Hi all,

My problem is as follows: I have an SSL server where multiple clients can connect to. For each client I open a separate thread.

For each request to the database I need to prepare the database as shown in function "authenticateUser" and close the connection once I am finished in order not to overload the database.


The code of the thread is as follows:

Qt Code: 
  1. SslThread::SslThread(int handle, int timeout, QObject *parent) :
  2.     QThread(parent)
  3. {
  4.     m_sockHandle = handle;
  5.     m_connName = QVariant(handle).toString();
  6.     m_connTimeOut = timeout;
  7. }
  8.  
  9. SslThread::~SslThread()
  10. {
  11.     qDebug("Thread Destructor");
  12.     qDebug()<<"socket = "<< m_connName;
  13.     QSqlDatabase::removeDatabase(m_connName);
  14. }
  15.  
  16. void SslThread::run()
  17. {
  18.     QSslSocket  socket;
  19.     m_rxTx = new RxTx(&socket);
  20.  
  21.     if (!socket.setSocketDescriptor(m_sockHandle))
  22.     {
  23.         qDebug()<<tr("Descriptor failed with %1").arg(socket.errorString());
  24.         return;
  25.     }
  26.     socket.setPrivateKey(":/Certificates/mycert_key.pem");
  27.     socket.setLocalCertificate(":/Certificates/mycert.pem");
  28.  
  29.     QFile f(":/Certificates/cacert.pem");
  30.     f.open(QIODevice::ReadOnly);
  31.     QSslCertificate cert(f.readAll());
  32.     if (!cert.isValid())
  33.         qDebug("Invalid Certificate");
  34.     else
  35.         socket.addCaCertificate(cert);
  36.  
  37.     connect(&socket, SIGNAL(disconnected()), this, SLOT(killThread()));
  38.     connect(m_rxTx, SIGNAL(packetReceived(QByteArray)), this, SLOT(handleIncomingMessage(QByteArray)));
  39.  
  40.     QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL", m_connName);
  41.     if (!db.isValid())
  42.     {
  43.         qCritical() << tr("Could not open the database QMYSQL:%1").arg(m_connName);
  44.         return;
  45.     }
  46.  
  47.     db.setDatabaseName("testDB");
  48.     db.setHostName("localhost");
  49.     db.setPort(3306);
  50.  
  51.     if (!db.open("dbUser", "dbPass"))
  52.     {
  53.         qDebug()<<"OpenDB Error:" << db.lastError().text();
  54.         return;
  55.     }
  56.     db.close();
  57.     socket.startServerEncryption();
  58.     //errTimer.setInterval(m_connTimeOut);
  59.     //connect(&errTimer, SIGNAL(timeout()), this, SLOT(killThread()));
  60.     //errTimer.start();
  61.     exec();
  62.     qDebug("Just after exec...");
  63. }
  64.  
  65. void SslThread::killThread()
  66. {
  67.     quit();
  68. }
  69.  
  70. void SslThread::handleIncomingMessage(QByteArray ba)
  71. {
  72.     QDataStream ds(&ba, QIODevice::ReadOnly);
  73.     quint32 command;
  74.     ds >> command;
  75.     switch (command)
  76.     {
  77.     case PROT_LOGIN:
  78.         {
  79.             QString user;
  80.             QString pass;
  81.             ds >> user;
  82.             ds >> pass;
  83.             authenticateUser(user, pass);
  84.         }
  85.         break;
  86.     default:
  87.         qWarning() << tr("Unknown command %1 from client").arg(command);
  88.         break;
  89.     }
  90. }
  91.  
  92. void SslThread::authenticateUser(QString userName, QString password)
  93. {
  94.     QSqlDatabase db = QSqlDatabase::database(m_connName, false);
  95.     db.setDatabaseName("testDB");
  96.     db.setHostName("localhost");
  97.     db.setPort(3306);
  98.     if (!db.isValid())
  99.     {
  100.         qWarning() << tr("The database is not vaild");
  101.         return;
  102.     }
  103.     if (!db.open("dbUser", "dbPass"))
  104.     {
  105.         qWarning() << tr("Could not open the database");
  106.         return;
  107.     }
  108.     QSqlQuery query(db);
  109.     query.exec("Do something...");
  110.     ....
  111.     db.close();
  112. }
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My first question: If I have many functions like "authenticateUser" which need to access the database, how do I prepare a single instance of the database connection and set up a query and use it immediately instead of setting database parameters each time?

My second question: If I commit the following section in the "run" function:
Qt Code: 
  1. #if 0
  2.     if (!db.open("dbUser", "dbPass"))
  3.     {
  4.         qDebug()<<"OpenDB Error:" << db.lastError().text();
  5.         return;
  6.     }
  7. #endif
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and the connection is dropped (by client or by closing the sever), I get the following error:
"Error in my_thread_global_end(): 1 threads didn't exit"
It's like I need to open the connection for the first time in order to use it later by "QSqlDatabase::database(m_connName, false)" function.


I really need help on this one.

Thanks in advance.