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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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 are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <Kernel/Thread.h>
28#include <Kernel/WaitQueue.h>
29
30namespace Kernel {
31
32WaitQueue::WaitQueue()
33{
34}
35
36WaitQueue::~WaitQueue()
37{
38}
39
40void WaitQueue::enqueue(Thread& thread)
41{
42 InterruptDisabler disabler;
43 m_threads.append(thread);
44}
45
46void WaitQueue::wake_one(Atomic<bool>* lock)
47{
48 InterruptDisabler disabler;
49 if (lock)
50 *lock = false;
51 if (m_threads.is_empty())
52 return;
53 if (auto* thread = m_threads.take_first())
54 thread->wake_from_queue();
55 Scheduler::stop_idling();
56}
57
58void WaitQueue::wake_all()
59{
60 InterruptDisabler disabler;
61 if (m_threads.is_empty())
62 return;
63 while (!m_threads.is_empty())
64 m_threads.take_first()->wake_from_queue();
65 Scheduler::stop_idling();
66}
67
68void WaitQueue::clear()
69{
70 InterruptDisabler disabler;
71 m_threads.clear();
72}
73
74}