xref: /dflybsd-src/sys/kern/kern_threads.c (revision 90ea502b8c5d21f908cedff6680ee2bc9e74ce74)
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 
171