I have a QTcpSocket and I am reading into a loop. Each time a full packet has been read, or there has been an error, I manually check the status of the socket inside the loop, with:
while(true){
if(socket->state()==QAbstractSocket::ConnectedState){
qDebug()<<"Socket status: connected. Looking for packets...";
if(socket->waitForReadyRead(2000)){
//...
}
When I execute de program, once connected and the loop starts, it always prints qDebug()<<"Socket status: connected. Looking for packets..."
; and then stucks at waitForReadyRead
until some data is ready to be read.
The problem is that disconnections are not detected. If I disconnect from network from the OS options, or even if I unplug the ethernet wire, it behaves the same: Socket state equals QAbstractSocket::ConnectedStat
e, so it goes on, but without receiving anything of course.
I also tried to detect disconnections connecting disconnected()
signal (after fist connection) to a reconnect function:
// Detect disconnection in order to reconnect
connect(socket, SIGNAL(disconnected()), this, SLOT(reconnect()));
void MyClass::reconnect(){
qDebug()<<"Signal DISCONNECTED emitted. Now trying to reconnect";
panelGUI->mostrarValueOffline();
socket->close();
prepareSocket((Global::directionIPSerialServer).toLocal8Bit().data(), 8008, socket);
qDebug()<<"Reconnected? Status: "<<socket->state();
}
But signal is never emited, because this code is never executed. Which is logical, since it looks like socket state is always ConnectedState
.
If I plug again, connection is restored and starts to receive data again, but I do want to detect disconnections to show "Disconnected" at the GUI.
Why is QTcpSocket behaving this way, and how can I solve this problem?
EDIT: I'm creating socket at the class constructor, and then initialising calling prepareSocket function:
socket = new QTcpSocket();
socket->moveToThread(this);
bool prepareSocket(QString address, int port, QTcpSocket *socket) {
socket->connectToHost(address, port);
if(!socket->waitForConnected(2000)){
qDebug()<<"Error creating socket: "<<socket->errorString();
sleep(1);
return false;
}
return true;
}