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.
The pthread_setschedprio() function shall set the scheduling priority
for the thread whose thread ID is given by thread to the value given
by prio. See Scheduling Policies for a description on how this
function call affects the ordering of the thread in the thread list
for its new priority.
If the pthread_setschedprio() function fails, the scheduling priority
of the target thread shall not be changed.
The pthread_setschedprio() function may fail if:
EINVAL The value of prio is invalid for the scheduling policy of the
EPERM The caller does not have appropriate privileges to set the
scheduling priority of the specified thread.
The pthread_setschedprio() function shall not return an error code of
The following sections are informative.
The pthread_setschedprio() function provides a way for an application
to temporarily raise its priority and then lower it again, without
having the undesired side-effect of yielding to other threads of the
same priority. This is necessary if the application is to implement
its own strategies for bounding priority inversion, such as priority
inheritance or priority ceilings. This capability is especially
important if the implementation does not support the Thread Priority
Protection or Thread Priority Inheritance options, but even if those
options are supported it is needed if the application is to bound
priority inheritance for other resources, such as semaphores.
The standard developers considered that while it might be preferable
conceptually to solve this problem by modifying the specification of
pthread_setschedparam(), it was too late to make such a change, as
there may be implementations that would need to be changed.
Therefore, this new function was introduced.
If an implementation detects use of a thread ID after the end of its
lifetime, it is recommended that the function should fail and report
an [ESRCH] error.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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
IEEE/The Open Group 2013 PTHREAD_SETSCHEDPRIO(3P)