PTHREAD_MUTEX_GETPRIOCEILING
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
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 .