Qt 6.x
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qreadwritelock.h
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1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QREADWRITELOCK_H
5#define QREADWRITELOCK_H
6
7#include <QtCore/qglobal.h>
8#include <QtCore/qdeadlinetimer.h>
9
10QT_BEGIN_NAMESPACE
11
12#if QT_CONFIG(thread)
13
14class QReadWriteLockPrivate;
15
16class Q_CORE_EXPORT QReadWriteLock
17{
18public:
19 enum RecursionMode { NonRecursive, Recursive };
20
21 QT_CORE_INLINE_SINCE(6, 6)
22 explicit QReadWriteLock(RecursionMode recursionMode = NonRecursive);
23 QT_CORE_INLINE_SINCE(6, 6)
24 ~QReadWriteLock();
25
26 QT_CORE_INLINE_SINCE(6, 6)
27 void lockForRead();
28#if QT_CORE_REMOVED_SINCE(6, 6)
29 bool tryLockForRead();
30#endif
31 QT_CORE_INLINE_SINCE(6, 6)
32 bool tryLockForRead(int timeout);
33 bool tryLockForRead(QDeadlineTimer timeout = {});
34
35 QT_CORE_INLINE_SINCE(6, 6)
36 void lockForWrite();
37#if QT_CORE_REMOVED_SINCE(6, 6)
38 bool tryLockForWrite();
39#endif
40 QT_CORE_INLINE_SINCE(6, 6)
41 bool tryLockForWrite(int timeout);
42 bool tryLockForWrite(QDeadlineTimer timeout = {});
43
44 void unlock();
45
46private:
47 Q_DISABLE_COPY(QReadWriteLock)
48 QAtomicPointer<QReadWriteLockPrivate> d_ptr;
49 friend class QReadWriteLockPrivate;
50 static QReadWriteLockPrivate *initRecursive();
51 static void destroyRecursive(QReadWriteLockPrivate *);
52};
53
54#if QT_CORE_INLINE_IMPL_SINCE(6, 6)
55QReadWriteLock::QReadWriteLock(RecursionMode recursionMode)
56 : d_ptr(recursionMode == Recursive ? initRecursive() : nullptr)
57{
58}
59
60QReadWriteLock::~QReadWriteLock()
61{
62 if (auto d = d_ptr.loadAcquire())
63 destroyRecursive(d);
64}
65
66void QReadWriteLock::lockForRead()
67{
68 tryLockForRead(QDeadlineTimer(QDeadlineTimer::Forever));
69}
70
71bool QReadWriteLock::tryLockForRead(int timeout)
72{
73 return tryLockForRead(QDeadlineTimer(timeout));
74}
75
76void QReadWriteLock::lockForWrite()
77{
78 tryLockForWrite(QDeadlineTimer(QDeadlineTimer::Forever));
79}
80
81bool QReadWriteLock::tryLockForWrite(int timeout)
82{
83 return tryLockForWrite(QDeadlineTimer(timeout));
84}
85#endif // inline since 6.6
86
87#if defined(Q_CC_MSVC)
88#pragma warning( push )
89#pragma warning( disable : 4312 ) // ignoring the warning from /Wp64
90#endif
91
92class QT6_ONLY(Q_CORE_EXPORT) QReadLocker
93{
94public:
95 Q_NODISCARD_CTOR
96 inline QReadLocker(QReadWriteLock *readWriteLock);
97
98 inline ~QReadLocker()
99 { unlock(); }
100
101 inline void unlock()
102 {
103 if (q_val) {
104 if ((q_val & quintptr(1u)) == quintptr(1u)) {
105 q_val &= ~quintptr(1u);
106 readWriteLock()->unlock();
107 }
108 }
109 }
110
111 inline void relock()
112 {
113 if (q_val) {
114 if ((q_val & quintptr(1u)) == quintptr(0u)) {
115 readWriteLock()->lockForRead();
116 q_val |= quintptr(1u);
117 }
118 }
119 }
120
121 inline QReadWriteLock *readWriteLock() const
122 { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }
123
124private:
125 Q_DISABLE_COPY(QReadLocker)
126 quintptr q_val;
127};
128
129inline QReadLocker::QReadLocker(QReadWriteLock *areadWriteLock)
130 : q_val(reinterpret_cast<quintptr>(areadWriteLock))
131{
132 Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),
133 "QReadLocker", "QReadWriteLock pointer is misaligned");
134 relock();
135}
136
137class QT6_ONLY(Q_CORE_EXPORT) QWriteLocker
138{
139public:
140 Q_NODISCARD_CTOR
141 inline QWriteLocker(QReadWriteLock *readWriteLock);
142
143 inline ~QWriteLocker()
144 { unlock(); }
145
146 inline void unlock()
147 {
148 if (q_val) {
149 if ((q_val & quintptr(1u)) == quintptr(1u)) {
150 q_val &= ~quintptr(1u);
151 readWriteLock()->unlock();
152 }
153 }
154 }
155
156 inline void relock()
157 {
158 if (q_val) {
159 if ((q_val & quintptr(1u)) == quintptr(0u)) {
160 readWriteLock()->lockForWrite();
161 q_val |= quintptr(1u);
162 }
163 }
164 }
165
166 inline QReadWriteLock *readWriteLock() const
167 { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }
168
169
170private:
171 Q_DISABLE_COPY(QWriteLocker)
172 quintptr q_val;
173};
174
175inline QWriteLocker::QWriteLocker(QReadWriteLock *areadWriteLock)
