceiling);

DESCRIPTION
       The pthread__mutex__getprioceiling() function shall return the current
       priority ceiling of the mutex.

       The pthread__mutex__setprioceiling() function shall attempt to lock the
       mutex as if by a call to pthread__mutex__lock(), except that the process
       of locking the mutex need not adhere to the priority protect protocol.
       On acquiring the mutex it shall change the mutex's priority ceiling and
       then release the mutex as if by a call to pthread__mutex__unlock().  When
       the change is successful, the previous value of the priority ceiling
       shall be returned in old__ceiling.

       If the pthread__mutex__setprioceiling() function fails, the mutex
       priority ceiling shall not be changed.

RETURN VALUE
       If successful, the pthread__mutex__getprioceiling() and
       pthread__mutex__setprioceiling() functions shall return zero; otherwise,
       an error number shall be returned to indicate the error.

ERRORS
       These functions shall fail if:

       EINVAL The protocol attribute of mutex is PTHREAD_PRIO_NONE.

       EPERM  The implementation requires appropriate privileges to perform
              the operation and the caller does not have appropriate
              privileges.

       The pthread__mutex__setprioceiling() function shall fail if:

       EAGAIN The mutex could not be acquired because the maximum number of
              recursive locks for mutex has been exceeded.

       EDEADLK
              The mutex type is PTHREAD_MUTEX_ERRORCHECK and the current
              thread already owns the mutex.

       EINVAL The mutex was created with the protocol attribute having the
              value PTHREAD_PRIO_PROTECT and the calling thread's priority is
              higher than the mutex's current priority ceiling, and the
              implementation adheres to the priority protect protocol in the
              process of locking the mutex.

       ENOTRECOVERABLE
              The mutex is a robust mutex and the state protected by the mutex
              is not recoverable.

       EOWNERDEAD
              The mutex is a robust mutex and the process containing the
              previous owning thread terminated while holding the mutex lock.
              The mutex lock shall be acquired by the calling thread and it is
              up to the new owner to make the state consistent (see
              pthread__mutex__lock()).

       The pthread__mutex__setprioceiling() function may fail if:

       EDEADLK
              A deadlock condition was detected.

       EINVAL The priority requested by prioceiling is out of range.

       EOWNERDEAD
              The mutex is a robust mutex and the previous owning thread
              terminated while holding the mutex lock. The mutex lock shall be
              acquired by the calling thread and it is up to the new owner to
              make the state consistent (see pthread__mutex__lock()).

       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__mutex__destroy(), pthread__mutex__lock(),
       pthread__mutex__timedlock()

       The Base Definitions volume of POSIX.1-2017, <pthread.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017      PTHREAD_MUTEX_GETPRIOCEILING(3)
