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41 
42 #ifndef QWSLOCK_P_H
43 #define QWSLOCK_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 <qglobal.h>
57 
58 #ifndef QT_NO_QWS_MULTIPROCESS
59 
60 #ifdef QT_POSIX_IPC
61 #  include <semaphore.h>
62 #endif
63 
64 QT_BEGIN_NAMESPACE
65 
66 class QWSLock
67 {
68 public:
69     enum LockType { BackingStore, Communication, RegionEvent };
70 
71     QWSLock(int lockId = -1);
72     ~QWSLock();
73 
74     bool lock(LockType type, int timeout = -1);
75     void unlock(LockType type);
76     bool wait(LockType type, int timeout = -1);
77     bool hasLock(LockType type);
id()78     int id() const { return semId; }
79 
80 private:
81     bool up(unsigned short semNum);
82     bool down(unsigned short semNum, int timeout);
83     int getValue(unsigned short semNum) const;
84 
85     int semId;
86     int lockCount[2];
87 #ifdef QT_POSIX_IPC
88     sem_t *sems[3];
89     bool owned;
90 #endif
91 };
92 
93 QT_END_NAMESPACE
94 
95 #endif // QT_NO_QWS_MULTIPROCESS
96 
97 #endif // QWSLOCK_P_H
98