QTcpSocket and QThread

[Sasha]

Hi,i am learing qt programing and i trying to make basic chat server with QThread and QTcpServer.
I have this error:
QObject: Cannot create children for a parent that is in different thread.
(Parent is QNativeSocketEngine(0x3b77c8), parent's thread is myThread(0xa0df70), current thread is QThread(0x3b2d38).

My code is :
chatserver.cpp:

#include "chatserver.h"



chatServer::chatServer(QObject *parent)
{
    hash=new QHash<qintptr,myThread*>;
    h_nicks=new QHash<qint32,QString>;
    //connect(client,SIGNAL(sendMessage(QByteArray)),this,SLOT(allSendMessage(QByteArray)),Qt::AutoConnection);
}

void chatServer::startServer()
{
    if(this->listen(QHostAddress::Any,1213)){
        qDebug()<<"Server started";
    }else{
        qDebug()<<"Server could not be started";
    }
}

void chatServer::incomingConnection(qintptr handle)
{
    qDebug()<<"Incoming connection "<<handle;
    client=new myThread(handle,h_nicks,this);
    hash->insert(handle,client);
    connect(client,SIGNAL(finished()),client,SLOT(deleteLater()));
    connect(client,SIGNAL(sendMessage(QByteArray)),this,SLOT(allSendMessage(QByteArray)),Qt::AutoConnection);
    client->start();
}

void chatServer::allSendMessage(QByteArray array)
{
    qDebug()<<"Test!!!!";
    foreach (qintptr i, hash->keys()) {
        hash->value(i)->getMessage(array);
    }
}

chatserver.h:

#ifndef CHATSERVER_H
#define CHATSERVER_H

#include <QObject>
#include <QTcpServer>
#include "mythread.h"
#include <QHash>


class chatServer : public QTcpServer
{
    Q_OBJECT
public:
    explicit chatServer(QObject *parent = 0);
    void startServer();
protected:
    void incomingConnection(qintptr handle);
public slots:
    void allSendMessage(QByteArray array);
private:
    QHash<qintptr,myThread*> *hash;
    myThread *client;
    QHash<qint32,QString> *h_nicks;
};

#endif // CHATSERVER_H

mythread.cpp:

#include "mythread.h"


myThread::myThread(qintptr id,QHash<qint32,QString> *hnick, QObject *parent)
{
    this->socketDescriptor=id;
    h_nicks=hnick;



}

void myThread::run()
{
    qDebug()<<"Starting threadh_nick id "<<this->socketDescriptor;
    socket=new QTcpSocket;
    qDebug()<<"1";
    if(!socket->setSocketDescriptor(this->socketDescriptor)){
        qDebug()<<socket->error();
        return;
    }

    connect(socket,SIGNAL(readyRead()),this,SLOT(readyRead()),Qt::DirectConnection);
    connect(socket,SIGNAL(disconnected()),this,SLOT(disconnected()),Qt::DirectConnection);

    qDebug()<<"Client connect to "<<this->socketDescriptor;

    exec();
}

void myThread::getMessage(QByteArray array)
{
    qDebug()<<array;
    //socket->write(array);
    //socket->waitForReadyRead();
    this->socket->write(array);

}

void myThread::readyRead()
{
    qint32 messageType;
    QByteArray in=socket->readAll();
    QDataStream in_d(&in,QIODevice::ReadOnly);
    in_d>>messageType;
    qDebug()<<messageType;
    if(messageType==2){
        in_d>>nick;
        qDebug()<<nick;
        h_nicks->insert(this->socketDescriptor,nick);
    }else{
    QByteArray array;//=socket->readAll();
    QDataStream buffer(&array,QIODevice::ReadWrite);
    qint32 messageSender;
    messageSender=this->socketDescriptor;
    buffer<<messageSender;
    QString readSocket;
    in_d>>readSocket;
    buffer<<readSocket;
    qDebug()<<this->socketDescriptor<<" "<<array;
    emit sendMessage(array);
    }
}

void myThread::disconnected()
{

    socket->deleteLater();
    exit(0);
}

mythread.h :

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QObject>
#include <QTcpSocket>
#include <QThread>
#include <QDebug>
#include <QAbstractSocket>
#include <QDataStream>
#include <QString>

class myThread : public QThread
{
    Q_OBJECT
public:
   explicit myThread(qintptr id,QHash<qint32,QString> *hnick,QObject *parent=0);
    void run();
    void getMessage(QByteArray array);
private:
    QTcpSocket *socket;
    qintptr socketDescriptor;
    QString nick;
    QHash<qint32,QString> *h_nicks;
public slots:
    void readyRead();
    void disconnected();
signals:
    void sendMessage(QByteArray array);
};

#endif // MYTHREAD_H

Can someone explain me how is right way to do multi thread socket programming?
Thanks for help.

[edit: added missing coding tags ``` SGaist]

[SGaist]

Hi,

One thing I can see is that you don't call the base class constructor in any of your sub-classes.

Note that if you are beginning programming, dealing with threads first for might not be the best idea

[Sasha]

Hi, thanks for advice, i change my application server, so i dont use threads.
Now what is proper way to close socket.
In incomingconnections i have QHash and i insert socketdescriptor as key in that hash and socket pointer as value.
Then i connect socket readyRead and disconnected signals with my slots.
But in disconnected slot i have this code:
QTcpSocket m_socket=static_cast<QTcpSocket>(sender());
and when i put this qDebug()<<m_socket->socketDescriptor() i got result -1.
Because i got result -1 i cant delete socket from my QHash?
Where i make mistake?
Btw code from above works in slot readyRead.

Thanks for help.
[edit]
Sorry, but i found what is my problem. I was using socketDescriptor as key in hash but i should use QTcpSocket as keys in QHash.

[SGaist]

You should also use qobject_cast rather than static_cast, static cast doesn't do any check so you might be casting to something invalid.