mirror of
https://github.com/clementine-player/Clementine
synced 2024-12-23 08:20:01 +01:00
215 lines
6.6 KiB
C++
215 lines
6.6 KiB
C++
/****************************************************************************
|
|
**
|
|
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
|
|
** All rights reserved.
|
|
**
|
|
** Contact: Nokia Corporation (qt-info@nokia.com)
|
|
**
|
|
** This file is part of a Qt Solutions component.
|
|
**
|
|
** 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 Nokia Corporation 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."
|
|
**
|
|
****************************************************************************/
|
|
|
|
#include "qtlockedfile.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 QtLockedFile::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) {
|
|
#if (QT_VERSION < 0x050000)
|
|
QT_WA( { mutex = CreateMutexW(NULL, FALSE, (TCHAR*)mname.utf16()); },
|
|
{ mutex = CreateMutexA(NULL, FALSE, mname.toLocal8Bit().constData()); } );
|
|
#else
|
|
mutex = CreateMutexW(NULL, FALSE, (TCHAR*)mname.utf16());
|
|
#endif
|
|
if (!mutex) {
|
|
qErrnoWarning("QtLockedFile::lock(): CreateMutex failed");
|
|
return 0;
|
|
}
|
|
}
|
|
else {
|
|
#if (QT_VERSION < 0x050000)
|
|
QT_WA( { mutex = OpenMutexW(SYNCHRONIZE | MUTEX_MODIFY_STATE, FALSE, (TCHAR*)mname.utf16()); },
|
|
{ mutex = OpenMutexA(SYNCHRONIZE | MUTEX_MODIFY_STATE, FALSE, mname.toLocal8Bit().constData()); } );
|
|
#else
|
|
mutex = OpenMutexW(SYNCHRONIZE | MUTEX_MODIFY_STATE, FALSE, (TCHAR*)mname.utf16());
|
|
#endif
|
|
if (!mutex) {
|
|
if (GetLastError() != ERROR_FILE_NOT_FOUND)
|
|
qErrnoWarning("QtLockedFile::lock(): OpenMutex failed");
|
|
return 0;
|
|
}
|
|
}
|
|
return mutex;
|
|
}
|
|
|
|
bool QtLockedFile::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 QtLockedFile::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 QtLockedFile::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 = QtLockedFile::NoLock;
|
|
return true;
|
|
}
|
|
|
|
QtLockedFile::~QtLockedFile()
|
|
{
|
|
if (isOpen())
|
|
unlock();
|
|
if (wmutex)
|
|
CloseHandle(wmutex);
|
|
}
|