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39 
40 #ifndef QSHAREDMEMORY_P_H
41 #define QSHAREDMEMORY_P_H
42 
43 //
44 //  W A R N I N G
45 //  -------------
46 //
47 // This file is not part of the Qt API.  It exists purely as an
48 // implementation detail.  This header file may change from version to
49 // version without notice, or even be removed.
50 //
51 // We mean it.
52 //
53 
54 #include "qsharedmemory.h"
55 
56 #include <QtCore/qstring.h>
57 
58 #ifdef QT_NO_SHAREDMEMORY
59 # ifndef QT_NO_SYSTEMSEMAPHORE
60 namespace QSharedMemoryPrivate
61 {
62     int createUnixKeyFile(const QString &fileName);
63     QString makePlatformSafeKey(const QString &key,
64             const QString &prefix = QLatin1String("qipc_sharedmemory_"));
65 }
66 #endif
67 #else
68 
69 #include "qsystemsemaphore.h"
70 
71 #ifndef QT_NO_QOBJECT
72 # include "private/qobject_p.h"
73 #endif
74 
75 #if !defined(Q_OS_WIN) && !defined(Q_OS_ANDROID) && !defined(Q_OS_INTEGRITY) && !defined(Q_OS_RTEMS)
76 #  include <sys/sem.h>
77 #endif
78 
79 QT_BEGIN_NAMESPACE
80 
81 #ifndef QT_NO_SYSTEMSEMAPHORE
82 /*!
83   Helper class
84   */
85 class QSharedMemoryLocker
86 {
87 
88 public:
QSharedMemoryLocker(QSharedMemory * sharedMemory)89     inline QSharedMemoryLocker(QSharedMemory *sharedMemory) : q_sm(sharedMemory)
90     {
91         Q_ASSERT(q_sm);
92     }
93 
~QSharedMemoryLocker()94     inline ~QSharedMemoryLocker()
95     {
96         if (q_sm)
97             q_sm->unlock();
98     }
99 
lock()100     inline bool lock()
101     {
102         if (q_sm && q_sm->lock())
103             return true;
104         q_sm = nullptr;
105         return false;
106     }
107 
108 private:
109     QSharedMemory *q_sm;
110 };
111 #endif // QT_NO_SYSTEMSEMAPHORE
112 
113 class Q_AUTOTEST_EXPORT QSharedMemoryPrivate
114 #ifndef QT_NO_QOBJECT
115         : public QObjectPrivate
116 #endif
117 {
118 #ifndef QT_NO_QOBJECT
119     Q_DECLARE_PUBLIC(QSharedMemory)
120 #endif
121 
122 public:
123     QSharedMemoryPrivate();
124 
125     void *memory;
126     int size;
127     QString key;
128     QString nativeKey;
129     QSharedMemory::SharedMemoryError error;
130     QString errorString;
131 #ifndef QT_NO_SYSTEMSEMAPHORE
132     QSystemSemaphore systemSemaphore;
133     bool lockedByMe;
134 #endif
135 
136     static int createUnixKeyFile(const QString &fileName);
137     static QString makePlatformSafeKey(const QString &key,
138             const QString &prefix = QLatin1String("qipc_sharedmemory_"));
139 #ifdef Q_OS_WIN
140     Qt::HANDLE handle();
141 #elif defined(QT_POSIX_IPC)
142     int handle();
143 #else
144     key_t handle();
145 #endif
146     bool initKey();
147     bool cleanHandle();
148     bool create(int size);
149     bool attach(QSharedMemory::AccessMode mode);
150     bool detach();
151 
152     void setErrorString(QLatin1String function);
153 
154 #ifndef QT_NO_SYSTEMSEMAPHORE
tryLocker(QSharedMemoryLocker * locker,const QString & function)155     bool tryLocker(QSharedMemoryLocker *locker, const QString &function) {
156         if (!locker->lock()) {
157             errorString = QSharedMemory::tr("%1: unable to lock").arg(function);
158             error = QSharedMemory::LockError;
159             return false;
160         }
161         return true;
162     }
163 #endif // QT_NO_SYSTEMSEMAPHORE
164 
165 private:
166 #ifdef Q_OS_WIN
167     Qt::HANDLE hand;
168 #elif defined(QT_POSIX_IPC)
169     int hand;
170 #else
171     key_t unix_key;
172 #endif
173 };
174 
175 QT_END_NAMESPACE
176 
177 #endif // QT_NO_SHAREDMEMORY
178 
179 #endif // QSHAREDMEMORY_P_H
180 
181