source: smplayer/trunk/src/qtsingleapplication/qtlockedfile.h

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#ifndef QTLOCKEDFILE_H
#define QTLOCKEDFILE_H

#include <QFile>
#ifdef Q_OS_WIN
#include <QVector>
#endif

#if defined(Q_OS_WIN)
#  if !defined(QT_QTLOCKEDFILE_EXPORT) && !defined(QT_QTLOCKEDFILE_IMPORT)
#    define QT_QTLOCKEDFILE_EXPORT
#  elif defined(QT_QTLOCKEDFILE_IMPORT)
#    if defined(QT_QTLOCKEDFILE_EXPORT)
#      undef QT_QTLOCKEDFILE_EXPORT
#    endif
#    define QT_QTLOCKEDFILE_EXPORT __declspec(dllimport)
#  elif defined(QT_QTLOCKEDFILE_EXPORT)
#    undef QT_QTLOCKEDFILE_EXPORT
#    define QT_QTLOCKEDFILE_EXPORT __declspec(dllexport)
#  endif
#else
#  define QT_QTLOCKEDFILE_EXPORT
#endif

namespace QtLP_Private {

class QT_QTLOCKEDFILE_EXPORT QtLockedFile : public QFile
{
public:
    enum LockMode { NoLock = 0, ReadLock, WriteLock };

    QtLockedFile();
    QtLockedFile(const QString &name);
    ~QtLockedFile();

    bool open(OpenMode mode);

    bool lock(LockMode mode, bool block = true);
    bool unlock();
    bool isLocked() const;
    LockMode lockMode() const;

private:
#ifdef Q_OS_WIN
    Qt::HANDLE wmutex;
    Qt::HANDLE rmutex;
    QVector<Qt::HANDLE> rmutexes;
    QString mutexname;

    Qt::HANDLE getMutexHandle(int idx, bool doCreate);
    bool waitMutex(Qt::HANDLE mutex, bool doBlock);

#endif
    LockMode m_lock_mode;
};
}
#endif