1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef QSEMAPHORE_H
#define QSEMAPHORE_H
#include <QtCore/qglobal.h>
#include <QtCore/qmutex.h> // for convertToMilliseconds()
#include <chrono>
QT_REQUIRE_CONFIG(thread);
QT_BEGIN_NAMESPACE
class QSemaphorePrivate;
class Q_CORE_EXPORT QSemaphore
{
public:
explicit QSemaphore(int n = 0);
~QSemaphore();
void acquire(int n = 1);
bool tryAcquire(int n = 1);
bool tryAcquire(int n, int timeout);
template <typename Rep, typename Period>
bool tryAcquire(int n, std::chrono::duration<Rep, Period> timeout)
{ return tryAcquire(n, QtPrivate::convertToMilliseconds(timeout)); }
void release(int n = 1);
int available() const;
// std::counting_semaphore compatibility:
bool try_acquire() noexcept { return tryAcquire(); }
template <typename Rep, typename Period>
bool try_acquire_for(const std::chrono::duration<Rep, Period> &timeout)
{ return tryAcquire(1, timeout); }
template <typename Clock, typename Duration>
bool try_acquire_until(const std::chrono::time_point<Clock, Duration> &tp)
{
return try_acquire_for(tp - Clock::now());
}
private:
Q_DISABLE_COPY(QSemaphore)
union {
QSemaphorePrivate *d;
QBasicAtomicInteger<quintptr> u;
QBasicAtomicInteger<quint32> u32[2];
QBasicAtomicInteger<quint64> u64;
};
};
class QSemaphoreReleaser
{
public:
QSemaphoreReleaser() = default;
explicit QSemaphoreReleaser(QSemaphore &sem, int n = 1) noexcept
: m_sem(&sem), m_n(n) {}
explicit QSemaphoreReleaser(QSemaphore *sem, int n = 1) noexcept
: m_sem(sem), m_n(n) {}
QSemaphoreReleaser(QSemaphoreReleaser &&other) noexcept
: m_sem(other.cancel()), m_n(other.m_n) {}
QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QSemaphoreReleaser)
~QSemaphoreReleaser()
{
if (m_sem)
m_sem->release(m_n);
}
void swap(QSemaphoreReleaser &other) noexcept
{
qt_ptr_swap(m_sem, other.m_sem);
std::swap(m_n, other.m_n);
}
QSemaphore *semaphore() const noexcept
{ return m_sem; }
QSemaphore *cancel() noexcept
{
return qExchange(m_sem, nullptr);
}
private:
QSemaphore *m_sem = nullptr;
int m_n;
};
QT_END_NAMESPACE
#endif // QSEMAPHORE_H
|
