1 /* 2 * 3 * Portions of this code was derived from the file kern_fork.c and as such 4 * is subject to the copyrights below. 5 * 6 * Copyright (c) 1982, 1986, 1989, 1991, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * Copyright (c) 1996 Douglas Santry 43 * 44 * This code is subject to the beer copyright. If I chance to meet you in a 45 * bar and this code helped you in some way, you owe me a beer. Only 46 * in Germany will I accept domestic beer. This code may or may not work 47 * and I certainly make no claims as to its fitness for *any* purpose. 48 * 49 * $FreeBSD: src/sys/kern/kern_threads.c,v 1.15 1999/08/28 00:46:15 peter Exp $ 50 */ 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/kernel.h> 55 #include <sys/proc.h> 56 #include <sys/resourcevar.h> 57 #include <sys/sysproto.h> 58 59 /* 60 * Low level support for sleep/wakeup paradigm 61 * If a timeout is specified: 62 * returns 0 if wakeup 63 * returns EAGAIN if timed out 64 * returns EINVAL if error 65 * 66 * If a timeout is not specified: 67 * 68 * returns time waiting in ticks. 69 */ 70 int 71 thr_sleep(struct proc *p, struct thr_sleep_args *uap) { 72 int sleepstart; 73 struct timespec ts; 74 struct timeval atv; 75 int error, timo; 76 77 timo = 0; 78 if (uap->timeout != 0) { 79 /* 80 * Get timespec struct 81 */ 82 if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0) { 83 p->p_wakeup = 0; 84 return error; 85 } 86 if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000) { 87 p->p_wakeup = 0; 88 return (EINVAL); 89 } 90 TIMESPEC_TO_TIMEVAL(&atv, &ts); 91 if (itimerfix(&atv)) { 92 p->p_wakeup = 0; 93 return (EINVAL); 94 } 95 timo = tvtohz(&atv); 96 } 97 98 p->p_retval[0] = 0; 99 if (p->p_wakeup == 0) { 100 sleepstart = ticks; 101 p->p_flag |= P_SINTR; 102 error = tsleep(p, PRIBIO, "thrslp", timo); 103 p->p_flag &= ~P_SINTR; 104 if (error == EWOULDBLOCK) { 105 p->p_wakeup = 0; 106 p->p_retval[0] = EAGAIN; 107 return 0; 108 } 109 if (uap->timeout == 0) 110 p->p_retval[0] = ticks - sleepstart; 111 } 112 p->p_wakeup = 0; 113 return (0); 114 } 115 116 int 117 thr_wakeup(struct proc *p, struct thr_wakeup_args *uap) { 118 struct proc *pSlave = p->p_leader; 119 120 while(pSlave && (pSlave->p_pid != uap->pid)) 121 pSlave = pSlave->p_peers; 122 123 if(pSlave == 0) { 124 p->p_retval[0] = ESRCH; 125 return(0); 126 } 127 128 pSlave->p_wakeup++; 129 if((pSlave->p_stat == SSLEEP) && (pSlave->p_wchan == pSlave)) { 130 wakeup(pSlave); 131 return(0); 132 } 133 134 p->p_retval[0] = EAGAIN; 135 return 0; 136 } 137 138 /* 139 * General purpose yield system call 140 */ 141 int 142 yield(struct proc *p, struct yield_args *uap) { 143 int s; 144 145 p->p_retval[0] = 0; 146 147 s = splhigh(); 148 p->p_priority = MAXPRI; 149 setrunqueue(p); 150 p->p_stats->p_ru.ru_nvcsw++; 151 mi_switch(); 152 splx(s); 153 154 return(0); 155 } 156 157