QNetworkAccessManager asynchronous API

[leonidwang]

As Qt document says:

@
QNetworkAccessManager manager = new QNetworkAccessManager(this);
connect(manager, SIGNAL(finished(QNetworkReply)),
this, SLOT(replyFinished(QNetworkReply*)));

manager->get(QNetworkRequest(QUrl("http://qt.nokia.com")));
@

bq. QNetworkAccessManager has an asynchronous API. When the replyFinished slot above is called, the parameter it takes is the QNetworkReply object containing the downloaded data as well as meta-data (headers, etc.).

I'm a little curious about the implementation of this asynchronous API.
Of course, Qt source code will give me the answer, but it's more convenience to get some basic explanation here :)

[dangelog]

What do you mean exactly? QNAM is built on top of QTcpSocket, which in turn has its async API (readyRead(), disconnected(), error(), etc. signals). So it's something like

QTcpSocket emits a signal -> some slot we don't know -> (read and process the data) -> emit QNetworkReply / QNetworkAccessManager signals.

The QTcpSocket async is built on top of an ordinary select(2). I briefly talked about this in this wiki page: http://developer.qt.nokia.com/wiki/Threads_Events_QObjects .

[leonidwang]

You answer is pretty clear, thanks.

So, it's based on select(2) sys call.
I just want to make sure. The link is very informative.