xref: /freebsd/lib/libthr/thread/thr_resume_np.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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. 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 <pthread_np.h>
36 #include "un-namespace.h"
37 
38 #include "thr_private.h"
39 
40 __weak_reference(_pthread_resume_np, pthread_resume_np);
41 __weak_reference(_pthread_resume_all_np, pthread_resume_all_np);
42 
43 static void resume_common(struct pthread *thread);
44 
45 /* Resume a thread: */
46 int
47 _pthread_resume_np(pthread_t thread)
48 {
49 	struct pthread *curthread = _get_curthread();
50 	int ret;
51 
52 	/* Add a reference to the thread: */
53 	if ((ret = _thr_find_thread(curthread, thread, /*include dead*/0)) == 0) {
54 		/* Lock the threads scheduling queue: */
55 		resume_common(thread);
56 		THR_THREAD_UNLOCK(curthread, thread);
57 	}
58 	return (ret);
59 }
60 
61 void
62 _pthread_resume_all_np(void)
63 {
64 	struct pthread *curthread = _get_curthread();
65 	struct pthread *thread;
66 	int old_nocancel;
67 
68 	old_nocancel = curthread->no_cancel;
69 	curthread->no_cancel = 1;
70 	_thr_suspend_all_lock(curthread);
71 	/* Take the thread list lock: */
72 	THREAD_LIST_RDLOCK(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 	_thr_suspend_all_unlock(curthread);
85 	curthread->no_cancel = old_nocancel;
86 	_thr_testcancel(curthread);
87 }
88 
89 static void
90 resume_common(struct pthread *thread)
91 {
92 	/* Clear the suspend flag: */
93 	thread->flags &= ~THR_FLAGS_NEED_SUSPEND;
94 	thread->cycle++;
95 	_thr_umtx_wake(&thread->cycle, 1, 0);
96 }
97