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author | Petr Mrázek <peterix@gmail.com> | 2016-10-30 02:37:38 +0100 |
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committer | Petr Mrázek <peterix@gmail.com> | 2016-10-30 02:37:38 +0100 |
commit | 412855ae3d967ff81a383688397c4d9448a4ee15 (patch) | |
tree | 78d6225067f39a2696dfb9ca0d40eaed237fe9ee /libraries/LocalPeer/src/LockedFile_win.cpp | |
parent | deabfa78f8e66d1af40d0ecfd787d034cffd5431 (diff) | |
download | MultiMC-412855ae3d967ff81a383688397c4d9448a4ee15.tar MultiMC-412855ae3d967ff81a383688397c4d9448a4ee15.tar.gz MultiMC-412855ae3d967ff81a383688397c4d9448a4ee15.tar.lz MultiMC-412855ae3d967ff81a383688397c4d9448a4ee15.tar.xz MultiMC-412855ae3d967ff81a383688397c4d9448a4ee15.zip |
NOISSUE refactor window management and launch, make MultiMC a single instance application.
Diffstat (limited to 'libraries/LocalPeer/src/LockedFile_win.cpp')
-rw-r--r-- | libraries/LocalPeer/src/LockedFile_win.cpp | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/libraries/LocalPeer/src/LockedFile_win.cpp b/libraries/LocalPeer/src/LockedFile_win.cpp new file mode 100644 index 00000000..3d7d5553 --- /dev/null +++ b/libraries/LocalPeer/src/LockedFile_win.cpp @@ -0,0 +1,205 @@ +/**************************************************************************** +** +** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the Qt Solutions component. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "LockedFile.h" +#include <qt_windows.h> +#include <QFileInfo> + +#define MUTEX_PREFIX "QtLockedFile mutex " +// Maximum number of concurrent read locks. Must not be greater than MAXIMUM_WAIT_OBJECTS +#define MAX_READERS MAXIMUM_WAIT_OBJECTS + +Qt::HANDLE LockedFile::getMutexHandle(int idx, bool doCreate) +{ + if (mutexname.isEmpty()) { + QFileInfo fi(*this); + mutexname = QString::fromLatin1(MUTEX_PREFIX) + + fi.absoluteFilePath().toLower(); + } + QString mname(mutexname); + if (idx >= 0) + mname += QString::number(idx); + + Qt::HANDLE mutex; + if (doCreate) { + mutex = CreateMutexW(NULL, FALSE, (TCHAR*)mname.utf16()); + if (!mutex) { + qErrnoWarning("QtLockedFile::lock(): CreateMutex failed"); + return 0; + } + } + else { + OpenMutexW(SYNCHRONIZE | MUTEX_MODIFY_STATE, FALSE, (TCHAR*)mname.utf16()); + if (!mutex) { + if (GetLastError() != ERROR_FILE_NOT_FOUND) + qErrnoWarning("QtLockedFile::lock(): OpenMutex failed"); + return 0; + } + } + return mutex; +} + +bool LockedFile::waitMutex(Qt::HANDLE mutex, bool doBlock) +{ + Q_ASSERT(mutex); + DWORD res = WaitForSingleObject(mutex, doBlock ? INFINITE : 0); + switch (res) { + case WAIT_OBJECT_0: + case WAIT_ABANDONED: + return true; + break; + case WAIT_TIMEOUT: + break; + default: + qErrnoWarning("QtLockedFile::lock(): WaitForSingleObject failed"); + } + return false; +} + + + +bool LockedFile::lock(LockMode mode, bool block) +{ + if (!isOpen()) { + qWarning("QtLockedFile::lock(): file is not opened"); + return false; + } + + if (mode == NoLock) + return unlock(); + + if (mode == m_lock_mode) + return true; + + if (m_lock_mode != NoLock) + unlock(); + + if (!wmutex && !(wmutex = getMutexHandle(-1, true))) + return false; + + if (!waitMutex(wmutex, block)) + return false; + + if (mode == ReadLock) { + int idx = 0; + for (; idx < MAX_READERS; idx++) { + rmutex = getMutexHandle(idx, false); + if (!rmutex || waitMutex(rmutex, false)) + break; + CloseHandle(rmutex); + } + bool ok = true; + if (idx >= MAX_READERS) { + qWarning("QtLockedFile::lock(): too many readers"); + rmutex = 0; + ok = false; + } + else if (!rmutex) { + rmutex = getMutexHandle(idx, true); + if (!rmutex || !waitMutex(rmutex, false)) + ok = false; + } + if (!ok && rmutex) { + CloseHandle(rmutex); + rmutex = 0; + } + ReleaseMutex(wmutex); + if (!ok) + return false; + } + else { + Q_ASSERT(rmutexes.isEmpty()); + for (int i = 0; i < MAX_READERS; i++) { + Qt::HANDLE mutex = getMutexHandle(i, false); + if (mutex) + rmutexes.append(mutex); + } + if (rmutexes.size()) { + DWORD res = WaitForMultipleObjects(rmutexes.size(), rmutexes.constData(), + TRUE, block ? INFINITE : 0); + if (res != WAIT_OBJECT_0 && res != WAIT_ABANDONED) { + if (res != WAIT_TIMEOUT) + qErrnoWarning("QtLockedFile::lock(): WaitForMultipleObjects failed"); + m_lock_mode = WriteLock; // trick unlock() to clean up - semiyucky + unlock(); + return false; + } + } + } + + m_lock_mode = mode; + return true; +} + +bool LockedFile::unlock() +{ + if (!isOpen()) { + qWarning("QtLockedFile::unlock(): file is not opened"); + return false; + } + + if (!isLocked()) + return true; + + if (m_lock_mode == ReadLock) { + ReleaseMutex(rmutex); + CloseHandle(rmutex); + rmutex = 0; + } + else { + foreach(Qt::HANDLE mutex, rmutexes) { + ReleaseMutex(mutex); + CloseHandle(mutex); + } + rmutexes.clear(); + ReleaseMutex(wmutex); + } + + m_lock_mode = LockedFile::NoLock; + return true; +} + +LockedFile::~LockedFile() +{ + if (isOpen()) + unlock(); + if (wmutex) + CloseHandle(wmutex); +} |