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Re: Core chat... [message #12395 is a reply to message #12392]

Sat, 27 October 2007 15:21

mdelfede
Messages: 1308
Registered: September 2007

Ultimate Contributor

I did ask the former question because I was lookin' inside MainWindow code.... Looking for the OpenGL bug.
But then I realized that Ctrl::Add() is quite different from Array::Add(), building an array of references instead of objects.

BTW, I still didn't find the bug there... The only thing I found (up to now) is shown in my code here :

	int zzz;
	MyAppWindow *win, *win2;
	win = new MyAppWindow;
	win2 = new MyAppWindow;
	OpenGLExample gl, gl2;
	gl.SetFrame(InsetFrame());
	gl2.SetFrame(InsetFrame());
	win->Add(gl.HSizePos(10, 10).VSizePos(10, 10));
	win2->Add(gl2.HSizePos(10, 10).VSizePos(10, 10));
	win->Sizeable().Zoomable();
	win2->Sizeable().Zoomable();

	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 0
	win->OpenMain();
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 1
	win2->OpenMain();
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 2
	delete win;
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 2 !!!
	delete win2;
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 2 !!!
    Ctrl::EventLoop();

If I suppress the lines :

	win->Add(gl.HSizePos(10, 10).VSizePos(10, 10));
	win2->Add(gl2.HSizePos(10, 10).VSizePos(10, 10));

The code works ok :

	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 0
	win->OpenMain();
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 1
	win2->OpenMain();
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 2
	delete win;
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 1
	delete win2;
	zzz = Ctrl::GetTopCtrls().GetCount(); // zzz = 0

That works even if I leave both lines BUT OpenGLExample is *not* derived from GLControl.
I'd like to know if the bug is Linux-dependent or not... But I haven't an Ide setup on my win xp machine. Don't you have a bit time to test on windows ? Smile

Back to refcounted objects. What about if Ctrl would be an object built with PIMPL idiom and refcounted ? You then could write :

aControl a;  // control is created
aControl b = a; // just reference to inner pimpl object is copied

or, what sound even better:

Vector<Ctrl>*a, *b;
Ctrl c; // control is created, RefCount == 1
a = new Vector<Ctrl>;
b = new Vector<Ctrl>;
a->Add(c); // a gets a *copy* of c, but in reality it adds just to refcount of c, that becomes 2
b->Add(c); // b gets a *copy* of c, but in reality it adds just to refcount of c, that becomes 3
delete a; // a gets destroyed, RefCount in c becomes 2

The advantage of this instead of references of an object ? Well... you must not care of ownership.... and you can be sure object is freed on last reference lost.
As usual, that brings some performance lost.

Ciao

Max

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