1/* 2 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: releng/10.2/lib/libkse/thread/thr_yield.c 174689 2007-12-16 23:29:57Z deischen $ 30 */ 31#include <pthread.h> 32#include "thr_private.h" 33 34int _sched_yield(void); 35 36__weak_reference(_sched_yield, sched_yield); 37__weak_reference(_pthread_yield, pthread_yield); 38 39int 40_sched_yield(void) 41{ 42 struct pthread *curthread = _get_curthread(); 43 44 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) 45 return (__sys_sched_yield()); 46 47 /* Reset the accumulated time slice value for the current thread: */ 48 curthread->slice_usec = -1; 49 50 /* Schedule the next thread: */ 51 _thr_sched_switch(curthread); 52 /* Always return no error. */ 53 return(0); 54} 55 56/* Draft 4 yield */ 57void 58_pthread_yield(void) 59{ 60 struct pthread *curthread = _get_curthread(); 61 62 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) { 63 __sys_sched_yield(); 64 return; 65 } 66 67 /* Reset the accumulated time slice value for the current thread: */ 68 curthread->slice_usec = -1; 69 70 /* Schedule the next thread: */ 71 _thr_sched_switch(curthread); 72} 73