xref: /freebsd/lib/libthr/thread/thr_resume_np.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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_ref_add(curthread, thread, /*include dead*/0)) == 0) {
54 		/* Lock the threads scheduling queue: */
55 		THR_THREAD_LOCK(curthread, thread);
56 		resume_common(thread);
57 		THR_THREAD_UNLOCK(curthread, thread);
58 		_thr_ref_delete(curthread, thread);
59 	}
60 	return (ret);
61 }
62 
63 void
64 _pthread_resume_all_np(void)
65 {
66 	struct pthread *curthread = _get_curthread();
67 	struct pthread *thread;
68 
69 	/* Take the thread list lock: */
70 	THREAD_LIST_LOCK(curthread);
71 
72 	TAILQ_FOREACH(thread, &_thread_list, tle) {
73 		if (thread != curthread) {
74 			THR_THREAD_LOCK(curthread, thread);
75 			resume_common(thread);
76 			THR_THREAD_UNLOCK(curthread, thread);
77 		}
78 	}
79 
80 	/* Release the thread list lock: */
81 	THREAD_LIST_UNLOCK(curthread);
82 }
83 
84 static void
85 resume_common(struct pthread *thread)
86 {
87 	/* Clear the suspend flag: */
88 	thread->flags &= ~THR_FLAGS_NEED_SUSPEND;
89 	thread->cycle++;
90 	_thr_umtx_wake(&thread->cycle, 1);
91 }
92