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39
40 #include "qsharedmemory.h"
41 #include "qsharedmemory_p.h"
42 #include "qsystemsemaphore.h"
43 #include <qdebug.h>
44 #include <qt_windows.h>
45
46 QT_BEGIN_NAMESPACE
47
48 #ifndef QT_NO_SHAREDMEMORY
49
QSharedMemoryPrivate()50 QSharedMemoryPrivate::QSharedMemoryPrivate() :
51 #ifndef QT_NO_QOBJECT
52 QObjectPrivate(),
53 #endif
54 memory(0), size(0), error(QSharedMemory::NoError),
55 systemSemaphore(QString()), lockedByMe(false), hand(0)
56 {
57 }
58
setErrorString(QLatin1String function)59 void QSharedMemoryPrivate::setErrorString(QLatin1String function)
60 {
61 DWORD windowsError = GetLastError();
62 if (windowsError == 0)
63 return;
64 switch (windowsError) {
65 case ERROR_ALREADY_EXISTS:
66 error = QSharedMemory::AlreadyExists;
67 errorString = QSharedMemory::tr("%1: already exists").arg(function);
68 break;
69 case ERROR_FILE_NOT_FOUND:
70 error = QSharedMemory::NotFound;
71 errorString = QSharedMemory::tr("%1: doesn't exist").arg(function);
72 break;
73 case ERROR_COMMITMENT_LIMIT:
74 error = QSharedMemory::InvalidSize;
75 errorString = QSharedMemory::tr("%1: invalid size").arg(function);
76 break;
77 case ERROR_NO_SYSTEM_RESOURCES:
78 case ERROR_NOT_ENOUGH_MEMORY:
79 error = QSharedMemory::OutOfResources;
80 errorString = QSharedMemory::tr("%1: out of resources").arg(function);
81 break;
82 case ERROR_ACCESS_DENIED:
83 error = QSharedMemory::PermissionDenied;
84 errorString = QSharedMemory::tr("%1: permission denied").arg(function);
85 break;
86 default:
87 errorString = QSharedMemory::tr("%1: unknown error %2").arg(function).arg(windowsError);
88 error = QSharedMemory::UnknownError;
89 #if defined QSHAREDMEMORY_DEBUG
90 qDebug() << errorString << "key" << key;
91 #endif
92 }
93 }
94
handle()95 HANDLE QSharedMemoryPrivate::handle()
96 {
97 if (!hand) {
98 const QLatin1String function("QSharedMemory::handle");
99 if (nativeKey.isEmpty()) {
100 error = QSharedMemory::KeyError;
101 errorString = QSharedMemory::tr("%1: unable to make key").arg(function);
102 return 0;
103 }
104 #if defined(Q_OS_WINRT)
105 hand = OpenFileMappingFromApp(FILE_MAP_ALL_ACCESS, FALSE, reinterpret_cast<PCWSTR>(nativeKey.utf16()));
106 #else
107 hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false,
108 reinterpret_cast<const wchar_t*>(nativeKey.utf16()));
109 #endif
110 if (!hand) {
111 setErrorString(function);
112 return 0;
113 }
114 }
115 return hand;
116 }
117
cleanHandle()118 bool QSharedMemoryPrivate::cleanHandle()
119 {
120 if (hand != 0 && !CloseHandle(hand)) {
121 hand = 0;
122 setErrorString(QLatin1String("QSharedMemory::cleanHandle"));
123 return false;
124 }
125 hand = 0;
126 return true;
127 }
128
create(int size)129 bool QSharedMemoryPrivate::create(int size)
130 {
131 const QLatin1String function("QSharedMemory::create");
132 if (nativeKey.isEmpty()) {
133 error = QSharedMemory::KeyError;
134 errorString = QSharedMemory::tr("%1: key error").arg(function);
135 return false;
136 }
137
138 // Create the file mapping.
139 #if defined(Q_OS_WINRT)
140 hand = CreateFileMappingFromApp(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, size,
141 reinterpret_cast<PCWSTR>(nativeKey.utf16()));
142 #else
143 hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size,
144 reinterpret_cast<const wchar_t*>(nativeKey.utf16()));
145 #endif
146 setErrorString(function);
147
148 // hand is valid when it already exists unlike unix so explicitly check
149 return error != QSharedMemory::AlreadyExists && hand;
150 }
151
attach(QSharedMemory::AccessMode mode)152 bool QSharedMemoryPrivate::attach(QSharedMemory::AccessMode mode)
153 {
154 // Grab a pointer to the memory block
155 int permissions = (mode == QSharedMemory::ReadOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS);
156 #if defined(Q_OS_WINRT)
157 memory = (void *)MapViewOfFileFromApp(handle(), permissions, 0, 0);
158 #else
159 memory = (void *)MapViewOfFile(handle(), permissions, 0, 0, 0);
160 #endif
161 if (0 == memory) {
162 setErrorString(QLatin1String("QSharedMemory::attach"));
163 cleanHandle();
164 return false;
165 }
166
167 // Grab the size of the memory we have been given (a multiple of 4K on windows)
168 MEMORY_BASIC_INFORMATION info;
169 if (!VirtualQuery(memory, &info, sizeof(info))) {
170 // Windows doesn't set an error code on this one,
171 // it should only be a kernel memory error.
172 error = QSharedMemory::UnknownError;
173 errorString = QSharedMemory::tr("%1: size query failed").arg(QLatin1String("QSharedMemory::attach: "));
174 return false;
175 }
176 size = info.RegionSize;
177
178 return true;
179 }
180
detach()181 bool QSharedMemoryPrivate::detach()
182 {
183 // umap memory
184 if (!UnmapViewOfFile(memory)) {
185 setErrorString(QLatin1String("QSharedMemory::detach"));
186 return false;
187 }
188 memory = 0;
189 size = 0;
190
191 // close handle
192 return cleanHandle();
193 }
194
195 #endif //QT_NO_SHAREDMEMORY
196
197
198 QT_END_NAMESPACE
199