Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / kern / kern_threads.c
CommitLineData
984263bc
MD
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 */
70int
71thr_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
116int
117thr_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 */
141int
142yield(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