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authorPetr Mrázek <peterix@gmail.com>2016-10-30 02:37:38 +0100
committerPetr Mrázek <peterix@gmail.com>2016-10-30 02:37:38 +0100
commit412855ae3d967ff81a383688397c4d9448a4ee15 (patch)
tree78d6225067f39a2696dfb9ca0d40eaed237fe9ee /libraries/LocalPeer/src/LockedFile_win.cpp
parentdeabfa78f8e66d1af40d0ecfd787d034cffd5431 (diff)
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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.cpp205
1 files changed, 205 insertions, 0 deletions
diff --git a/libraries/LocalPeer/src/LockedFile_win.cpp b/libraries/LocalPeer/src/LockedFile_win.cpp
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+++ b/libraries/LocalPeer/src/LockedFile_win.cpp
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+/****************************************************************************
+**
+** 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);
+}