text: /****************************************************************************
  **
  ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
  ** All rights reserved.
  ** Contact: Nokia Corporation (qt-info@nokia.com)
  **
  ** This file is part of the QtCore module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
  ** GNU Lesser General Public License Usage
  ** This file may be used under the terms of the GNU Lesser General Public
  ** License version 2.1 as published by the Free Software Foundation and
  ** appearing in the file LICENSE.LGPL included in the packaging of this
  ** file. Please review the following information to ensure the GNU Lesser
  ** General Public License version 2.1 requirements will be met:
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  **
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  ** rights. These rights are described in the Nokia Qt LGPL Exception
  ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU General
  ** Public License version 3.0 as published by the Free Software Foundation
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  ** file. Please review the following information to ensure the GNU General
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  ** http://www.gnu.org/copyleft/gpl.html.
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  ** Alternatively, this file may be used in accordance with the terms and
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  **
  **
  **
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/
  
  #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 <qdatetime.h>
  #include <qthread.h>
  #include <qmutex.h>
  #include <qwaitcondition.h>
  #include <qt_windows.h>
  
  QT_BEGIN_HEADER
  
  QT_BEGIN_NAMESPACE
  
  QT_MODULE(Core)
  
  #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(totalTimeOut - timer.elapsed(), 0);
      }
  
      bool hasTimedOut() const
      {
          if (totalTimeOut == -1)
              return false;
          return timer.elapsed() >= totalTimeOut;
      }
  
      void resetIncrements()
      {
          nextSleep = qMin(SLEEPMIN, timeLeft());
      }
  
  private:
      QTime timer;
      int totalTimeOut;
      int nextSleep;
  };
  
  class Q_CORE_EXPORT QWindowsPipeWriter : public QThread
  {
      Q_OBJECT
  
  Q_SIGNALS:
      void canWrite();
      void bytesWritten(qint64 bytes);
  
  public:
      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
  
  QT_END_HEADER
  
  #endif // QT_NO_PROCESS
  