Qt 4.8
qreadwritelock.h
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41 
42 #ifndef QREADWRITELOCK_H
43 #define QREADWRITELOCK_H
44 
45 #include <QtCore/qglobal.h>
46 #include <limits.h> // ### Qt 5: remove
47 
49 
51 
52 QT_MODULE(Core)
53 
54 #ifndef QT_NO_THREAD
55 
57 
59 {
60 public:
61  enum RecursionMode { NonRecursive, Recursive };
62 
63  QReadWriteLock(); // ### Qt 5: merge with below
64  QReadWriteLock(RecursionMode recursionMode);
65  ~QReadWriteLock();
66 
67  void lockForRead();
68  bool tryLockForRead();
69  bool tryLockForRead(int timeout);
70 
71  void lockForWrite();
72  bool tryLockForWrite();
73  bool tryLockForWrite(int timeout);
74 
75  void unlock();
76 
77 private:
80 
82 };
83 
84 #if defined(Q_CC_MSVC)
85 #pragma warning( push )
86 #pragma warning( disable : 4312 ) // ignoring the warning from /Wp64
87 #endif
88 
90 {
91 public:
92  inline QReadLocker(QReadWriteLock *readWriteLock);
93 
94  inline ~QReadLocker()
95  { unlock(); }
96 
97  inline void unlock()
98  {
99  if (q_val) {
100  if ((q_val & quintptr(1u)) == quintptr(1u)) {
101  q_val &= ~quintptr(1u);
102  readWriteLock()->unlock();
103  }
104  }
105  }
106 
107  inline void relock()
108  {
109  if (q_val) {
110  if ((q_val & quintptr(1u)) == quintptr(0u)) {
111  readWriteLock()->lockForRead();
112  q_val |= quintptr(1u);
113  }
114  }
115  }
116 
118  { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }
119 
120 private:
122  quintptr q_val;
123 };
124 
125 inline QReadLocker::QReadLocker(QReadWriteLock *areadWriteLock)
126  : q_val(reinterpret_cast<quintptr>(areadWriteLock))
127 {
128  Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),
129  "QReadLocker", "QReadWriteLock pointer is misaligned");
130  relock();
131 }
132 
134 {
135 public:
136  inline QWriteLocker(QReadWriteLock *readWriteLock);
137 
138  inline ~QWriteLocker()
139  { unlock(); }
140 
141  inline void unlock()
142  {
143  if (q_val) {
144  if ((q_val & quintptr(1u)) == quintptr(1u)) {
145  q_val &= ~quintptr(1u);
146  readWriteLock()->unlock();
147  }
148  }
149  }
150 
151  inline void relock()
152  {
153  if (q_val) {
154  if ((q_val & quintptr(1u)) == quintptr(0u)) {
155  readWriteLock()->lockForWrite();
156  q_val |= quintptr(1u);
157  }
158  }
159  }
160 
162  { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }
163 
164 
165 private:
167  quintptr q_val;
168 };
169 
170 inline QWriteLocker::QWriteLocker(QReadWriteLock *areadWriteLock)
171  : q_val(reinterpret_cast<quintptr>(areadWriteLock))
172 {
173  Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),
174  "QWriteLocker", "QReadWriteLock pointer is misaligned");
175  relock();
176 }
177 
178 #if defined(Q_CC_MSVC)
179 #pragma warning( pop )
180 #endif
181 
182 #else // QT_NO_THREAD
183 
184 class Q_CORE_EXPORT QReadWriteLock
185 {
186 public:
187  enum RecursionMode { NonRecursive, Recursive };
188  inline explicit QReadWriteLock(RecursionMode = NonRecursive) { }
189  inline ~QReadWriteLock() { }
190 
191  static inline void lockForRead() { }
192  static inline bool tryLockForRead() { return true; }
193  static inline bool tryLockForRead(int timeout) { Q_UNUSED(timeout); return true; }
194 
195  static inline void lockForWrite() { }
196  static inline bool tryLockForWrite() { return true; }
197  static inline bool tryLockForWrite(int timeout) { Q_UNUSED(timeout); return true; }
198 
199  static inline void unlock() { }
200 
201 private:
202  Q_DISABLE_COPY(QReadWriteLock)
203 };
204 
205 class Q_CORE_EXPORT QReadLocker
206 {
207 public:
208  inline QReadLocker(QReadWriteLock *) { }
209  inline ~QReadLocker() { }
210 
211  static inline void unlock() { }
212  static inline void relock() { }
213  static inline QReadWriteLock *readWriteLock() { return 0; }
214 
215 private:
216  Q_DISABLE_COPY(QReadLocker)
217 };
218 
219 class Q_CORE_EXPORT QWriteLocker
220 {
221 public:
222  inline explicit QWriteLocker(QReadWriteLock *) { }
223  inline ~QWriteLocker() { }
224 
225  static inline void unlock() { }
226  static inline void relock() { }
227  static inline QReadWriteLock *readWriteLock() { return 0; }
228 
229 private:
230  Q_DISABLE_COPY(QWriteLocker)
231 };
232 
233 #endif // QT_NO_THREAD
234 
236 
238 
239 #endif // QREADWRITELOCK_H
double d
Definition: qnumeric_p.h:62
QIntegerForSizeof< void * >::Unsigned quintptr
Definition: qglobal.h:986
#define QT_END_NAMESPACE
This macro expands to.
Definition: qglobal.h:90
~QReadLocker()
Destroys the QReadLocker and unlocks the lock that was passed to the constructor. ...
#define QT_MODULE(x)
Definition: qglobal.h:2783
#define QT_BEGIN_HEADER
Definition: qglobal.h:136
void unlock()
Unlocks the lock.
RecursionMode
QReadWriteLock multiple times and the mutex won&#39;t be unlocked until a corresponding number of unlock(...
void relock()
Relocks an unlocked lock.
#define Q_DISABLE_COPY(Class)
Disables the use of copy constructors and assignment operators for the given Class.
Definition: qglobal.h:2523
quint16 u
QReadWriteLock * readWriteLock() const
Returns a pointer to the read-write lock that was passed to the constructor.
void lockForWrite()
Locks the lock for writing.
void unlock()
Unlocks the lock associated with this locker.
~QWriteLocker()
Destroys the QWriteLocker and unlocks the lock that was passed to the constructor.
QReadWriteLock * readWriteLock() const
Returns a pointer to the read-write lock that was passed to the constructor.
#define QT_BEGIN_NAMESPACE
This macro expands to.
Definition: qglobal.h:89
void lockForRead()
Locks the lock for reading.
The QReadLocker class is a convenience class that simplifies locking and unlocking read-write locks f...
The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks ...
#define Q_ASSERT_X(cond, where, what)
Definition: qglobal.h:1837
#define Q_CORE_EXPORT
Definition: qglobal.h:1449
The QReadWriteLock class provides read-write locking.
#define class
void unlock()
Unlocks the lock associated with this locker.
#define QT_END_HEADER
Definition: qglobal.h:137
#define Q_UNUSED(x)
Indicates to the compiler that the parameter with the specified name is not used in the body of a fun...
Definition: qglobal.h:1729
void relock()
Relocks an unlocked lock.