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. 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  * $DragonFly: src/sys/kern/kern_threads.c,v 1.12 2007/02/18 16:12:43 corecode Exp $
  51  */
  52
  53 #include <sys/param.h>
  54 #include <sys/systm.h>
  55 #include <sys/kernel.h>
  56 #include <sys/proc.h>
  57 #include <sys/resourcevar.h>
  58 #include <sys/sysproto.h>
  59 #include <sys/uio.h>            /* uio_yield() fixme */
  60
  61 #if 0
  62
  63 /*
  64  * XXX lwp
  65  *
  66  * I am unhappy code, please remove me
  67  */
  68
  69
  70 /*
  71  * Low level support for sleep/wakeup paradigm
  72  * If a timeout is specified:
  73  *      returns 0 if wakeup
  74  *      returns EAGAIN if timed out
  75  *      returns EINVAL if error
  76  *
  77  * If a timeout is not specified:
  78  *
  79  *      returns time waiting in ticks.
  80  */
  81 int
  82 sys_thr_sleep(struct thr_sleep_args *uap)
  83 {
  84         struct proc *p = curproc;
  85         struct lwp *lp = curthread->td_lwp;
  86         int sleepstart;
  87         struct timespec ts;
  88         struct timeval atv;
  89         int error, timo;
  90
  91         timo = 0;
  92         if (uap->timeout != 0) {
  93                 /*
  94                  * Get timespec struct
  95                  */
  96                 if ((error = copyin(uap->timeout, &ts, sizeof(ts))) != 0) {
  97                         p->p_wakeup = 0;
  98                         return error;
  99                 }
 100                 if (ts.tv_nsec < 0 || ts.tv_nsec >= 1000000000) {
 101                         p->p_wakeup = 0;
 102                         return (EINVAL);
 103                 }
 104                 TIMESPEC_TO_TIMEVAL(&atv, &ts);
 105                 if (itimerfix(&atv)) {
 106                         p->p_wakeup = 0;
 107                         return (EINVAL);
 108                 }
 109                 timo = tvtohz_high(&atv);
 110         }
 111
 112         uap->sysmsg_result = 0;
 113         if (p->p_wakeup == 0) {
 114                 sleepstart = ticks;
 115                 lp->lwp_flag |= LWP_SINTR;
 116                 error = tsleep(p, 0, "thrslp", timo);
 117                 lp->lwp_flag &= ~LWP_SINTR;
 118                 if (error == EWOULDBLOCK) {
 119                         p->p_wakeup = 0;
 120                         uap->sysmsg_result = EAGAIN;
 121                         return 0;
 122                 }
 123                 if (uap->timeout == 0)
 124                         uap->sysmsg_result = ticks - sleepstart;
 125         }
 126         p->p_wakeup = 0;
 127         return (0);
 128 }
 129
 130 int
 131 sys_thr_wakeup(struct thr_wakeup_args *uap)
 132 {
 133         struct proc *p = curproc;
 134         struct proc *pSlave = p->p_leader;
 135         struct lwp *lpSlave;
 136
 137         while(pSlave && (pSlave->p_pid != uap->pid))
 138                 pSlave = pSlave->p_peers;
 139
 140         if(pSlave == 0) {
 141                 uap->sysmsg_result = ESRCH;
 142                 return(0);
 143         }
 144
 145         lpSlave = FIRST_LWP_IN_PROC(pSlave);
 146         pSlave->p_wakeup++;
 147         if((lpSlave->lwp_stat == LSSLEEP) && lpSlave->lwp_wchan == pSlave) {
 148                 wakeup(pSlave);
 149                 return(0);
 150         }
 151
 152         uap->sysmsg_result = EAGAIN;
 153         return 0;
 154 }
 155
 156 #endif
 157
 158 /*
 159  * General purpose yield system call
 160  *
 161  * MPSAFE
 162  */
 163 int
 164 sys_yield(struct yield_args *uap)
 165 {
 166         uap->sysmsg_result = 0;
 167         uio_yield();
 168         return(0);
 169 }
 170