1/*
2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
|
29 * $FreeBSD: head/lib/libthr/thread/thr_suspend_np.c 178647 2008-04-29 03:58:18Z davidxu $
|
| 29 * $FreeBSD: head/lib/libthr/thread/thr_suspend_np.c 212536 2010-09-13 07:03:01Z davidxu $ |
30 */
31
32#include "namespace.h"
33#include <errno.h>
34#include <pthread.h>
35#include <pthread_np.h>
36#include "un-namespace.h"
37
38#include "thr_private.h"
39
40static int suspend_common(struct pthread *, struct pthread *,
41 int);
42
43__weak_reference(_pthread_suspend_np, pthread_suspend_np);
44__weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np);
45
46/* Suspend a thread: */
47int
48_pthread_suspend_np(pthread_t thread)
49{
50 struct pthread *curthread = _get_curthread();
51 int ret;
52
53 /* Suspending the current thread doesn't make sense. */
54 if (thread == _get_curthread())
55 ret = EDEADLK;
56
57 /* Add a reference to the thread: */
58 else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0))
59 == 0) {
60 /* Lock the threads scheduling queue: */
61 THR_THREAD_LOCK(curthread, thread);
62 suspend_common(curthread, thread, 1);
63 /* Unlock the threads scheduling queue: */
64 THR_THREAD_UNLOCK(curthread, thread);
65
66 /* Don't forget to remove the reference: */
67 _thr_ref_delete(curthread, thread);
68 }
69 return (ret);
70}
71
72void
73_pthread_suspend_all_np(void)
74{
75 struct pthread *curthread = _get_curthread();
76 struct pthread *thread;
77 int ret;
78
|
79 THREAD_LIST_LOCK(curthread);
|
| 79 THREAD_LIST_RDLOCK(curthread); |
80
81 TAILQ_FOREACH(thread, &_thread_list, tle) {
82 if (thread != curthread) {
83 THR_THREAD_LOCK(curthread, thread);
84 if (thread->state != PS_DEAD &&
85 !(thread->flags & THR_FLAGS_SUSPENDED))
86 thread->flags |= THR_FLAGS_NEED_SUSPEND;
87 THR_THREAD_UNLOCK(curthread, thread);
88 }
89 }
90 thr_kill(-1, SIGCANCEL);
91
92restart:
93 TAILQ_FOREACH(thread, &_thread_list, tle) {
94 if (thread != curthread) {
95 /* First try to suspend the thread without waiting */
96 THR_THREAD_LOCK(curthread, thread);
97 ret = suspend_common(curthread, thread, 0);
98 if (ret == 0) {
|
99 /* Can not suspend, try to wait */
100 thread->refcount++;
|
99 THREAD_LIST_UNLOCK(curthread);
|
100 /* Can not suspend, try to wait */
101 THR_REF_ADD(curthread, thread); |
102 suspend_common(curthread, thread, 1);
|
103 THR_THREAD_UNLOCK(curthread, thread);
104 THREAD_LIST_LOCK(curthread);
105 _thr_ref_delete_unlocked(curthread, thread);
|
103 THR_REF_DEL(curthread, thread);
104 _thr_try_gc(curthread, thread);
105 /* thread lock released */
106
107 THREAD_LIST_RDLOCK(curthread); |
108 /*
109 * Because we were blocked, things may have
110 * been changed, we have to restart the
111 * process.
112 */
113 goto restart;
114 }
115 THR_THREAD_UNLOCK(curthread, thread);
116 }
117 }
118
119 THREAD_LIST_UNLOCK(curthread);
120}
121
122static int
123suspend_common(struct pthread *curthread, struct pthread *thread,
124 int waitok)
125{
126 long tmp;
127
128 while (thread->state != PS_DEAD &&
129 !(thread->flags & THR_FLAGS_SUSPENDED)) {
130 thread->flags |= THR_FLAGS_NEED_SUSPEND;
131 tmp = thread->cycle;
|
130 THR_THREAD_UNLOCK(curthread, thread);
|
132 _thr_send_sig(thread, SIGCANCEL);
|
| 133 THR_THREAD_UNLOCK(curthread, thread); |
134 if (waitok) {
135 _thr_umtx_wait_uint(&thread->cycle, tmp, NULL, 0);
136 THR_THREAD_LOCK(curthread, thread);
137 } else {
138 THR_THREAD_LOCK(curthread, thread);
139 return (0);
140 }
141 }
142
143 return (1);
144}
|