pthread_setschedprio(3p) — Linux manual page

PTHREAD_...CHEDPRIO(3P) POSIX Programmer's ManualPTHREAD_...CHEDPRIO(3P)

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_setschedprio — dynamic thread scheduling parameters
       access (REALTIME THREADS)

SYNOPSIS

       #include <pthread.h>

       int pthread_setschedprio(pthread_t thread, int prio);

DESCRIPTION

       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.

RETURN VALUE

       If successful, the pthread_setschedprio() function shall return
       zero; otherwise, an error number shall be returned to indicate
       the error.

ERRORS

       The pthread_setschedprio() function may fail if:

       EINVAL The value of prio is invalid for the scheduling policy of
              the specified thread.

       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 [EINTR].

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       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.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Scheduling Policies, pthread_getschedparam(3p)

       The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)

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_...CHEDPRIO(3P)

Pages that refer to this page: pthread.h(0p), pthread_getschedparam(3p)

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