PTHREAD_MUTEXATTR_GETPRIOCEIPLOISNIGX(3P)rogrammer'PsTHMRaEnAuDa_lMUTEXATTR_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_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.

       The behavior is undefined if the value specified by the attr argument
       to pthread__mutexattr__getprioceiling() or
       pthread__mutexattr__setprioceiling() does not refer to an initialized
       mutex attributes object.

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
       These functions may fail if:

       EINVAL The value specified by 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
       If an implementation detects that the value specified by the attr
       argument to pthread__mutexattr__getprioceiling() or
       pthread__mutexattr__setprioceiling() does not refer to an initialized
       mutex attributes object, it is recommended that the function should
       fail and report an [EINVAL] error.

FUTURE DIRECTIONS
       None.

SEE ALSO
       pthread__cond__destroy(), pthread__create(), pthread__mutex__destroy()

       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_MUTEXATTR_GETPRIOCEILING(3)