176 : q_val(reinterpret_cast<quintptr>(areadWriteLock))
177{
178 Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),
179 "QWriteLocker", "QReadWriteLock pointer is misaligned");
180 relock();
181}
182
183#if defined(Q_CC_MSVC)
184#pragma warning( pop )
185#endif
186
187#else // QT_CONFIG(thread)
188
189class QT6_ONLY(Q_CORE_EXPORT) QReadWriteLock
190{
191public:
192 enum RecursionMode { NonRecursive, Recursive };
193 inline explicit QReadWriteLock(RecursionMode = NonRecursive) noexcept { }
194 inline ~QReadWriteLock() { }
195
196 void lockForRead() noexcept { }
197 bool tryLockForRead() noexcept { return true; }
198 bool tryLockForRead(QDeadlineTimer) noexcept { return true; }
199 bool tryLockForRead(int timeout) noexcept { Q_UNUSED(timeout); return true; }
200
201 void lockForWrite() noexcept { }
202 bool tryLockForWrite() noexcept { return true; }
203 bool tryLockForWrite(QDeadlineTimer) noexcept { return true; }
204 bool tryLockForWrite(int timeout) noexcept { Q_UNUSED(timeout); return true; }
205
206 void unlock() noexcept { }
207
208private:
209 Q_DISABLE_COPY(QReadWriteLock)
210};
211
212class QT6_ONLY(Q_CORE_EXPORT) QReadLocker
213{
214public:
215 Q_NODISCARD_CTOR
216 inline explicit QReadLocker(QReadWriteLock *) noexcept { }
217 inline ~QReadLocker() noexcept { }
218
219 void unlock() noexcept { }
220 void relock() noexcept { }
221 QReadWriteLock *readWriteLock() noexcept { return nullptr; }
222
223private:
224 Q_DISABLE_COPY(QReadLocker)
225};
226
227class QT6_ONLY(Q_CORE_EXPORT) QWriteLocker
228{
229public:
230 Q_NODISCARD_CTOR
231 inline explicit QWriteLocker(QReadWriteLock *) noexcept { }
232 inline ~QWriteLocker() noexcept { }
233
234 void unlock() noexcept { }
235 void relock() noexcept { }
236 QReadWriteLock *readWriteLock() noexcept { return nullptr; }
237
238private:
239 Q_DISABLE_COPY(QWriteLocker)
240};
241
242#endif // QT_CONFIG(thread)
243
244QT_END_NAMESPACE
245
246#endif // QREADWRITELOCK_H
QAtomicPointer
\macro Q_ATOMIC_INTnn_IS_SUPPORTED
Definition qatomic.h:123
QDeadlineTimer
\inmodule QtCore
Definition qdeadlinetimer.h:24
QDeadlineTimer::Forever
static constexpr ForeverConstant Forever
Definition qdeadlinetimer.h:27
QReadLocker
\inmodule QtCore
QReadWriteLock
\inmodule QtCore
QWriteLocker
\inmodule QtCore
QT_BEGIN_NAMESPACE
Combined button and popup list for selecting options.
Definition qstandardpaths_haiku.cpp:21
QT_END_NAMESPACE
Definition qsharedpointer.cpp:1545
Q_NODISCARD_CTOR
#define Q_NODISCARD_CTOR
Definition qcompilerdetection.h:1024
void
DBusConnection const char DBusError DBusBusType DBusError return DBusConnection DBusHandleMessageFunction void DBusFreeFunction return DBusConnection return DBusConnection return const char DBusError return DBusConnection DBusMessage dbus_uint32_t return DBusConnection dbus_bool_t DBusConnection DBusAddWatchFunction DBusRemoveWatchFunction DBusWatchToggledFunction void DBusFreeFunction return DBusConnection DBusDispatchStatusFunction void DBusFreeFunction DBusTimeout return DBusTimeout return DBusWatch return DBusWatch unsigned int return DBusError const DBusError return const DBusMessage return DBusMessage return DBusMessage return DBusMessage return DBusMessage return DBusMessage return DBusMessageIter int const void return DBusMessageIter DBusMessageIter return DBusMessageIter void DBusMessageIter void int return DBusMessage DBusMessageIter return DBusMessageIter return DBusMessageIter DBusMessageIter const char const char const char const char return DBusMessage return DBusMessage const char return DBusMessage dbus_bool_t return DBusMessage dbus_uint32_t return DBusMessage void
Definition qdbus_symbols_p.h:401
timeout
GLbitfield GLuint64 timeout
[4]
Definition qopengles2ext.h:1029
Q_ASSERT_X
#define Q_ASSERT_X(cond, x, msg)
Definition qrandom.cpp:48
Q_UNUSED
#define Q_UNUSED(x)
Definition qtpreprocessorsupport.h:20
quintptr
size_t quintptr
Definition qtypes.h:72
explicit
#define explicit
Definition qxcbconnection.cpp:33
nullptr
QObject::connect nullptr
Definition src_corelib_kernel_qobject.cpp:255
d
double d
Definition src_corelib_text_qlocale.cpp:9
unlock
mutex unlock()