delay in qapplication

[mandal]

I am using Visual Studio 2003 and qt 4.2.0.I am using a dll that written to access MSSQL Server database with qt libraries.

Executable of the project runs properly on my pc. It exeutes a stored procedure and retrieves the results in a few seconds.
But when i try it on another pc it takes 40 seconds to retrieve the database records(by executing the same stored proceudre.).

I debugged the project and realized taht it is the
QApplication a(argc, argv);
line that takes the approximately 40 seconds.

Anybody has any idea which setting causes that delay?

[wysota]

You'd have to debug more properly. Maybe the driver initialisation takes so long?

[mandal]

Here is my code.

#include "dbclientside.h"
#include <QApplication>
void execute()
{
    //calls methods of dll to execute a stored procedure and retrieve the resultset
   //prints the resultset to stdout
}
int main(int argc, char* argv[])
{
    QApplication a(argc, argv); //This line takes approximately 40 seconds.
 
    execute(); //This line takes just 1 or 2 seconds.
 
    return a.exec();
}

#include "dbclientside.h"
#include <QApplication>
void execute()
{
    //calls methods of dll to execute a stored procedure and retrieve the resultset
   //prints the resultset to stdout
}
int main(int argc, char* argv[])
{
    QApplication a(argc, argv); //This line takes approximately 40 seconds.

    execute(); //This line takes just 1 or 2 seconds.

    return a.exec();
}

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If you mean QODBC driver, it is initialized in execute() method. And does not take so much time.

[jpn]

Could you insert a breakpoint on the line constructing a QApplication object and then step into QApplication's constructor while debugging? Maybe it's something in QCoreApplication::init() what's taking so long.

[wysota]

If you mean QODBC driver, it is initialized in execute() method. And does not take so much time.

Plugins get initialised inside QCoreApplication constructor. I didn't mean your code to initialise the database.

Do what JPN suggests - dive into QApplication code. Remember to compile in debug mode or else you won't get much info.

[mandal]

void QApplicationPrivate::construct(
#ifdef Q_WS_X11
   Display *dpy, Qt::HANDLE visual, Qt::HANDLE cmap
#endif
                                                           )
{
    Q_INIT_RESOURCE(qstyle);
 
    qt_is_gui_used = (qt_appType != QApplication::Tty);
    process_cmdline();  //<---- HERE WHERE MY CODE HANGS FOR 40 SECONDS
    // Must be called before initialize()
    qt_init(this, qt_appType
#ifdef Q_WS_X11
            , dpy, visual, cmap
#endif
            );
    initialize();
    eventDispatcher->startingUp();
 
#ifdef QT_EVAL
    extern void qt_gui_eval_init(uint);
    qt_gui_eval_init(application_type);
#endif
}

void QApplicationPrivate::construct(
#ifdef Q_WS_X11
   Display *dpy, Qt::HANDLE visual, Qt::HANDLE cmap
#endif
                                                           )
{
    Q_INIT_RESOURCE(qstyle);

    qt_is_gui_used = (qt_appType != QApplication::Tty);
    process_cmdline();  //<---- HERE WHERE MY CODE HANGS FOR 40 SECONDS
    // Must be called before initialize()
    qt_init(this, qt_appType
#ifdef Q_WS_X11
            , dpy, visual, cmap
#endif
            );
    initialize();
    eventDispatcher->startingUp();

#ifdef QT_EVAL
    extern void qt_gui_eval_init(uint);
    qt_gui_eval_init(application_type);
#endif
}

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I debugged detailly and found the line causes the delay.This method is in qapplcation.cpp file.
Any suggestions? Thanx a lot