thr_kern.c revision 331722 
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
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/11/lib/libthr/thread/thr_kern.c 331722 2018-03-29 02:50:57Z eadler $");
30
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
46static struct umutex	addr_lock;
47static struct wake_addr *wake_addr_head;
48static 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 */
54int
55_thr_setthreaded(int threaded)
56{
57	if (((threaded == 0) ^ (__isthreaded == 0)) == 0)
58		return (0);
59
60	__isthreaded = threaded;
61	return (0);
62}
63
64void
65_thr_assert_lock_level(void)
66{
67	PANIC("locklevel <= 0");
68}
69
70int
71_rtp_to_schedparam(const struct rtprio *rtp, int *policy,
72	struct sched_param *param)
73{
74	switch(rtp->type) {
75	case RTP_PRIO_REALTIME:
76		*policy = SCHED_RR;
77		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
78		break;
79	case RTP_PRIO_FIFO:
80		*policy = SCHED_FIFO;
81		param->sched_priority = RTP_PRIO_MAX - rtp->prio;
82		break;
83	default:
84		*policy = SCHED_OTHER;
85		param->sched_priority = 0;
86		break;
87	}
88	return (0);
89}
90
91int
92_schedparam_to_rtp(int policy, const struct sched_param *param,
93	struct rtprio *rtp)
94{
95	switch(policy) {
96	case SCHED_RR:
97		rtp->type = RTP_PRIO_REALTIME;
98		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
99		break;
100	case SCHED_FIFO:
101		rtp->type = RTP_PRIO_FIFO;
102		rtp->prio = RTP_PRIO_MAX - param->sched_priority;
103		break;
104	case SCHED_OTHER:
105	default:
106		rtp->type = RTP_PRIO_NORMAL;
107		rtp->prio = 0;
108		break;
109	}
110	return (0);
111}
112
113int
114_thr_getscheduler(lwpid_t lwpid, int *policy, struct sched_param *param)
115{
116	struct rtprio rtp;
117	int ret;
118
119	ret = rtprio_thread(RTP_LOOKUP, lwpid, &rtp);
120	if (ret == -1)
121		return (ret);
122	_rtp_to_schedparam(&rtp, policy, param);
123	return (0);
124}
125
126int
127_thr_setscheduler(lwpid_t lwpid, int policy, const struct sched_param *param)
128{
129	struct rtprio rtp;
130
131	_schedparam_to_rtp(policy, param, &rtp);
132	return (rtprio_thread(RTP_SET, lwpid, &rtp));
133}
134
135void
136_thr_wake_addr_init(void)
137{
138	_thr_umutex_init(&addr_lock);
139	wake_addr_head = NULL;
140}
141
142/*
143 * Allocate wake-address, the memory area is never freed after
144 * allocated, this becauses threads may be referencing it.
145 */
146struct wake_addr *
147_thr_alloc_wake_addr(void)
148{
149	struct pthread *curthread;
150	struct wake_addr *p;
151
152	if (_thr_initial == NULL) {
153		return &default_wake_addr;
154	}
155
156	curthread = _get_curthread();
157
158	THR_LOCK_ACQUIRE(curthread, &addr_lock);
159	if (wake_addr_head == NULL) {
160		unsigned i;
161		unsigned pagesize = getpagesize();
162		struct wake_addr *pp = (struct wake_addr *)
163			mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE,
164			MAP_ANON|MAP_PRIVATE, -1, 0);
165		for (i = 1; i < pagesize/sizeof(struct wake_addr); ++i)
166			pp[i].link = &pp[i+1];
167		pp[i-1].link = NULL;
168		wake_addr_head = &pp[1];
169		p = &pp[0];
170	} else {
171		p = wake_addr_head;
172		wake_addr_head = p->link;
173	}
174	THR_LOCK_RELEASE(curthread, &addr_lock);
175	p->value = 0;
176	return (p);
177}
178
179void
180_thr_release_wake_addr(struct wake_addr *wa)
181{
182	struct pthread *curthread = _get_curthread();
183
184	if (wa == &default_wake_addr)
185		return;
186	THR_LOCK_ACQUIRE(curthread, &addr_lock);
187	wa->link = wake_addr_head;
188	wake_addr_head = wa;
189	THR_LOCK_RELEASE(curthread, &addr_lock);
190}
191
192/* Sleep on thread wakeup address */
193int
194_thr_sleep(struct pthread *curthread, int clockid,
195	const struct timespec *abstime)
196{
197
198	if (curthread->wake_addr->value != 0)
199		return (0);
200
201	return _thr_umtx_timedwait_uint(&curthread->wake_addr->value, 0,
202                 clockid, abstime, 0);
203}
204
205void
206_thr_wake_all(unsigned int *waddrs[], int count)
207{
208	int i;
209
210	for (i = 0; i < count; ++i)
211		*waddrs[i] = 1;
212	_umtx_op(waddrs, UMTX_OP_NWAKE_PRIVATE, count, NULL, NULL);
213}
214