sched_yield — yield the processor
#include <sched.h>
int
sched_yield( |
void); |
sched_yield() causes the
calling thread to relinquish the CPU. The thread is moved to
the end of the queue for its static priority and a new thread
gets to run.
On success, sched_yield()
returns 0. On error, −1 is returned, and errno is set to indicate the error.
If the calling thread is the only thread in the highest
priority list at that time, it will continue to run after a
call to sched_yield().
POSIX systems on which sched_yield() is available define
_POSIX_PRIORITY_SCHEDULING in
<unistd.h>
Strategic calls to sched_yield() can improve performance by
giving other threads or processes a chance to run when
(heavily) contended resources (e.g., mutexes) have been
released by the caller. Avoid calling sched_yield() unnecessarily or
inappropriately (e.g., when resources needed by other
schedulable threads are still held by the caller), since
doing so will result in unnecessary context switches, which
will degrade system performance.
sched_yield() is intended
for use with real-time scheduling policies (i.e.,
SCHED_FIFO or SCHED_RR). Use of sched_yield() with nondeterministic
scheduling policies such as SCHED_OTHER is unspecified and very likely
means your application design is broken.
This page is part of release 5.11 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright (C) Tom Bjorkholm & Markus Kuhn, 1996 %%%LICENSE_START(GPLv2+_DOC_FULL) This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or typesetting system, including intermediate and printed output. This manual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this manual; if not, see <http://www.gnu.org/licenses/>. %%%LICENSE_END 1996-04-01 Tom Bjorkholm <tombmydata.se> First version written 1996-04-10 Markus Kuhn <mskuhncip.informatik.uni-erlangen.de> revision |