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41 
42 #ifndef QLOCK_P_H
43 #define QLOCK_P_H
44 
45 //
46 //  W A R N I N G
47 //  -------------
48 //
49 // This file is not part of the Qt API.  This header file may
50 // change from version to version without notice, or even be
51 // removed.
52 //
53 // We mean it.
54 //
55 
56 #include "QtCore/qstring.h"
57 
58 QT_BEGIN_NAMESPACE
59 
60 class QLockData;
61 
62 class Q_GUI_EXPORT QLock
63 {
64 public:
65     QLock(const QString &filename, char id, bool create = false);
66     ~QLock();
67 
68     enum Type { Read, Write };
69 
70     bool isValid() const;
71     void lock(Type type);
72     void unlock();
73     bool locked() const;
74 
75 private:
76     Type type;
77     QLockData *data;
78 };
79 
80 
81 // Nice class for ensuring the lock is released.
82 // Just create one on the stack and the lock is automatically released
83 // when QLockHandle is destructed.
84 class Q_GUI_EXPORT QLockHandle
85 {
86 public:
QLockHandle(QLock * l,QLock::Type type)87     QLockHandle(QLock *l, QLock::Type type) : qlock(l) { qlock->lock(type); }
~QLockHandle()88     ~QLockHandle() { if (locked()) qlock->unlock(); }
89 
lock(QLock::Type type)90     void lock(QLock::Type type) { qlock->lock(type); }
unlock()91     void unlock() { qlock->unlock(); }
locked()92     bool locked() const { return qlock->locked(); }
93 
94 private:
95     QLock *qlock;
96 };
97 
98 QT_END_NAMESPACE
99 
100 #endif // QLOCK_P_H
101