The program has unexpectedly finished.

Rajashekara_NR

#ifndef AMBIENTLIGHT_H
#define AMBIENTLIGHT_H
#include <QDebug>
#include "serviceproxy.h"
class Ambientlight
{
public:
Ambientlight(Serviceproxy *serviceprxy = new Serviceproxy);
~Ambientlight();
private:
Serviceproxy *serviceprxy;
};

#endif // AMBIENTLIGHT_H
#include "ambientlight.h"

Ambientlight::Ambientlight(Serviceproxy *serviceprxy)
{
qDebug() << Q_FUNC_INFO;
}

Ambientlight::~Ambientlight()
{
delete serviceprxy;
qDebug() << Q_FUNC_INFO;
}
#ifndef SERVICEPROXY_H
#define SERVICEPROXY_H
#include <QDebug>

class Serviceproxy
{
public:
Serviceproxy();
~Serviceproxy();
};

#endif // SERVICEPROXY_H
#include "serviceproxy.h"

Serviceproxy::Serviceproxy()
{
qDebug() << Q_FUNC_INFO;
}

Serviceproxy::~Serviceproxy()
{
qDebug() << Q_FUNC_INFO;
}

#include "widget.h"

#include <QApplication>
#include "ambientlight.h"
#include "serviceproxy.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget w;
Ambientlight Al;
Serviceproxy *serprxy = new Serviceproxy;
Ambientlight AL2(serprxy);
w.show();
return a.exec();
}

output:
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(Serviceproxy*)
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(Serviceproxy*)
Serviceproxy::~Serviceproxy()
03:25:05: The program has unexpectedly finished.

My question how to delete the serviceproxy object created in main.

jsulm

@Rajashekara_NR First thing to do in such a situation is running through debugger.
So, please do so and post the stack trace after crash here.

Also, why do you allocate Serviceproxy on the heap?

Rajashekara_NR

@jsulm,
My requirement is In AmbientLight i had created a heap object of serviceProxy and deleted in destructor. If someone had created an object of Ambientlight and they will pass Serviceproxy object then how to delete the serviceproxy object.

JonB

@Rajashekara_NR
I don't really understand what you are saying here, but @jsulm is saying it's simpler not to have to delete the object if instead you use:

Serviceproxy serprxy;
Ambientlight AL2(&serprxy);

and serviceprxy no longer needs to be a class member variable.

Rajashekara_NR

Hi @JonB,

You are right if we create in stack and passing is fine. But still my program is crashing.

Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(Serviceproxy*)
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(Serviceproxy*)
Ambientlight::~Ambientlight()
Serviceproxy::~Serviceproxy()
Serviceproxy::~Serviceproxy()
04:30:41: The program has unexpectedly finished.

JonB

@Rajashekara_NR

@jsulm said in The program has unexpectedly finished.:

@Rajashekara_NR First thing to do in such a situation is running through debugger.
So, please do so and post the stack trace after crash here.

J.Hilk

you never pass serviceprxy to the class pointer

Ambientlight::Ambientlight(Serviceproxy *serviceprxy) //passing on missing
{
     qDebug() << Q_FUNC_INFO;
}

Ambientlight::~Ambientlight()
{
      delete serviceprxy;
      qDebug() << Q_FUNC_INFO;
}

so you call delete on a pointer pointing to some random memory address.

Looks like thats your problem.

Always initialise your variables! a nullptr would work just fine

private:
    Serviceproxy *serviceprxy{nullptr};

or better, since you have a default heap allocation in the constructor anyway pass it on.

Ambientlight::Ambientlight(Serviceproxy *serviceprxy) : serviceprxy(serviceprxy)
{
    qDebug() << Q_FUNC_INFO;
}

btw please rename your member class pointer this is highly confusing.

Rajashekara_NR

@J-Hilk
class Ambientlight
{
public:
Ambientlight(const QPointer<Serviceproxy> &serviceProxies = new Serviceproxy());
~Ambientlight();
void test();
private:
QPointer<Serviceproxy> m_serviceprxy;

};
Ambientlight::Ambientlight(const QPointer<Serviceproxy> &serviceProxies):m_serviceprxy(serviceProxies)
{
qDebug() << Q_FUNC_INFO;
}

Ambientlight::~Ambientlight()
{
//if(m_serviceprxy!= nullptr)
qDebug() << Q_FUNC_INFO ;
delete m_serviceprxy;
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget w;
// Serviceproxy *serprxy = new Serviceproxy;
// Ambientlight Al(serprxy);
// Serviceproxy *serprxy2 = new Serviceproxy;
// Ambientlight AL2(serprxy2);
// Serviceproxy *serprxy3 = new Serviceproxy;
// Ambientlight AL3(serprxy3);
Serviceproxy serprxy;
Ambientlight Al(&serprxy);
Serviceproxy serprxy2;
Ambientlight AL2(&serprxy2);

