Make thread suspension really work.
[dragonfly.git] / lib / libthread_xu / thread / thr_resume_np.c
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1/*
2 * Copyright (c) 1995 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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: src/lib/libpthread/thread/thr_resume_np.c,v 1.18 2003/07/23 02:11:07 deischen Exp $
fd4288bd 33 * $DragonFly: src/lib/libthread_xu/thread/thr_resume_np.c,v 1.3 2006/03/19 13:07:12 davidxu Exp $
71b3fa15 34 */
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35
36#include <machine/tls.h>
37
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38#include <errno.h>
39#include <pthread.h>
40#include "thr_private.h"
41
42__weak_reference(_pthread_resume_np, pthread_resume_np);
43__weak_reference(_pthread_resume_all_np, pthread_resume_all_np);
44
45static void resume_common(struct pthread *thread);
46
47/* Resume a thread: */
48int
49_pthread_resume_np(pthread_t thread)
50{
9e2ee207 51 struct pthread *curthread = tls_get_curthread();
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52 int ret;
53
54 /* Add a reference to the thread: */
55 if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0)) == 0) {
56 /* Lock the threads scheduling queue: */
57 THR_THREAD_LOCK(curthread, thread);
58 resume_common(thread);
59 THR_THREAD_UNLOCK(curthread, thread);
60 _thr_ref_delete(curthread, thread);
61 }
62 return (ret);
63}
64
65void
66_pthread_resume_all_np(void)
67{
9e2ee207 68 struct pthread *curthread = tls_get_curthread();
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69 struct pthread *thread;
70
71 /* Take the thread list lock: */
72 THREAD_LIST_LOCK(curthread);
73
74 TAILQ_FOREACH(thread, &_thread_list, tle) {
75 if (thread != curthread) {
76 THR_THREAD_LOCK(curthread, thread);
77 resume_common(thread);
78 THR_THREAD_UNLOCK(curthread, thread);
79 }
80 }
81
82 /* Release the thread list lock: */
83 THREAD_LIST_UNLOCK(curthread);
84}
85
86static void
87resume_common(struct pthread *thread)
88{
89 /* Clear the suspend flag: */
90 thread->flags &= ~THR_FLAGS_NEED_SUSPEND;
91 thread->cycle++;
92 _thr_umtx_wake(&thread->cycle, 1);
71b3fa15 93}