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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 appropriately.
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_setscheduler(2) for a description of Linux scheduling
Programming for the real world − POSIX.4 by Bill O. Gallmeister, O'Reilly & Associates, Inc., ISBN 1-56592-074-0.
This page is part of release 3.52 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man−pages/.
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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 |