// delete serprxy;
// delete serprxy2;
// delete serprxy3;
// serprxy->test();
// serprxy2->test();
// serprxy3->test();
w.show();
return a.exec();
}
output:
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(const QPointer<Serviceproxy>&) QObject(0x7ffd1fb752d0)
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(const QPointer<Serviceproxy>&) QObject(0x7ffd1fb752f0)
Ambientlight::~Ambientlight() QObject(0x7ffd1fb752f0)
virtual Serviceproxy::~Serviceproxy()
double free or corruption (out)
07:47:46: The program has unexpectedly finished.
Note: If i use Stack object i got crash.

output: If i use Serprxy as heap object.
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(const QPointer<Serviceproxy>&)
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(const QPointer<Serviceproxy>&)
Serviceproxy::Serviceproxy()
Ambientlight::Ambientlight(const QPointer<Serviceproxy>&)
virtual Serviceproxy::~Serviceproxy()
virtual Serviceproxy::~Serviceproxy()
virtual Serviceproxy::~Serviceproxy()
void Serviceproxy::test()
void Serviceproxy::test()
void Serviceproxy::test()

one quick update if you want i will run through debugger mode.

J.Hilk

@Rajashekara_NR

Note: If i use Stack object i got crash.

yes of course, you manually delete a stack allocated object, what else did you expect?

JonB

@JonB said in The program has unexpectedly finished.:

but @jsulm is saying it's simpler not to have to delete the object if instead you use:
Serviceproxy serprxy;
Ambientlight AL2(&serprxy);

@Rajashekara_NR
[My bold now.] If you change to stack object you (must) no longer delete it....

Rajashekara_NR

@J-Hilk ,
No i am not deleting stack object.
Actually i am deleting dynamically allocated object.

J.Hilk

@Rajashekara_NR said in The program has unexpectedly finished.:

No i am not deleting stack object.

Serviceproxy serprxy;
Ambientlight Al(&serprxy);
...
Ambientlight::Ambientlight(const QPointer<Serviceproxy> &serviceProxies):m_serviceprxy(serviceProxies)
{
qDebug() << Q_FUNC_INFO;
}

Ambientlight::~Ambientlight()
{
//if(m_serviceprxy!= nullptr)
qDebug() << Q_FUNC_INFO ;
delete m_serviceprxy;
}

you're clearly deleting a stack allocated object by hand,

this is c++ you can shoot yourself in the food, and you did!

Rajashekara_NR

@J-Hilk ,

one quick question here:
Ambientlight::~Ambientlight()
{
//if(m_serviceprxy!= nullptr)
qDebug() << Q_FUNC_INFO ;
delete m_serviceprxy;
}

Is there a way to handle m_serviceprxy in destructor. Please let me know. It should work for both stack and heap objects.

jsulm

@Rajashekara_NR said in The program has unexpectedly finished.:

Is there a way to handle m_serviceprxy in destructor

What do you want to "handle" in the destructor?
There is no need to delete it in destructor.

JonB

@JonB said in The program has unexpectedly finished.:

@Rajashekara_NR
I don't really understand what you are saying here, but @jsulm is saying it's simpler not to have to delete the object if instead you use:
Serviceproxy serprxy;
Ambientlight AL2(&serprxy);

and serviceprxy no longer needs to be a class member variable.

I feel the OP is not reading anything here:

Stack variable => no delete
Using this code => no member variable.

Rajashekara_NR

@jsulm ,
Actually i had a task like earlier m_serviceprxy use normal with out Qpointers. Now i had done all the changes with Qpointer need to delete the m_serviceprxy in destructor. Becuase heap object is there in the AmbientLight constructor. We not restricting the AmbientLight object creation with serviceproxies like stack or heap. so ultimately we should delete m_serviceprxy should be there in ambienltLight destructor. It should work for both the use cases like this:

Serviceproxy *serprxy = new Serviceproxy;
Ambientlight Al(serprxy);
Serviceproxy serprxy;
Ambientlight Al(&serprxy);

JonB

@Rajashekara_NR
The same code in the destructor cannot handle both those cases. You can delete if something was newed, not otherwise. You cannot delete if it might be a stack variable.

Either stipulate in your "contract" that Ambientlight requires a newed Serviceproxy which it then takes ownership of and deletes, or require the caller/outside world to deal with the Serviceproxy's lifetime.

Or do it with QObject parentage.