thr_suspend_np.c revision 165967 
1/*
2 * Copyright (c) 1995-1998 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: head/lib/libkse/thread/thr_suspend_np.c 165967 2007-01-12 07:26:21Z imp $
30 */
31#include <errno.h>
32#include <pthread.h>
33#include "thr_private.h"
34
35static void suspend_common(struct pthread *thread);
36
37LT10_COMPAT_PRIVATE(_pthread_suspend_np);
38LT10_COMPAT_DEFAULT(pthread_suspend_np);
39LT10_COMPAT_PRIVATE(_pthread_suspend_all_np);
40LT10_COMPAT_DEFAULT(pthread_suspend_all_np);
41
42__weak_reference(_pthread_suspend_np, pthread_suspend_np);
43__weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np);
44
45/* Suspend a thread: */
46int
47_pthread_suspend_np(pthread_t thread)
48{
49	struct pthread *curthread = _get_curthread();
50	int ret;
51
52	/* Suspending the current thread doesn't make sense. */
53	if (thread == _get_curthread())
54		ret = EDEADLK;
55
56	/* Add a reference to the thread: */
57	else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0))
58	    == 0) {
59		/* Lock the threads scheduling queue: */
60		THR_SCHED_LOCK(curthread, thread);
61		suspend_common(thread);
62		/* Unlock the threads scheduling queue: */
63		THR_SCHED_UNLOCK(curthread, thread);
64
65		/* Don't forget to remove the reference: */
66		_thr_ref_delete(curthread, thread);
67	}
68	return (ret);
69}
70
71void
72_pthread_suspend_all_np(void)
73{
74	struct pthread	*curthread = _get_curthread();
75	struct pthread	*thread;
76	kse_critical_t crit;
77
78	/* Take the thread list lock: */
79	crit = _kse_critical_enter();
80	KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
81
82	TAILQ_FOREACH(thread, &_thread_list, tle) {
83		if (thread != curthread) {
84			THR_SCHED_LOCK(curthread, thread);
85			suspend_common(thread);
86			THR_SCHED_UNLOCK(curthread, thread);
87		}
88	}
89
90	/* Release the thread list lock: */
91	KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
92	_kse_critical_leave(crit);
93}
94
95void
96suspend_common(struct pthread *thread)
97{
98	if ((thread->state != PS_DEAD) &&
99	    (thread->state != PS_DEADLOCK) &&
100	    ((thread->flags & THR_FLAGS_EXITING) == 0)) {
101		thread->flags |= THR_FLAGS_SUSPENDED;
102		if ((thread->flags & THR_FLAGS_IN_RUNQ) != 0) {
103			THR_RUNQ_REMOVE(thread);
104			THR_SET_STATE(thread, PS_SUSPENDED);
105		}
106#ifdef NOT_YET
107		if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0)
108			/* ??? */
109#endif
110	}
111}
112