1/*
2 * Copyright (C) 2010-2016 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/Condition.h>
29#include <wtf/Lock.h>
30#include <wtf/Noncopyable.h>
31#include <wtf/TimeWithDynamicClockType.h>
32
33namespace WTF {
34
35class BinarySemaphore final {
36 WTF_MAKE_NONCOPYABLE(BinarySemaphore);
37 WTF_MAKE_FAST_ALLOCATED;
38public:
39 constexpr BinarySemaphore() = default;
40
41 WTF_EXPORT_PRIVATE void signal();
42 WTF_EXPORT_PRIVATE bool waitUntil(const TimeWithDynamicClockType&);
43
44 bool waitFor(Seconds relativeTimeout)
45 {
46 return waitUntil(MonotonicTime::now() + relativeTimeout);
47 }
48
49 void wait()
50 {
51 waitUntil(ParkingLot::Time::infinity());
52 }
53
54private:
55 bool m_isSet { false };
56 Lock m_lock;
57 Condition m_condition;
58};
59
60} // namespace WTF
61
62using WTF::BinarySemaphore;
63