xref: /freebsd/lib/libthr/thread/thr_resume_np.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the author nor the names of any co-contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "namespace.h"
36 #include <errno.h>
37 #include <pthread.h>
38 #include <pthread_np.h>
39 #include "un-namespace.h"
40 
41 #include "thr_private.h"
42 
43 __weak_reference(_pthread_resume_np, pthread_resume_np);
44 __weak_reference(_pthread_resume_all_np, pthread_resume_all_np);
45 
46 static void resume_common(struct pthread *thread);
47 
48 /* Resume a thread: */
49 int
50 _pthread_resume_np(pthread_t thread)
51 {
52 	struct pthread *curthread = _get_curthread();
53 	int ret;
54 
55 	/* Add a reference to the thread: */
56 	if ((ret = _thr_find_thread(curthread, thread, /*include dead*/0)) == 0) {
57 		/* Lock the threads scheduling queue: */
58 		resume_common(thread);
59 		THR_THREAD_UNLOCK(curthread, thread);
60 	}
61 	return (ret);
62 }
63 
64 void
65 _pthread_resume_all_np(void)
66 {
67 	struct pthread *curthread = _get_curthread();
68 	struct pthread *thread;
69 	int old_nocancel;
70 
71 	old_nocancel = curthread->no_cancel;
72 	curthread->no_cancel = 1;
73 	_thr_suspend_all_lock(curthread);
74 	/* Take the thread list lock: */
75 	THREAD_LIST_RDLOCK(curthread);
76 
77 	TAILQ_FOREACH(thread, &_thread_list, tle) {
78 		if (thread != curthread) {
79 			THR_THREAD_LOCK(curthread, thread);
80 			resume_common(thread);
81 			THR_THREAD_UNLOCK(curthread, thread);
82 		}
83 	}
84 
85 	/* Release the thread list lock: */
86 	THREAD_LIST_UNLOCK(curthread);
87 	_thr_suspend_all_unlock(curthread);
88 	curthread->no_cancel = old_nocancel;
89 	_thr_testcancel(curthread);
90 }
91 
92 static void
93 resume_common(struct pthread *thread)
94 {
95 	/* Clear the suspend flag: */
96 	thread->flags &= ~(THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED);
97 	thread->cycle++;
98 	_thr_umtx_wake(&thread->cycle, 1, 0);
99 }
100