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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 <AK/Function.h>
28#include <AK/NonnullOwnPtr.h>
29#include <AK/OwnPtr.h>
30#include <Kernel/Scheduler.h>
31#include <Kernel/TimerQueue.h>
32
33namespace Kernel {
34
35static TimerQueue* s_the;
36
37TimerQueue& TimerQueue::the()
38{
39 if (!s_the)
40 s_the = new TimerQueue;
41 return *s_the;
42}
43
44u64 TimerQueue::add_timer(NonnullOwnPtr<Timer>&& timer)
45{
46 ASSERT(timer->expires > g_uptime);
47
48 timer->id = ++m_timer_id_count;
49
50 auto following_timer = m_timer_queue.find([&timer](auto& other) { return other->expires > timer->expires; });
51 if (following_timer.is_end())
52 m_timer_queue.append(move(timer));
53 else
54 m_timer_queue.insert_before(following_timer, move(timer));
55
56 update_next_timer_due();
57
58 return m_timer_id_count;
59}
60
61u64 TimerQueue::add_timer(u64 duration, TimeUnit unit, Function<void()>&& callback)
62{
63 NonnullOwnPtr timer = make<Timer>();
64 timer->expires = g_uptime + duration * unit;
65 timer->callback = move(callback);
66 return add_timer(move(timer));
67}
68
69bool TimerQueue::cancel_timer(u64 id)
70{
71 auto it = m_timer_queue.find([id](auto& timer) { return timer->id == id; });
72 if (it.is_end())
73 return false;
74 m_timer_queue.remove(it);
75 update_next_timer_due();
76 return true;
77}
78
79void TimerQueue::fire()
80{
81 if (m_timer_queue.is_empty())
82 return;
83
84 ASSERT(m_next_timer_due == m_timer_queue.first()->expires);
85
86 while (!m_timer_queue.is_empty() && g_uptime > m_timer_queue.first()->expires) {
87 auto timer = m_timer_queue.take_first();
88 timer->callback();
89 }
90
91 update_next_timer_due();
92}
93
94void TimerQueue::update_next_timer_due()
95{
96 if (m_timer_queue.is_empty())
97 m_next_timer_due = 0;
98 else
99 m_next_timer_due = m_timer_queue.first()->expires;
100}
101
102}