QT C++ - Class problem wait until signal is processed and return data back

I've this code here in a program I'm making but I've a problem, How can I keep the program waiting for data on http2 before returning to the tcpserver class? And how can I get the data in the tcpserver class?

This is like a checkpoint were I need to get the data from the server and then keep running the tcpserver and use that data there.

tcpserver.cpp

#include "tcpserver.h"
#include "protocol.h"
#include "http2.h"

QTextStream in(stdin);

tcpserver::tcpserver(QObject *parent) :
    QObject(parent)
{
    server = new QTcpServer(this);

    [ ... Other Server Stuff ... ]

    http2 *h = new http2(this); 

}

I've tried this with no luck:

http2.cpp

#include "http2.h"
bool httpdonne = false;
QByteArray finaldata;

http2::http2(QObject *parent, QByteArray url, QByteArray data) :
    QObject(parent)
{
    url.append(data);

    m_manager = new QNetworkAccessManager(this);
    connect(m_manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(httpdown(QNetworkReply*)));

    QNetworkRequest request;
    request.setUrl(QUrl(url));
    request.setRawHeader("User-Agent", "My开发者_如何学GoOwnBrowser 1.0");

    m_manager->get(request);

    while ( httpdonne == false ) {

    }

    finaldata.append("HTTP: ");
    qDebug() << finaldata;

}

QByteArray http2::httpdown(QNetworkReply* result)
{
    QByteArray data = result->readAll();
    finaldata = data;
    httpdonne = true;
    return data;
}

Thanks a lot! ;)

---

Qt makes use of signals and slots and the event loop. If you have no QEventLoop running which is normally provided by QApplication your events will not be handled.

Take a peek at this question to see how to create an event loop to simulate a blocking (synchronous) using the asynchronous programming model.

In addition I normally add a QTimer too:

QEventLoop loop;
..
QTimer timer;
timer.setInterval(2000);
timer.setSingleShot(true);
loop.connect(&timer, SIGNAL(timeout()), SLOT(handleTimeout()));
timer.start();
..
//Setup your objects / connections here...
..
loop.exec(); //Your signals and slots will be triggered / handled now!

---

Qt network classes are all signal-driven. That is, you create functions which handle various events (data ready etc) and connect them to the appropriate slots. Blocking isn't really the way they are to be used.

---

Of course I would never recommend what you are trying to achieve but if you still wanna "shoot yourself in the foot" :) then here's what you can try,

run the manager as a separate thread and make the http2 or tcpserver thread wait on a condition variable. And when the manager is done invoke the threads waiting the the condition variable.

---

You can use my WaitForSignalHelper class posted here , it does what you want: wait for a timeout OR signal to be emitted...