QTcpSocket connection problem

[valdemar593]

gdb

#0  0x00402b73 in QMetaObject::invokeMethod (obj=0x7e9ff4, 
    member=0x22a33f "connectToHostImplementation", type=Qt::DirectConnection, 
    ret=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., 
    val7=..., val8=..., val9=...)
    at /var/tmp/qt-src/src/corelib/kernel/qmetaobject.cpp:1135
#1  0x001efe73 in invokeMethod (this=0x7e9ff4, hostName=..., port=6178, openMode=...)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs.h:408
#2  QAbstractSocket::connectToHost (this=0x7e9ff4, hostName=..., port=6178, 
    openMode=...) at /var/tmp/qt-src/src/network/socket/qabstractsocket.cpp:1304
#3  0x001f1835 in QAbstractSocket::connectToHost (this=0x7e9ff4, address=..., 
    port=6178, openMode=...)
    at /var/tmp/qt-src/src/network/socket/qabstractsocket.cpp:1417
#4  0x080494e4 in Client::establishConnection (this=0xbffff1fc)
    at ../NetTestClient/client.cpp:13
#5  0x08049201 in main (argc=1, argv=0xbffff2d4) at ../NetTestClient/main.cpp:8

#0  0x00402b73 in QMetaObject::invokeMethod (obj=0x7e9ff4, 
    member=0x22a33f "connectToHostImplementation", type=Qt::DirectConnection, 
    ret=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., 
    val7=..., val8=..., val9=...)
    at /var/tmp/qt-src/src/corelib/kernel/qmetaobject.cpp:1135
#1  0x001efe73 in invokeMethod (this=0x7e9ff4, hostName=..., port=6178, openMode=...)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs.h:408
#2  QAbstractSocket::connectToHost (this=0x7e9ff4, hostName=..., port=6178, 
    openMode=...) at /var/tmp/qt-src/src/network/socket/qabstractsocket.cpp:1304
#3  0x001f1835 in QAbstractSocket::connectToHost (this=0x7e9ff4, address=..., 
    port=6178, openMode=...)
    at /var/tmp/qt-src/src/network/socket/qabstractsocket.cpp:1417
#4  0x080494e4 in Client::establishConnection (this=0xbffff1fc)
    at ../NetTestClient/client.cpp:13
#5  0x08049201 in main (argc=1, argv=0xbffff2d4) at ../NetTestClient/main.cpp:8

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qt creator

0 QHashData::detach_helper2 qhash.cpp 206 0x001a18fa
1 QHash<QObject*, QHash<QEvent::Type, int> >::detach_helper qhash.h 582 0x002e69eb
2 detach qhash.h 299 0x002dbc23
3 operator[] qhash.h 737 0x002dbc23
4 QStateMachinePrivate::registerEventTransition qstatemachine.cpp 1598 0x002dbc23
5 invokeMethod qobjectdefs.h 408 0x00a25e73
6 QAbstractSocket::connectToHost qabstractsocket.cpp 1304 0x00a25e73
7 QAbstractSocket::connectToHost qabstractsocket.cpp 1417 0x00a27835
8 Client::establishConnection client.cpp 13 0x080494e4
9 main main.cpp 8 0x08049201

[wysota]

What does the main() function look like?

[valdemar593]

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    Client client;
    client.establishConnection();
    return a.exec();
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    Client client;
    client.establishConnection();
    return a.exec();
}

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[wysota]

Ah.... I missed it. You are creating a local variable called "clientSocket" in your constructor that shadows the class member called "clientSocket" thus it remains uninitialized and a dangling pointer causes a crash.

[valdemar593]

Oh my god =))
Thanks a lot man!
But what about the first example? Everything seems to be correct there, but the socket stays in connecting state all the time while the server emits newConnection()?

[wysota]

I don't know, I'd need to see code that's more complete than this.