yield.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1996-2002 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/thread.h>
#include <sys/disp.h>
#include <sys/debug.h>
#include <sys/cpuvar.h>
/*
* The calling LWP is preempted in favor of some other LWP.
*/
int
yield()
{
kthread_t *t = curthread;
klwp_t *lwp = ttolwp(t);
thread_lock(t);
lwp->lwp_ru.nvcsw++;
THREAD_TRANSITION(t);
CL_YIELD(t); /* does setbackdq */
thread_unlock_nopreempt(t);
swtch(); /* clears cpu_runrun and cpu_kprunrun */
return (0);
}