spinettaro/delphi-event-bus

infinite loop in TRTTIUtils.Clone

edwinyzh opened this issue · 5 comments

edwinyzh commented

Hello Daniele,

So I've just started integrating delphi-event-bus into my program.
The first issue I'm experiencing is that, TEventBus.Post will be in a dead-loop in line 162, which calls TRTTIUtils.Clone, which in turn loop infinitely in line 827:

if Field.GetValue(cloned).IsEmpty then
        begin
          targetObject := TRTTIUtils.Clone(sourceObject); // infinite loop here...

I guess it must has something to do with my event definition:

  // Base event about a TWoDoc
  TBaseDocEvent = class(TBaseAppEvent)
  private
    FDoc: TWoDoc;
  public
    property Doc: TWoDoc read FDoc write FDoc;
  end;

Where TWoDoc has properties like

   property ParentDoc: TWoDoc read FDoc write FDoc;
   property NextSibling: TWoDoc read FDoc write FDoc;
   // and so on...

I wish you can shed some light on the issue, thanks.

edwinyzh commented

Update 1:
Fixed the issue by replacing TRTTIUtils.Clone with LEvent := ObjectClone.TObjectClone.From(AEvent);

ObjectClone is from delphihaven.wordpress.com

But I'm not sure if that will introduce any other issues...

spinettaro commented

Hi Edwin,
The RTTIUtilsU.pas is an external unit from Delphi MVC . Can you write a unit test to reproduce the bug ? So I can verify it on DMVC.

edwinyzh commented

I guess the issue is about circular reference of objects, but I'm not sure.
I'm not able to provide a unit test, but if a screen-recording (showing the Delphi IDE's stack tracing ,etc) would help I could make one, and send you privately.

spinettaro commented

Thanks Edwin, but don't worry I'll create the unit test.

spinettaro commented

Removed the internal CloneEvent as the new architecture is interfaced based 307a2cf