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 * $FreeBSD$
30 */
31
32 #include "namespace.h"
33 #include <errno.h>
34 #include <pthread.h>
35 #include "un-namespace.h"
36 #include "thr_private.h"
37
38 int _pthread_suspend_np(pthread_t thread);
39 void _pthread_suspend_all_np(void);
40
41 static void suspend_common(struct pthread *thread);
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: */
47 int
_pthread_suspend_np(pthread_t thread)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_SCHED_LOCK(curthread, thread);
62 suspend_common(thread);
63 /* Unlock the threads scheduling queue: */
64 THR_SCHED_UNLOCK(curthread, thread);
65
66 /* Don't forget to remove the reference: */
67 _thr_ref_delete(curthread, thread);
68 }
69 return (ret);
70 }
71
72 void
_pthread_suspend_all_np(void)73 _pthread_suspend_all_np(void)
74 {
75 struct pthread *curthread = _get_curthread();
76 struct pthread *thread;
77 kse_critical_t crit;
78
79 /* Take the thread list lock: */
80 crit = _kse_critical_enter();
81 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
82
83 TAILQ_FOREACH(thread, &_thread_list, tle) {
84 if (thread != curthread) {
85 THR_SCHED_LOCK(curthread, thread);
86 suspend_common(thread);
87 THR_SCHED_UNLOCK(curthread, thread);
88 }
89 }
90
91 /* Release the thread list lock: */
92 KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
93 _kse_critical_leave(crit);
94 }
95
96 void
suspend_common(struct pthread * thread)97 suspend_common(struct pthread *thread)
98 {
99 if ((thread->state != PS_DEAD) &&
100 (thread->state != PS_DEADLOCK) &&
101 ((thread->flags & THR_FLAGS_EXITING) == 0)) {
102 thread->flags |= THR_FLAGS_SUSPENDED;
103 if ((thread->flags & THR_FLAGS_IN_RUNQ) != 0) {
104 THR_RUNQ_REMOVE(thread);
105 THR_SET_STATE(thread, PS_SUSPENDED);
106 }
107 #ifdef NOT_YET
108 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0)
109 /* ??? */
110 #endif
111 }
112 }
113