xref: /freebsd/lib/libthr/thread/thr_kern.c (revision 50dad48bb740a8e56d185d9e8c165e0758f46e25)
1 /*
2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3  * Copyright (C) 2003 Daniel M. Eischen <deischen@freebsd.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice unmodified, this list of conditions, and the following
11  *    disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/types.h>
31 #include <sys/signalvar.h>
32 #include <sys/rtprio.h>
33 #include <sys/mman.h>
34 #include <pthread.h>
35 
36 #include "thr_private.h"
37 
38 /*#define DEBUG_THREAD_KERN */
39 #ifdef DEBUG_THREAD_KERN
40 #define DBG_MSG		stdout_debug
41 #else
42 #define DBG_MSG(x...)
43 #endif
44 
45 static struct umutex	addr_lock;
46 static struct wake_addr *wake_addr_head;
47 static struct wake_addr default_wake_addr;
48 
49 /*
50  * This is called when the first thread (other than the initial
51  * thread) is created.
52  */
53 int
54 _thr_setthreaded(int threaded)
55 {
56 	if (((threaded == 0) ^ (__isthreaded == 0)) == 0)
57 		return (0);
58 
59 	__isthreaded = threaded;
60 	if (threaded != 0) {
61 		_thr_rtld_init();
62 	} else {
63 		_thr_rtld_fini();
64 	}
65 	return (0);
66 }
67 
68 void
69 _thr_assert_lock_level()
70 {
71 	PANIC("locklevel <= 0");
72 }
73 
74 int
75 _rtp_to_schedparam(const struct rtprio *rtp, int *policy,
76 	struct sched_param *param)
77 {
78 	switch(rtp->type) {
79 	case RTP_PRIO_REALTIME:
80 		*policy = SCHED_RR;
81 		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
82 		break;
83 	case RTP_PRIO_FIFO:
84 		*policy = SCHED_FIFO;
85 		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
86 		break;
87 	default:
88 		*policy = SCHED_OTHER;
89 		param->sched_priority = 0;
90 		break;
91 	}
92 	return (0);
93 }
94 
95 int
96 _schedparam_to_rtp(int policy, const struct sched_param *param,
97 	struct rtprio *rtp)
98 {
99 	switch(policy) {
100 	case SCHED_RR:
101 		rtp->type = RTP_PRIO_REALTIME;
102 		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
103 		break;
104 	case SCHED_FIFO:
105 		rtp->type = RTP_PRIO_FIFO;
106 		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
107 		break;
108 	case SCHED_OTHER:
109 	default:
110 		rtp->type = RTP_PRIO_NORMAL;
111 		rtp->prio = 0;
112 		break;
113 	}
114 	return (0);
115 }
116 
117 int
118 _thr_getscheduler(lwpid_t lwpid, int *policy, struct sched_param *param)
119 {
120 	struct rtprio rtp;
121 	int ret;
122 
123 	ret = rtprio_thread(RTP_LOOKUP, lwpid, &rtp);
124 	if (ret == -1)
125 		return (ret);
126 	_rtp_to_schedparam(&rtp, policy, param);
127 	return (0);
128 }
129 
130 int
131 _thr_setscheduler(lwpid_t lwpid, int policy, const struct sched_param *param)
132 {
133 	struct rtprio rtp;
134 
135 	_schedparam_to_rtp(policy, param, &rtp);
136 	return (rtprio_thread(RTP_SET, lwpid, &rtp));
137 }
138 
139 void
140 _thr_wake_addr_init(void)
141 {
142 	_thr_umutex_init(&addr_lock);
143 	wake_addr_head = NULL;
144 }
145 
146 /*
147  * Allocate wake-address, the memory area is never freed after
148  * allocated, this becauses threads may be referencing it.
149  */
150 struct wake_addr *
151 _thr_alloc_wake_addr(void)
152 {
153 	struct pthread *curthread;
154 	struct wake_addr *p;
155 
156 	if (_thr_initial == NULL) {
157 		return &default_wake_addr;
158 	}
159 
160 	curthread = _get_curthread();
161 
162 	THR_LOCK_ACQUIRE(curthread, &addr_lock);
163 	if (wake_addr_head == NULL) {
164 		unsigned i;
165 		unsigned pagesize = getpagesize();
166 		struct wake_addr *pp = (struct wake_addr *)
167 			mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE,
168 			MAP_ANON|MAP_PRIVATE, -1, 0);
169 		for (i = 1; i < pagesize/sizeof(struct wake_addr); ++i)
170 			pp[i].link = &pp[i+1];
171 		pp[i-1].link = NULL;
172 		wake_addr_head = &pp[1];
173 		p = &pp[0];
174 	} else {
175 		p = wake_addr_head;
176 		wake_addr_head = p->link;
177 	}
178 	THR_LOCK_RELEASE(curthread, &addr_lock);
179 	p->value = 0;
180 	return (p);
181 }
182 
183 void
184 _thr_release_wake_addr(struct wake_addr *wa)
185 {
186 	struct pthread *curthread = _get_curthread();
187 
188 	if (wa == &default_wake_addr)
189 		return;
190 	THR_LOCK_ACQUIRE(curthread, &addr_lock);
191 	wa->link = wake_addr_head;
192 	wake_addr_head = wa;
193 	THR_LOCK_RELEASE(curthread, &addr_lock);
194 }
195 
196 /* Sleep on thread wakeup address */
197 int
198 _thr_sleep(struct pthread *curthread, int clockid,
199 	const struct timespec *abstime)
200 {
201 
202 	curthread->will_sleep = 0;
203 	if (curthread->nwaiter_defer > 0) {
204 		_thr_wake_all(curthread->defer_waiters,
205 			curthread->nwaiter_defer);
206 		curthread->nwaiter_defer = 0;
207 	}
208 
209 	if (curthread->wake_addr->value != 0)
210 		return (0);
211 
212 	return _thr_umtx_timedwait_uint(&curthread->wake_addr->value, 0,
213                  clockid, abstime, 0);
214 }
215 
216 void
217 _thr_wake_all(unsigned int *waddrs[], int count)
218 {
219 	int i;
220 
221 	for (i = 0; i < count; ++i)
222 		*waddrs[i] = 1;
223 	_umtx_op(waddrs, UMTX_OP_NWAKE_PRIVATE, count, NULL, NULL);
224 }
225