diff options
Diffstat (limited to 'src/shared/qtlockedfile/qtlockedfile_win.cpp')
| -rw-r--r-- | src/shared/qtlockedfile/qtlockedfile_win.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/shared/qtlockedfile/qtlockedfile_win.cpp b/src/shared/qtlockedfile/qtlockedfile_win.cpp new file mode 100644 index 0000000000..f1d74e30fc --- /dev/null +++ b/src/shared/qtlockedfile/qtlockedfile_win.cpp @@ -0,0 +1,207 @@ +/*************************************************************************** +** +** 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 |