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8 ** $QT_BEGIN_LICENSE:BSD$
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39 ****************************************************************************/
41 #include "qtlockedfile.h"
42 #include <qt_windows.h>
45 #define MUTEX_PREFIX "QtLockedFile mutex "
46 // Maximum number of concurrent read locks. Must not be greater than MAXIMUM_WAIT_OBJECTS
47 #define MAX_READERS MAXIMUM_WAIT_OBJECTS
49 #define QT_WA(unicode, ansi) unicode
51 Qt::HANDLE QtLockedFile::getMutexHandle(int idx, bool doCreate)
53 if (mutexname.isEmpty()) {
55 mutexname = QString::fromLatin1(MUTEX_PREFIX)
56 + fi.absoluteFilePath().toLower();
58 QString mname(mutexname);
60 mname += QString::number(idx);
64 QT_WA( { mutex = CreateMutexW(NULL, false, (LPCWSTR)mname.utf16()); },
65 { mutex = CreateMutexA(NULL, false, mname.toLocal8Bit().constData()); } );
67 qErrnoWarning("QtLockedFile::lock(): CreateMutex failed");
72 QT_WA( { mutex = OpenMutexW(SYNCHRONIZE | MUTEX_MODIFY_STATE, false, (LPCWSTR)mname.utf16()); },
73 { mutex = OpenMutexA(SYNCHRONIZE | MUTEX_MODIFY_STATE, false, mname.toLocal8Bit().constData()); } );
75 if (GetLastError() != ERROR_FILE_NOT_FOUND)
76 qErrnoWarning("QtLockedFile::lock(): OpenMutex failed");
83 bool QtLockedFile::waitMutex(Qt::HANDLE mutex, bool doBlock)
86 DWORD res = WaitForSingleObject(mutex, doBlock ? INFINITE : 0);
95 qErrnoWarning("QtLockedFile::lock(): WaitForSingleObject failed");
102 bool QtLockedFile::lock(LockMode mode, bool block)
105 qWarning("QtLockedFile::lock(): file is not opened");
112 if (mode == m_lock_mode)
115 if (m_lock_mode != NoLock)
118 if (!wmutex && !(wmutex = getMutexHandle(-1, true)))
121 if (!waitMutex(wmutex, block))
124 if (mode == ReadLock) {
126 for (; idx < MAX_READERS; idx++) {
127 rmutex = getMutexHandle(idx, false);
128 if (!rmutex || waitMutex(rmutex, false))
133 if (idx >= MAX_READERS) {
134 qWarning("QtLockedFile::lock(): too many readers");
139 rmutex = getMutexHandle(idx, true);
140 if (!rmutex || !waitMutex(rmutex, false))
147 ReleaseMutex(wmutex);
152 Q_ASSERT(rmutexes.isEmpty());
153 for (int i = 0; i < MAX_READERS; i++) {
154 Qt::HANDLE mutex = getMutexHandle(i, false);
156 rmutexes.append(mutex);
158 if (rmutexes.size()) {
159 DWORD res = WaitForMultipleObjects(rmutexes.size(), rmutexes.constData(),
160 true, block ? INFINITE : 0);
161 if (res != WAIT_OBJECT_0 && res != WAIT_ABANDONED) {
162 if (res != WAIT_TIMEOUT)
163 qErrnoWarning("QtLockedFile::lock(): WaitForMultipleObjects failed");
164 m_lock_mode = WriteLock; // trick unlock() to clean up - semiyucky
175 bool QtLockedFile::unlock()
178 qWarning("QtLockedFile::unlock(): file is not opened");
185 if (m_lock_mode == ReadLock) {
186 ReleaseMutex(rmutex);
191 foreach(Qt::HANDLE mutex, rmutexes) {
196 ReleaseMutex(wmutex);
199 m_lock_mode = QtLockedFile::NoLock;
203 QtLockedFile::~QtLockedFile()