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-rw-r--r--src/shared/qtlockedfile/qtlockedfile_win.cpp207
1 files changed, 207 insertions, 0 deletions
diff --git a/src/shared/qtlockedfile/qtlockedfile_win.cpp b/src/shared/qtlockedfile/qtlockedfile_win.cpp
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+++ b/src/shared/qtlockedfile/qtlockedfile_win.cpp
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+/***************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+**
+** Non-Open Source Usage
+**
+** Licensees may use this file in accordance with the Qt Beta Version
+** License Agreement, Agreement version 2.2 provided with the Software or,
+** alternatively, in accordance with the terms contained in a written
+** agreement between you and Nokia.
+**
+** GNU General Public License Usage
+**
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License versions 2.0 or 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the packaging
+** of this file. Please review the following information to ensure GNU
+** General Public Licensing requirements will be met:
+**
+** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt GPL Exception
+** version 1.3, included in the file GPL_EXCEPTION.txt in this package.
+**
+***************************************************************************/
+
+#include "qtlockedfile.h"
+
+#include <qt_windows.h>
+#include <QtCore/QFileInfo>
+
+namespace SharedTools {
+
+#define SEMAPHORE_PREFIX "QtLockedFile semaphore "
+#define MUTEX_PREFIX "QtLockedFile mutex "
+#define SEMAPHORE_MAX 100
+
+static QString errorCodeToString(DWORD errorCode)
+{
+ QString result;
+ char *data = 0;
+ FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+ 0, errorCode, 0,
+ (char*)&data, 0, 0);
+ result = QString::fromLocal8Bit(data);
+ if (data != 0)
+ LocalFree(data);
+
+ if (result.endsWith("\n"))
+ result.truncate(result.length() - 1);
+
+ return result;
+}
+
+bool QtLockedFile::lock(LockMode mode, bool block)
+{
+ if (!isOpen()) {
+ qWarning("QtLockedFile::lock(): file is not opened");
+ return false;
+ }
+
+ if (mode == m_lock_mode)
+ return true;
+
+ if (m_lock_mode != 0)
+ unlock();
+
+ if (m_semaphore_hnd == 0) {
+ QFileInfo fi(*this);
+ QString sem_name = QString::fromLatin1(SEMAPHORE_PREFIX)
+ + fi.absoluteFilePath().toLower();
+
+ QT_WA( {
+ m_semaphore_hnd = CreateSemaphoreW(0, SEMAPHORE_MAX, SEMAPHORE_MAX,
+ (TCHAR*)sem_name.utf16());
+ } , {
+ m_semaphore_hnd = CreateSemaphoreA(0, SEMAPHORE_MAX, SEMAPHORE_MAX,
+ sem_name.toLocal8Bit().constData());
+ } );
+
+ if (m_semaphore_hnd == 0) {
+ qWarning("QtLockedFile::lock(): CreateSemaphore: %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ return false;
+ }
+ }
+
+ bool gotMutex = false;
+ int decrement;
+ if (mode == ReadLock) {
+ decrement = 1;
+ } else {
+ decrement = SEMAPHORE_MAX;
+ if (m_mutex_hnd == 0) {
+ QFileInfo fi(*this);
+ QString mut_name = QString::fromLatin1(MUTEX_PREFIX)
+ + fi.absoluteFilePath().toLower();
+ QT_WA( {
+ m_mutex_hnd = CreateMutexW(NULL, FALSE, (TCHAR*)mut_name.utf16());
+ } , {
+ m_mutex_hnd = CreateMutexA(NULL, FALSE, mut_name.toLocal8Bit().constData());
+ } );
+
+ if (m_mutex_hnd == 0) {
+ qWarning("QtLockedFile::lock(): CreateMutex: %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ return false;
+ }
+ }
+ DWORD res = WaitForSingleObject(m_mutex_hnd, block ? INFINITE : 0);
+ if (res == WAIT_TIMEOUT)
+ return false;
+ if (res == WAIT_FAILED) {
+ qWarning("QtLockedFile::lock(): WaitForSingleObject (mutex): %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ return false;
+ }
+ gotMutex = true;
+ }
+
+ for (int i = 0; i < decrement; ++i) {
+ DWORD res = WaitForSingleObject(m_semaphore_hnd, block ? INFINITE : 0);
+ if (res == WAIT_TIMEOUT) {
+ if (i) {
+ // A failed nonblocking rw locking. Undo changes to semaphore.
+ if (ReleaseSemaphore(m_semaphore_hnd, i, NULL) == 0) {
+ qWarning("QtLockedFile::unlock(): ReleaseSemaphore: %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ // Fall through
+ }
+ }
+ if (gotMutex)
+ ReleaseMutex(m_mutex_hnd);
+ return false;
+ }
+ if (res != WAIT_OBJECT_0) {
+ if (gotMutex)
+ ReleaseMutex(m_mutex_hnd);
+ qWarning("QtLockedFile::lock(): WaitForSingleObject (semaphore): %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ return false;
+ }
+ }
+
+ m_lock_mode = mode;
+ if (gotMutex)
+ ReleaseMutex(m_mutex_hnd);
+ return true;
+}
+
+bool QtLockedFile::unlock()
+{
+ if (!isOpen()) {
+ qWarning("QtLockedFile::unlock(): file is not opened");
+ return false;
+ }
+
+ if (!isLocked())
+ return true;
+
+ int increment;
+ if (m_lock_mode == ReadLock)
+ increment = 1;
+ else
+ increment = SEMAPHORE_MAX;
+
+ DWORD ret = ReleaseSemaphore(m_semaphore_hnd, increment, 0);
+ if (ret == 0) {
+ qWarning("QtLockedFile::unlock(): ReleaseSemaphore: %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ return false;
+ }
+
+ m_lock_mode = QtLockedFile::NoLock;
+ return true;
+}
+
+QtLockedFile::~QtLockedFile()
+{
+ if (isOpen())
+ unlock();
+ if (m_mutex_hnd != 0) {
+ DWORD ret = CloseHandle(m_mutex_hnd);
+ if (ret == 0) {
+ qWarning("QtLockedFile::~QtLockedFile(): CloseHandle (mutex): %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ }
+ m_mutex_hnd = 0;
+ }
+ if (m_semaphore_hnd != 0) {
+ DWORD ret = CloseHandle(m_semaphore_hnd);
+ if (ret == 0) {
+ qWarning("QtLockedFile::~QtLockedFile(): CloseHandle (semaphore): %s",
+ errorCodeToString(GetLastError()).toLatin1().constData());
+ }
+ m_semaphore_hnd = 0;
+ }
+}
+
+} // namespace SharedTools