Sample for Mutithreading

[HugoHiasl]

Hmm.... thanks for this really interesting approach. I will do some tests with a single thread environment.

Actually I stuck in another problem. As mentioned earlier I'm really familiar with C# and Java. But I'm completely new to QT. I plan to create a BaseClass for the handlers for different manufacturers.

I planned to make a base class that defines the set of methods that will be called by the serial thread. First I tried to make an Interface but I didn't manage it The implementation classes shall emit Signals to be able to connect them to the database thread.

Now I'm trying it with a BaseClass which I want to subclass. But even with my 10 line trial I stuck in linker warnings.

This is the implmentation now:

serialhandlerbase.h

#ifndef SERIALHANDLERBASE_H
#define SERIALHANDLERBASE_H
 
#include <QObject>
 
class SerialHandlerBase : public QObject
{
    Q_OBJECT
public:
    SerialHandlerBase();
    virtual void startHandling();
    virtual void stopHandling();
};
 
#endif // SERIALHANDLERBASE_H

#ifndef SERIALHANDLERBASE_H
#define SERIALHANDLERBASE_H

#include <QObject>

class SerialHandlerBase : public QObject
{
    Q_OBJECT
public:
    SerialHandlerBase();
    virtual void startHandling();
    virtual void stopHandling();
};

#endif // SERIALHANDLERBASE_H

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serialbasehandler.cpp

#include "serialhandlerbase.h"
 
SerialHandlerBase::SerialHandlerBase()
{
}

#include "serialhandlerbase.h"

SerialHandlerBase::SerialHandlerBase()
{
}

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The compiler says: undefined reference to 'vtable for SerialHandlerBase'
and the linker: collect2: Id returned 1 exit status

I can get rid of the compiler messages if I declare a destructor and implement it in the cpp file. But it does not fix the linker message.

Do you have an idea for me?