Qt-interest Archive, April 2007
blocking socket error detection problem
Message 1 in thread
Hi,
I'm trying to use a QTcpSocket in a thread *without* an event loop - so
far everything's been great - I use waitForReadyRead() and
waitForConnected() - whioch allow me to block until the desired event
takes place.
I'm trying to detect if the socket connects properly. I'm connecting
like this:
sock.connectToHost(
cf->getValue("ServerAddress"),
cf->getValue("ServerPort").toInt()
);
(cf) is my own class - basically the IP address and port could be
anything - they're set by the user. I'd like to check whether the socket
has connected properly. So, I do this:
// block until socket is in the connected state:
if (sock.state() != QTcpSocket::ConnectedState)
{
// timeout after 30 seconds:
if (! sock.waitForConnected(30000))
{
// error handling here...
}
}
The problem seems to be that QTcpSocket sets the default state to
ConnectedState, and relies on the user catching the error() signal,
which I can't do since I have no event loop. Even worse, there's no
QAbstractSocket::SocketError entry that indicates the absence of an
error, so I can't check the error manually.
Am I missing something here? How can I check that the socket connected
properly without using an event loop?
Thanks,
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Message 2 in thread
Hi,
> The problem seems to be that QTcpSocket sets the default state to
> ConnectedState, and relies on the user catching the error() signal,
> which I can't do since I have no event loop. Even worse, there's no
> QAbstractSocket::SocketError entry that indicates the absence of an
> error, so I can't check the error manually.
What's the exact problem exactly? What do you see and what do you expect?
The initial state of QTcpSocket does not seem to be ConnectedState:
#include <QApplication>
#include <QTcpSocket>
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
const char host[] = "yyy.trolltech.zzz";
int port = 80;
QTcpSocket socket;
socket.connectToHost(host, port);
if (socket.state() != QTcpSocket::ConnectedState) {
qDebug() << host << "initially not connected";
}
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