common/include/QtCore/5.5.0/QtCore/private/qwindowspipewriter_p.h

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#ifndef QWINDOWSPIPEWRITER_P_H
#define QWINDOWSPIPEWRITER_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <qelapsedtimer.h>
#include <qthread.h>
#include <qmutex.h>
#include <qwaitcondition.h>
#include <qt_windows.h>

QT_BEGIN_NAMESPACE


#ifndef QT_NO_THREAD

#define SLEEPMIN 10
#define SLEEPMAX 500

class QIncrementalSleepTimer
{

public:
    QIncrementalSleepTimer(int msecs)
        : totalTimeOut(msecs)
        , nextSleep(qMin(SLEEPMIN, totalTimeOut))
    {
        if (totalTimeOut == -1)
            nextSleep = SLEEPMIN;
        timer.start();
    }

    int nextSleepTime()
    {
        int tmp = nextSleep;
        nextSleep = qMin(nextSleep * 2, qMin(SLEEPMAX, timeLeft()));
        return tmp;
    }

    int timeLeft() const
    {
        if (totalTimeOut == -1)
            return SLEEPMAX;
        return qMax(int(totalTimeOut - timer.elapsed()), 0);
    }

    bool hasTimedOut() const
    {
        if (totalTimeOut == -1)
            return false;
        return timer.elapsed() >= totalTimeOut;
    }

    void resetIncrements()
    {
        nextSleep = qMin(SLEEPMIN, timeLeft());
    }

private:
    QElapsedTimer timer;
    int totalTimeOut;
    int nextSleep;
};

class Q_CORE_EXPORT QWindowsPipeWriter : public QThread
{
    Q_OBJECT

Q_SIGNALS:
    void canWrite();
    void bytesWritten(qint64 bytes);

public:
    explicit QWindowsPipeWriter(HANDLE writePipe, QObject * parent = 0);
    ~QWindowsPipeWriter();

    bool waitForWrite(int msecs);
    qint64 write(const char *data, qint64 maxlen);

    qint64 bytesToWrite() const
    {
        QMutexLocker locker(&lock);
        return data.size();
    }

    bool hadWritten() const
    {
        return hasWritten;
    }

protected:
   void run();

private:
    QByteArray data;
    QWaitCondition waitCondition;
    mutable QMutex lock;
    HANDLE writePipe;
    volatile bool quitNow;
    bool hasWritten;
};

#endif //QT_NO_THREAD

QT_END_NAMESPACE

#endif // QT_NO_PROCESS