1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1996-2002 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 #include <sys/param.h> 31 #include <sys/types.h> 32 #include <sys/sysmacros.h> 33 #include <sys/systm.h> 34 #include <sys/errno.h> 35 #include <sys/thread.h> 36 #include <sys/disp.h> 37 #include <sys/debug.h> 38 #include <sys/cpuvar.h> 39 40 41 /* 42 * The calling LWP is preempted in favor of some other LWP. 43 */ 44 int 45 yield() 46 { 47 kthread_t *t = curthread; 48 klwp_t *lwp = ttolwp(t); 49 50 thread_lock(t); 51 lwp->lwp_ru.nvcsw++; 52 THREAD_TRANSITION(t); 53 CL_YIELD(t); /* does setbackdq */ 54 thread_unlock_nopreempt(t); 55 swtch(); /* clears cpu_runrun and cpu_kprunrun */ 56 57 return (0); 58 } 59