masterthread.cpp Example File | Qt Serial Port 5.6

Qt 5.6 | Qt Serial Port | Blocking Master Example | masterthread.cpp Example File

Qt 5.6.2 Reference Documentation

# masterthread.cpp Example File

blockingmaster/masterthread.cpp

      /****************************************************************************
      **
      ** 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
      ** and conditions see http://www.qt.io/terms-conditions. For further
      ** 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
      ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
      ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
      **
      ** As a special exception, The Qt Company gives you certain additional
      ** rights. These rights are described in The Qt Company LGPL Exception
      ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #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();
          }
      }