sys/kern/kern_threads.c

   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. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * Copyright (c) 1996 Douglas Santry
  39  *
  40  * This code is subject to the beer copyright.  If I chance to meet you in a
  41  * bar and this code helped you in some way, you owe me a beer.  Only
  42  * in Germany will I accept domestic beer.  This code may or may not work
  43  * and I certainly make no claims as to its fitness for *any* purpose.
  44  *
  45  * $FreeBSD: src/sys/kern/kern_threads.c,v 1.15 1999/08/28 00:46:15 peter Exp $
  46  * $DragonFly: src/sys/kern/kern_threads.c,v 1.12 2007/02/18 16:12:43 corecode Exp $
  47  */
  48
  49 #include <sys/param.h>
  50 #include <sys/systm.h>
  51 #include <sys/kernel.h>
  52 #include <sys/proc.h>
  53 #include <sys/resourcevar.h>
  54 #include <sys/sysproto.h>
  55
  56 #if 0
  57
  58 /*
  59  * XXX lwp
  60  *
  61  * I am unhappy code, please remove me
  62  */
  63
  64
  65 /*
  66  * Low level support for sleep/wakeup paradigm
  67  * If a timeout is specified:
  68  *      returns 0 if wakeup
  69  *      returns EAGAIN if timed out
  70  *      returns EINVAL if error
  71  *
  72  * If a timeout is not specified:
  73  *
  74  *      returns time waiting in ticks.
  75  */
  76 int
  77 sys_thr_sleep(struct thr_sleep_args *uap)
  78 {
  79         struct proc *p = curproc;
  80         struct lwp *lp = curthread->td_lwp;
  81         int sleepstart;
  82         struct timespec ts;
  83         struct timeval atv;
  84         int error, timo;
  85
  86         timo = 0;
  87         if (uap->timeout != 0) {
  88                 /*
  89                  * Get timespec struct
  90                  */
  91                 if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0) {
  92                         p->p_wakeup = 0;
  93                         return error;
  94                 }
  95                 if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000) {
  96                         p->p_wakeup = 0;
  97                         return (EINVAL);
  98                 }
  99                 TIMESPEC_TO_TIMEVAL(&atv, &ts);
 100                 if (itimerfix(&atv)) {
 101                         p->p_wakeup = 0;
 102                         return (EINVAL);
 103                 }
 104                 timo = tvtohz_high(&atv);
 105         }
 106
 107         uap->sysmsg_result = 0;
 108         if (p->p_wakeup == 0) {
 109                 sleepstart = ticks;
 110                 lp->lwp_flags |= LWP_SINTR;
 111                 error = tsleep(p, 0, "thrslp", timo);
 112                 lp->lwp_flags &= ~LWP_SINTR;
 113                 if (error == EWOULDBLOCK) {
 114                         p->p_wakeup = 0;
 115                         uap->sysmsg_result = EAGAIN;
 116                         return 0;
 117                 }
 118                 if (uap->timeout == 0)
 119                         uap->sysmsg_result = ticks - sleepstart;
 120         }
 121         p->p_wakeup = 0;
 122         return (0);
 123 }
 124
 125 int
 126 sys_thr_wakeup(struct thr_wakeup_args *uap)
 127 {
 128         struct proc *p = curproc;
 129         struct proc *pSlave = p->p_leader;
 130         struct lwp *lpSlave;
 131
 132         while(pSlave && (pSlave->p_pid != uap->pid))
 133                 pSlave = pSlave->p_peers;
 134
 135         if(pSlave == 0) {
 136                 uap->sysmsg_result = ESRCH;
 137                 return(0);
 138         }
 139
 140         lpSlave = FIRST_LWP_IN_PROC(pSlave);
 141         pSlave->p_wakeup++;
 142         if((lpSlave->lwp_stat == LSSLEEP) && lpSlave->lwp_wchan == pSlave) {
 143                 wakeup(pSlave);
 144                 return(0);
 145         }
 146
 147         uap->sysmsg_result = EAGAIN;
 148         return 0;
 149 }
 150
 151 #endif
 152
 153 /*
 154  * General purpose yield system call
 155  *
 156  * MPSAFE
 157  */
 158 int
 159 sys_yield(struct yield_args *uap)
 160 {
 161         uap->sysmsg_result = 0;
 162         lwkt_user_yield();
 163         return(0);
 164 }
 165