Threading issue in DLL

[CristonDK]

Hi,

I have a low level HW communication interface, which I would like to embed into a DLL.

I create and starts a QThread, and in this tread's run loop, I create a simple handler object which I start with a QTimer:singleShot

My problem:

Everything works, as long I run the the Application from QtCreator (either in Debug or Release mode - both works)

But when I build a static release version, the eventloop seems to stop or never start.

I have build a very basic solution, for anyone to inspect.

Please advice - Thanks

[wysota]

Static build will probably not allow you to load a dynamic library.

[CristonDK]

Hi,

The DLL is loaded alright, I'm able to call functions getConst and getCounter in IBHandler, when it is loaded.

But the mainloop in IBHandler is not running.

#include "ibkernel.h"
 
IBKernel::IBKernel(QObject *parent) :
    QThread(parent)
{
}
 
IBKernel::~IBKernel()
{
 
}
 
IBHandler* IBKernel::getHandler()
{
    return handler;
}
 
void IBKernel::startKernel()
{
    exec();
}
 
void IBKernel::stopKernel()
{
    quit();
}
 
void IBKernel::run()
{
    handler = new IBHandler();
    //handler->moveToThread(this);
    QTimer::singleShot(10, handler, SLOT(MainLoop()));
 
    exec();
 
    delete handler;
    handler = 0;
}

#include "ibkernel.h"

IBKernel::IBKernel(QObject *parent) :
    QThread(parent)
{
}

IBKernel::~IBKernel()
{

}

IBHandler* IBKernel::getHandler()
{
    return handler;
}

void IBKernel::startKernel()
{
    exec();
}

void IBKernel::stopKernel()
{
    quit();
}

void IBKernel::run()
{
    handler = new IBHandler();
    //handler->moveToThread(this);
    QTimer::singleShot(10, handler, SLOT(MainLoop()));

    exec();

    delete handler;
    handler = 0;
}

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#include "ibhandler.h"
 
IBHandler::IBHandler(QObject *parent) :
    QObject(parent)
{
    mainLoopCnt = 30;
}
 
IBHandler::~IBHandler()
{
 
}
 
int IBHandler::getCounter()
{
    return mainLoopCnt;
}
 
int IBHandler::getConst()
{
    return 99;
}
 
void IBHandler::MainLoop()
{
    // THIS STOPS or NEVER STARTS in the static released version
 
    mainLoopCnt++;
 
    QTimer::singleShot(0, this, SLOT(MainLoop()));
}

#include "ibhandler.h"

IBHandler::IBHandler(QObject *parent) :
    QObject(parent)
{
    mainLoopCnt = 30;
}

IBHandler::~IBHandler()
{

}

int IBHandler::getCounter()
{
    return mainLoopCnt;
}

int IBHandler::getConst()
{
    return 99;
}

void IBHandler::MainLoop()
{
    // THIS STOPS or NEVER STARTS in the static released version

    mainLoopCnt++;

    QTimer::singleShot(0, this, SLOT(MainLoop()));
}

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[amleto]

have you statically built qt libraries as well?

[CristonDK]

Hi,

Yep! - All libs statically build. And used to build both the TestLibTest application and the DLL

[CristonDK]

Problem found!

In standalone mode the DLL seems to need a QCoreApplication for the QTimer to work

Thanks anyway

[wysota]

In any configuration QCoreApplication is needed for timers to work.