QTcpSocket/QTcpServer on a heavy load server

Eumcoz

Hello, I am designing and making a server that should be able to handle about 100+ hits per second. The information I am getting from the server is just the HTTP header. Based on the information from the header, it will query a database(different thread) for some information and send the final information back to the QTcpServer which create an output string, and send back a HTTP Response. I am having a big problem with this that I cannot debug. My code look similar to this:

@TCPInterface::TCPInterface(QObject *parent): QTcpServer(parent)
{
//start listening for tcp traffic on port 80
listen(QHostAddress::Any, 80);

connect(this,SIGNAL(sendInfo(QTcpSocket*, QString *)), databaseThread, SLOT(recieveInfo(QTcpSocket*, QString*)));
connect(databaseThread, SIGNAL(sendToTCPSend(QTcpSocket *, QString *)), this, SLOT(TCPSend(QTcpSocket*, QString*)));

}@

@void TCPInterface::incomingConnection(int socket)
{
QTcpSocket *s = new QTcpSocket(this);

connect(s, SIGNAL(readyRead()), this, SLOT(readClient()));

// connect(s, SIGNAL(disconnected()), this, SLOT(discardClient()));

s->setSocketDescriptor(socket);

}@

@//void TCPInterface::discardClient()
//{
// QTcpSocket* socket = (QTcpSocket*)sender();
// socket->deleteLater();
//}@

@void TCPInterface::readClient()
{
QTcpSocket* socket = (QTcpSocket*)sender();

QString header;
while(socket->canReadLine())
{
    header += socket->readLine();
}

emit sendInfo(socket, headerInfo);

}@

@void databaseThread::recieveInfo(QTcpSocket* socket, QString* headerInfo)
{
QString*outputInfo = getDatabaseInfo(headerInfo);
emit sendToTCPSend(socket, outputInfo);
}@

@void TCPInterface::TCPSend(QTcpSocket* socket, QString* outputInfo);
{
QString response = "HTTP/1.0 200 Ok\r\n";
response += "Content-Type: text/html; charset="utf-8"\r\n";
response += "\r\n" + *outputInfo + "\n";

if(socket->isWritable() && socket->isOpen())
{
     socket->write(response.toAscii());
}
//socket->disconnectFromHost();
socket->close();
delete headerInfo;

}@

I having one main problem which I have an idea what it is, but cannot find a solution to fix it.

My problem is my memory is constantly increasing as I get more hits. I am sure the cause of this is my QTcpSockets are never being deleted, since I am just closing them. However when I don't use close, and use disconnectFromHost and disconnected/discardClient slot/signal my server will crash with heavy traffic(no message or anything so I am not sure of the exact reason of the crash). Has anyone run into this problem before? Any ideas at all.

franku

Why not change:
@
...}
//socket->disconnectFromHost();
socket->close();
delete headerInfo;
}@

into:

@
...}
//socket->disconnectFromHost();
socket->close();
delete socket;
delete headerInfo;
}@

franku

You'll have to find a way to delete this socket:

@
void TCPInterface::incomingConnection(int socket)
{
QTcpSocket *s = new QTcpSocket(this);
...
@