xref: /freebsd/lib/libthr/thread/thr_kern.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
5  * Copyright (C) 2003 Daniel M. Eischen <deischen@freebsd.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include <sys/types.h>
32 #include <sys/signalvar.h>
33 #include <sys/rtprio.h>
34 #include <sys/mman.h>
35 #include <pthread.h>
36 
37 #include "thr_private.h"
38 
39 /*#define DEBUG_THREAD_KERN */
40 #ifdef DEBUG_THREAD_KERN
41 #define DBG_MSG		stdout_debug
42 #else
43 #define DBG_MSG(x...)
44 #endif
45 
46 static struct umutex	addr_lock;
47 static struct wake_addr *wake_addr_head;
48 static struct wake_addr default_wake_addr;
49 
50 /*
51  * This is called when the first thread (other than the initial
52  * thread) is created.
53  */
54 void
55 _thr_setthreaded(int threaded)
56 {
57 	__isthreaded = threaded;
58 }
59 
60 void
61 _thr_assert_lock_level(void)
62 {
63 	PANIC("locklevel <= 0");
64 }
65 
66 int
67 _rtp_to_schedparam(const struct rtprio *rtp, int *policy,
68 	struct sched_param *param)
69 {
70 	switch(rtp->type) {
71 	case RTP_PRIO_REALTIME:
72 		*policy = SCHED_RR;
73 		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
74 		break;
75 	case RTP_PRIO_FIFO:
76 		*policy = SCHED_FIFO;
77 		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
78 		break;
79 	default:
80 		*policy = SCHED_OTHER;
81 		param->sched_priority = 0;
82 		break;
83 	}
84 	return (0);
85 }
86 
87 int
88 _schedparam_to_rtp(int policy, const struct sched_param *param,
89 	struct rtprio *rtp)
90 {
91 	switch(policy) {
92 	case SCHED_RR:
93 		rtp->type = RTP_PRIO_REALTIME;
94 		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
95 		break;
96 	case SCHED_FIFO:
97 		rtp->type = RTP_PRIO_FIFO;
98 		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
99 		break;
100 	case SCHED_OTHER:
101 	default:
102 		rtp->type = RTP_PRIO_NORMAL;
103 		rtp->prio = 0;
104 		break;
105 	}
106 	return (0);
107 }
108 
109 int
110 _thr_getscheduler(lwpid_t lwpid, int *policy, struct sched_param *param)
111 {
112 	struct rtprio rtp;
113 	int ret;
114 
115 	ret = rtprio_thread(RTP_LOOKUP, lwpid, &rtp);
116 	if (ret == -1)
117 		return (ret);
118 	_rtp_to_schedparam(&rtp, policy, param);
119 	return (0);
120 }
121 
122 int
123 _thr_setscheduler(lwpid_t lwpid, int policy, const struct sched_param *param)
124 {
125 	struct rtprio rtp;
126 
127 	_schedparam_to_rtp(policy, param, &rtp);
128 	return (rtprio_thread(RTP_SET, lwpid, &rtp));
129 }
130 
131 void
132 _thr_wake_addr_init(void)
133 {
134 	_thr_umutex_init(&addr_lock);
135 	wake_addr_head = NULL;
136 }
137 
138 /*
139  * Allocate wake-address, the memory area is never freed after
140  * allocated, this becauses threads may be referencing it.
141  */
142 struct wake_addr *
143 _thr_alloc_wake_addr(void)
144 {
145 	struct pthread *curthread;
146 	struct wake_addr *p;
147 
148 	if (_thr_initial == NULL) {
149 		return &default_wake_addr;
150 	}
151 
152 	curthread = _get_curthread();
153 
154 	THR_LOCK_ACQUIRE(curthread, &addr_lock);
155 	if (wake_addr_head == NULL) {
156 		unsigned i;
157 		unsigned pagesize = getpagesize();
158 		struct wake_addr *pp = (struct wake_addr *)
159 			mmap(NULL, pagesize, PROT_READ|PROT_WRITE,
160 			MAP_ANON|MAP_PRIVATE, -1, 0);
161 		for (i = 1; i < pagesize/sizeof(struct wake_addr); ++i)
162 			pp[i].link = &pp[i+1];
163 		pp[i-1].link = NULL;
164 		wake_addr_head = &pp[1];
165 		p = &pp[0];
166 	} else {
167 		p = wake_addr_head;
168 		wake_addr_head = p->link;
169 	}
170 	THR_LOCK_RELEASE(curthread, &addr_lock);
171 	p->value = 0;
172 	return (p);
173 }
174 
175 void
176 _thr_release_wake_addr(struct wake_addr *wa)
177 {
178 	struct pthread *curthread = _get_curthread();
179 
180 	if (wa == &default_wake_addr)
181 		return;
182 	THR_LOCK_ACQUIRE(curthread, &addr_lock);
183 	wa->link = wake_addr_head;
184 	wake_addr_head = wa;
185 	THR_LOCK_RELEASE(curthread, &addr_lock);
186 }
187 
188 /* Sleep on thread wakeup address */
189 int
190 _thr_sleep(struct pthread *curthread, int clockid,
191 	const struct timespec *abstime)
192 {
193 
194 	if (curthread->wake_addr->value != 0)
195 		return (0);
196 
197 	return _thr_umtx_timedwait_uint(&curthread->wake_addr->value, 0,
198                  clockid, abstime, 0);
199 }
200 
201 void
202 _thr_wake_all(unsigned int *waddrs[], int count)
203 {
204 	int i;
205 
206 	for (i = 0; i < count; ++i)
207 		*waddrs[i] = 1;
208 	_umtx_op(waddrs, UMTX_OP_NWAKE_PRIVATE, count, NULL, NULL);
209 }
210