Deleting Class causes app crash

In this thread, I created my class and made the arrangements for monitoring it.
How can I delete the class? I can't find a way that will work, myne just crashes the app.

Code:

---

void deleteClass(MyClass *class)
{
       class->disconnect();
      delete class;
}

---

Did you remove your alarm from the map?

QMap<QString, Alarm*> map;
map.remove(name);

Does disconnect work immediately or are there any queued connections (interthread) or posted messages involved?

I need a bigger part of your code to be able to help.

Try to create a minimal working example, that still exhibits the problem!

Johannes

Here's the function that creates instances of my class "Alarm":

Code:

---

Alarm *a = new Alarm(file);
        alarmList.insert(a->objectName(),a);
 
        ADisplay *display = new ADisplay(this);  // other class
 
        connect(a,SIGNAL(soundAlarm(Alarm*)),display,SLOT(showDisplay(Alarm*))); // when its time I call display
 
        connect(display,SIGNAL(quiting()),a,SLOT(quiting()));  // when display is closed call Alarm's quiting() slot (custom) that then:
 
        connect(a,SIGNAL(quiting(Alarm*)),this,SLOT(remActiveAlarm(Alarm*)));  // emit's the quiting() signal passing back to this class the   
                                                                                                                               // object to delete which is:
 
remActiveAlarm(Alarm *a){
       alarmList.remove(a->objectName());
       a->disconnect();
       delete a;
}

---

I can guess 2 things -
One, does remove call destructor too ? Check it, am nto sure.
Second, are you using the Alarm object from where the signal is emitted ? Chances are you are using. So when the code reaches back after the remActiveAlarm() slot, you have a invalid object and hence you get crash.
As a remedy, trying a->deleteLater().

Obviously we still have to guess, how the rest of the code may look like.. We need more. Try to build a small compilable example, that still crashes.

Johannes

Here attached is a small working(crashing) example.

Hi there!

Code:

---

~Alarm()
{
  delete this;
}

---

That is calling the destructor recursively, until a stack overflow happens. The destructor is called, when you delete an object. No reason to delete it again..

Code:

---

~Alarm()
{
}

---

You only delete child objects in the destructor..

Joh

Quote:

---

Originally Posted by aamer4yu

One, does remove call destructor too ? Check it, am nto sure.

---

It does not, because he is using pointers in his collection. Pointers are not automatically deleted.

If you want to properly clear a collection (map, hash, list, ..) of pointers you need to:

Code:

---

qDeleteAll(list);
list.clear();

---

Or one by one, with delete and remove.. as been_1990 is doing..

Johannes

Thanks JohannesMonk. That was the problem.