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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/****************************************************************************
**
** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QPROMISE_H
#define QPROMISE_H
#include <QtCore/qglobal.h>
#include <QtCore/qfuture.h>
#include <utility>
QT_REQUIRE_CONFIG(future);
QT_BEGIN_NAMESPACE
template<typename T>
class QPromise
{
static_assert (std::is_move_constructible_v<T>
|| std::is_same_v<T, void>,
"A move-constructible type or type void is required");
public:
QPromise() = default;
Q_DISABLE_COPY(QPromise)
QPromise(QPromise<T> &&other) = default;
QPromise(const QFutureInterface<T> &other) : d(other) {}
QPromise(QFutureInterface<T> &&other) noexcept : d(std::move(other)) {}
QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QPromise)
~QPromise()
{
const int state = d.loadState();
// If QFutureInterface has no state, there is nothing to be done
if (state == static_cast<int>(QFutureInterfaceBase::State::NoState)) {
d.cleanContinuation();
return;
}
// Otherwise, if computation is not finished at this point, cancel
// potential waits
if (!(state & QFutureInterfaceBase::State::Finished)) {
d.cancelAndFinish(); // cancel and finalize the state
d.cleanContinuation();
}
}
// Core QPromise APIs
QFuture<T> future() const { return d.future(); }
template<typename U, typename = QtPrivate::EnableIfSameOrConvertible<U, T>>
bool addResult(U &&result, int index = -1)
{
return d.reportResult(std::forward<U>(result), index);
}
#ifndef QT_NO_EXCEPTIONS
void setException(const QException &e) { d.reportException(e); }
#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0)
void setException(std::exception_ptr e) { d.reportException(e); }
#else
void setException(const std::exception_ptr &e) { d.reportException(e); }
#endif
#endif
void start() { d.reportStarted(); }
void finish() { d.reportFinished(); }
void suspendIfRequested() { d.suspendIfRequested(); }
bool isCanceled() const { return d.isCanceled(); }
// Progress methods
void setProgressRange(int minimum, int maximum) { d.setProgressRange(minimum, maximum); }
void setProgressValue(int progressValue) { d.setProgressValue(progressValue); }
void setProgressValueAndText(int progressValue, const QString &progressText)
{
d.setProgressValueAndText(progressValue, progressText);
}
void swap(QPromise<T> &other) noexcept
{
d.swap(other.d);
}
#if defined(Q_CLANG_QDOC) // documentation-only simplified signatures
bool addResult(const T &result, int index = -1) { }
bool addResult(T &&result, int index = -1) { }
#endif
private:
mutable QFutureInterface<T> d;
};
template<typename T>
inline void swap(QPromise<T> &a, QPromise<T> &b) noexcept
{
a.swap(b);
}
QT_END_NAMESPACE
#endif // QPROMISE_H
|
