QTcpSocket->readAll() doesn't have anything to read!

[naturalpsychic]

I have server and client in the same client/server architecture application.

First send
Server::incommingConnection()
Buffering
"Task::handleTask strBuffer= taskToHandle---received from localhost:1591"

"RequestManager::send() response SENDING TO: localhost:1591"
RequestManager::send() CONNECTING...
RequestManager::send() CONNECTED
RequestManager::send() SENT!
New client connected


is debug output


now my problem is that it stops at New client connected and doesn't goto readyRead() infact even when I explicitely call readyRead() [my slot connected to QTcpSocket's readyRead signal] readAll() has nothing in it

following diagram is better way of describing of whats happening:

server_response.png

Following are some bits of my code:

void Server::incomingConnection(const int socketDescriptor)
{
#if (DEBUGGING)
    qDebug()<<"Server::incommingConnection()";
#endif
    client=new NetworkObjects::Client(socketDescriptor,parent_);
 
}

void Server::incomingConnection(const int socketDescriptor)
{
#if (DEBUGGING)
    qDebug()<<"Server::incommingConnection()";
#endif
    client=new NetworkObjects::Client(socketDescriptor,parent_);

}

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Client::Client(const int socketDescriptor,QObject *parent) :
    QObject(parent),
    parent_(parent)
{
    setSocketDescriptor(socketDescriptor);
    //initialize socket
    this->tcpSocket = new QTcpSocket(this);
    tcpSocket->open(QTcpSocket::ReadWrite);
 
    //connect signals/slots of socket
    QObject::connect(tcpSocket,SIGNAL(connected()),this,SLOT(connected()));
    QObject::connect(tcpSocket,SIGNAL(disconnected()),this,SLOT(disconnected()));
    QObject::connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(readyRead()));
 
 
    this->tcpSocket->setSocketDescriptor(this->socketDescriptor());
    if (this->tcpSocket->waitForReadyRead(kWaitConnectingMillisecond))
        qDebug()<<"New client connected";
    else
        qDebug()<<"Error while connecting client: "+tcpSocket->errorString();
}

Client::Client(const int socketDescriptor,QObject *parent) :
    QObject(parent),
    parent_(parent)
{
    setSocketDescriptor(socketDescriptor);
    //initialize socket
    this->tcpSocket = new QTcpSocket(this);
    tcpSocket->open(QTcpSocket::ReadWrite);

    //connect signals/slots of socket
    QObject::connect(tcpSocket,SIGNAL(connected()),this,SLOT(connected()));
    QObject::connect(tcpSocket,SIGNAL(disconnected()),this,SLOT(disconnected()));
    QObject::connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(readyRead()));


    this->tcpSocket->setSocketDescriptor(this->socketDescriptor());
    if (this->tcpSocket->waitForReadyRead(kWaitConnectingMillisecond))
        qDebug()<<"New client connected";
    else
        qDebug()<<"Error while connecting client: "+tcpSocket->errorString();
}

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printing this tcpSocket->errorString() gives error "The remote host closed the connection".
I even tried to comment out all closing statements that closes socket (for debugging purpose) but didn't do

void Client::readyRead(void)
{
    qDebug()<<"Buffering";
    NetworkObjects::Task *task=new NetworkObjects::Task(parent_,tcpSocket->readAll());
    QObject::connect(task,SIGNAL(taskCompleted()),task,SLOT(deleteLater()));
    task->handleTask();
 
}

void Client::readyRead(void)
{
    qDebug()<<"Buffering";
    NetworkObjects::Task *task=new NetworkObjects::Task(parent_,tcpSocket->readAll());
    QObject::connect(task,SIGNAL(taskCompleted()),task,SLOT(deleteLater()));
    task->handleTask();

}

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see the app instance 1 in above image sends request successfully and app instance 2 receives it fine and creates response

void RequestManager::send(QByteArray *request)
{
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() " + QString(*request) + "  SENDING TO: "+address_+":"+QString::number(port_);
#endif
    sendTcpSocket->abort();
    sendTcpSocket->open(QTcpSocket::ReadWrite);
 
    sendTcpSocket->connectToHost(address_,port_);
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() CONNECTING...";
#endif
 
if (sendTcpSocket->waitForConnected(3000))
{
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() CONNECTED";
#endif
}
 
 
    if (sendTcpSocket->isOpen()==false){
        emit socketCannotOpen();
    }
    else if (sendTcpSocket->isWritable())
    {
 
 
        sendTcpSocket->write(*request);
 
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() SENT!";
#endif
    }
 
   // sendTcpSocket->close();
 
}

void RequestManager::send(QByteArray *request)
{
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() " + QString(*request) + "  SENDING TO: "+address_+":"+QString::number(port_);
#endif
    sendTcpSocket->abort();
    sendTcpSocket->open(QTcpSocket::ReadWrite);

    sendTcpSocket->connectToHost(address_,port_);
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() CONNECTING...";
#endif

if (sendTcpSocket->waitForConnected(3000))
{
#if (DEBUGGING)
    qDebug()<<"RequestManager::send() CONNECTED";
#endif
}


    if (sendTcpSocket->isOpen()==false){
        emit socketCannotOpen();
    }
    else if (sendTcpSocket->isWritable())
    {


        sendTcpSocket->write(*request);

#if (DEBUGGING)
    qDebug()<<"RequestManager::send() SENT!";
#endif
    }

   // sendTcpSocket->close();

}

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can we please try to help me out?

thanks

[naturalpsychic]

no one?

can someone please reply (only if you know the answer)?

[mentalmushroom]

Maybe you should call waitForConnected before calling waitForReadyRead. Also consider non-blocking approach.

[Spitfire]

Attached is simple client-server demo app, see if it works for you and try to resolve your issue based on it.