Qt C++ code crash (ASSERT: *node == e)

Vyuvaraj

What is reason behind the below error message

ASSERT: "*node == e || (*node)->next" in file ....\include/QtCore/../../src/corelib/tools/qhash.h, line 918
11:43:02: The program has unexpectedly finished.
11:43:02: The process was ended forcefully.

I have tcp client socket which received 74 bytes of data from server @ 20mSec interval.
I'm collecting the data using queue and emitting @ every 50mSec interval to other C++ backend class which does processing of the data.
I'm doubtful if the processing on the backend class is causing the issue?
How to debug the crash and collect crash log?

Christian Ehrlicher

@Vyuvaraj said in Qt C++ code crash (ASSERT: *node == e):

How to debug the crash and collect crash log?

Use a debugger and take a look at the backtrace to see where it comes from. Are you using threads?

fcarney

Code Please

Vyuvaraj

@fcarney

bool m_quit = false;
bool m_InProcess = false;
QTcpSocket *m_sock = nullptr;

tpClient::tpClient(QObject *parent) : QThread(parent) {
   m_InProcess = false;
   m_sock = new QTcpSocket(this);
   connect(m_sock, SIGNAL(connected()), this, SLOT(connected()));
   connect(m_sock, SIGNAL(disconnected()), this, SLOT(disconnected()));
   connect(m_sock, SIGNAL(readyRead()), this, SLOT(readyRead()));
   m_sock->abort();
   m_sock->connectToHost("127.0.0.1",51001);
}

void tpClient::connected() { if(!isRunning()){start();} }

void tpClient::readyRead() { m_dataInQ.push(m_sock->readAll()); }

void tpClient::run(void) {
  qDebug() <<  "Thread is Running...";
  while(!m_quit){
    while(!m_dataInQ.empty() && !m_InProcess){
    /* This will allow the rendering engine to achieve a consistent 60 frames-per-second refresh rate.
        60 FPS means that there is approximately 16 milliseconds.
        Provide 2 times more for safety */
    msleep(32);

    if(m_mutex.tryLockForRead(1000)) {
      QByteArray data = m_dataInQ.front();
      m_dataInQ.pop();
      m_mutex.unlock();
      processInput(processRawInput(data));
    }   
  }

  msleep(10); 
  }
}

Christian Ehrlicher

Please read the QThread docs - you're doing it wrong, the examples and docs give you a good starting point...