thr_resume_np.c revision 330897 
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: stable/11/lib/libthr/thread/thr_resume_np.c 330897 2018-03-14 03:19:51Z eadler $");
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
46static void resume_common(struct pthread *thread);
47
48/* Resume a thread: */
49int
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
64void
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
92static void
93resume_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