masterthread.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2012 Denis Shienkov <denis.shienkov@gmail.com>
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the QtSerialPort module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL21$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
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  ** information use the contact form at http://www.qt.io/contact-us.
  **
  ** GNU Lesser General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU Lesser
  ** General Public License version 2.1 or version 3 as published by the Free
  ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
  ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
  ** following information to ensure the GNU Lesser General Public License
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  ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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  ****************************************************************************/

  #include "masterthread.h"

  #include <QtSerialPort/QSerialPort>

  #include <QTime>

  QT_USE_NAMESPACE

  MasterThread::MasterThread(QObject *parent)
      : QThread(parent), waitTimeout(0), quit(false)
  {
  }

  MasterThread::~MasterThread()
  {
      mutex.lock();
      quit = true;
      cond.wakeOne();
      mutex.unlock();
      wait();
  }

  void MasterThread::transaction(const QString &portName, int waitTimeout, const QString &request)
  {
      QMutexLocker locker(&mutex);
      this->portName = portName;
      this->waitTimeout = waitTimeout;
      this->request = request;
      if (!isRunning())
          start();
      else
          cond.wakeOne();
  }

  void MasterThread::run()
  {
      bool currentPortNameChanged = false;

      mutex.lock();
      QString currentPortName;
      if (currentPortName != portName) {
          currentPortName = portName;
          currentPortNameChanged = true;
      }

      int currentWaitTimeout = waitTimeout;
      QString currentRequest = request;
      mutex.unlock();
      QSerialPort serial;

      while (!quit) {
          if (currentPortNameChanged) {
              serial.close();
              serial.setPortName(currentPortName);

              if (!serial.open(QIODevice::ReadWrite)) {
                  emit error(tr("Can't open %1, error code %2")
                             .arg(portName).arg(serial.error()));
                  return;
              }
          }
          // write request
          QByteArray requestData = currentRequest.toLocal8Bit();
          serial.write(requestData);
          if (serial.waitForBytesWritten(waitTimeout)) {
              // read response
              if (serial.waitForReadyRead(currentWaitTimeout)) {
                  QByteArray responseData = serial.readAll();
                  while (serial.waitForReadyRead(10))
                      responseData += serial.readAll();

                  QString response(responseData);
                  emit this->response(response);
              } else {
                  emit timeout(tr("Wait read response timeout %1")
                               .arg(QTime::currentTime().toString()));
              }
          } else {
              emit timeout(tr("Wait write request timeout %1")
                           .arg(QTime::currentTime().toString()));
          }
          mutex.lock();
          cond.wait(&mutex);
          if (currentPortName != portName) {
              currentPortName = portName;
              currentPortNameChanged = true;
          } else {
              currentPortNameChanged = false;
          }
          currentWaitTimeout = waitTimeout;
          currentRequest = request;
          mutex.unlock();
      }
  }