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41
42#ifndef QMUTEX_H
43#define QMUTEX_H
44
45#include <QtCore/qglobal.h>
46#include <QtCore/qatomic.h>
47#include <new>
48
49QT_BEGIN_HEADER
50
51QT_BEGIN_NAMESPACE
52
53QT_MODULE(Core)
54
55#ifndef QT_NO_THREAD
56
57class QAtomicInt;
58class QMutexData;
59
60class Q_CORE_EXPORT QMutex
61{
62 friend class QWaitCondition;
63 friend class QWaitConditionPrivate;
64
65public:
66 enum RecursionMode { NonRecursive, Recursive };
67
68 explicit QMutex(RecursionMode mode = NonRecursive);
69 ~QMutex();
70
71 void lock(); //### Qt5: make inline;
72 inline void lockInline();
73 bool tryLock(); //### Qt5: make inline;
74 bool tryLock(int timeout);
75 inline bool tryLockInline();
76 void unlock(); //### Qt5: make inline;
77 inline void unlockInline();
78
79#if defined(QT3_SUPPORT)
80 inline QT3_SUPPORT bool locked()
81 {
82 if (!tryLock())
83 return true;
84 unlock();
85 return false;
86 }
87 inline QT3_SUPPORT_CONSTRUCTOR QMutex(bool recursive)
88 {
89 new (this) QMutex(recursive ? Recursive : NonRecursive);
90 }
91#endif
92
93private:
94 void lockInternal();
95 void unlockInternal();
96 Q_DISABLE_COPY(QMutex)
97
98 QMutexData *d;
99};
100
101class Q_CORE_EXPORT QMutexLocker
102{
103public:
104 inline explicit QMutexLocker(QMutex *m)
105 {
106 Q_ASSERT_X((reinterpret_cast<quintptr>(m) & quintptr(1u)) == quintptr(0),
107 "QMutexLocker", "QMutex pointer is misaligned");
108 if (m) {
109 m->lockInline();
110 val = reinterpret_cast<quintptr>(m) | quintptr(1u);
111 } else {
112 val = 0;
113 }
114 }
115 inline ~QMutexLocker() { unlock(); }
116
117 inline void unlock()
118 {
119 if ((val & quintptr(1u)) == quintptr(1u)) {
120 val &= ~quintptr(1u);
121 mutex()->unlockInline();
122 }
123 }
124
125 inline void relock()
126 {
127 if (val) {
128 if ((val & quintptr(1u)) == quintptr(0u)) {
129 mutex()->lockInline();
130 val |= quintptr(1u);
131 }
132 }
133 }
134
135#if defined(Q_CC_MSVC)
136#pragma warning( push )
137#pragma warning( disable : 4312 ) // ignoring the warning from /Wp64
138#endif
139
140 inline QMutex *mutex() const
141 {
142 return reinterpret_cast<QMutex *>(val & ~quintptr(1u));
143 }
144
145#if defined(Q_CC_MSVC)
146#pragma warning( pop )
147#endif
148
149private:
150 Q_DISABLE_COPY(QMutexLocker)
151
152 quintptr val;
153};
154
155class QMutexData
156{
157 public:
158 QAtomicInt contenders;
159 const uint recursive : 1;
160 uint reserved : 31;
161 protected:
162 QMutexData(QMutex::RecursionMode mode);
163 ~QMutexData();
164};
165
166#ifdef QT_NO_DEBUG
167inline void QMutex::unlockInline()
168{
169 if (d->recursive) {
170 unlock();
171 } else if (!d->contenders.testAndSetRelease(1, 0)) {
172 unlockInternal();
173 }
174}
175
176inline bool QMutex::tryLockInline()
177{
178 if (d->recursive) {
179 return tryLock();
180 } else {
181 return d->contenders.testAndSetAcquire(0, 1);
182 }
183}
184
185inline void QMutex::lockInline()
186{
187 if (d->recursive) {
188 lock();
189 } else if(!tryLockInline()) {
190 lockInternal();
191 }
192}
193#else // QT_NO_DEBUG
194//in debug we do not use inline calls in order to allow debugging tools
195// to hook the mutex locking functions.
196inline void QMutex::unlockInline() { unlock(); }
197inline bool QMutex::tryLockInline() { return tryLock(); }
198inline void QMutex::lockInline() { lock(); }
199#endif // QT_NO_DEBUG
200
201
202#else // QT_NO_THREAD
203
204
205class Q_CORE_EXPORT QMutex
206{
207public:
208 enum RecursionMode { NonRecursive, Recursive };
209
210 inline explicit QMutex(RecursionMode mode = NonRecursive) { Q_UNUSED(mode); }
211 inline ~QMutex() {}
212
213 static inline void lock() {}
214 static inline void lockInline() {}
215 static inline bool tryLock(int timeout = 0) { Q_UNUSED(timeout); return true; }
216 static inline bool tryLockInline() { return true; }
217 static inline void unlock() {}
218 static inline void unlockInline() {}
219
220#if defined(QT3_SUPPORT)
221 static inline QT3_SUPPORT bool locked() { return false; }
222#endif
223
224private:
225 Q_DISABLE_COPY(QMutex)
226};
227
228class Q_CORE_EXPORT QMutexLocker
229{
230public:
231 inline explicit QMutexLocker(QMutex *) {}
232 inline ~QMutexLocker() {}
233
234 static inline void unlock() {}
235 static void relock() {}
236 static inline QMutex *mutex() { return 0; }
237
238private:
239 Q_DISABLE_COPY(QMutexLocker)
240};
241
242#endif // QT_NO_THREAD
243
244QT_END_NAMESPACE
245
246QT_END_HEADER
247
248#endif // QMUTEX_H
249