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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for March 24th, 2015

Interfaces are great, but they can be a pain to debug. Forgetting one weak link can lead to Access Violation hell…

Posted by jpluimers on 2015/03/24

Paul Thornton posted a nice question on G+ two weeks ago:

Interfaces are great, but they can be a pain to debug. Forgetting one weak link can lead to Access Violation hell. I seem to remember a utility that would let you visualise the links between interfaced objects, but can’t remember what it was called. Anybody know?

Do you have any clever interface debugging tips or tricks?

Mixing object and interface references leads to complex situations, especially when some classes make refcounting go away (not limited to UI components) so refactoring is a good idea, it at all possible:

Lars Dybdahl:

Refactor them away :-)

When the mix of interface reference counting and TObject gets so complex, that the source code is no longer obvious, maintenance costs sometimes become too high and another solution might be better.

Nicholas Ring:


+Lars Dybdahl Totally agree and it is even worse when reference counting is disabled (like adding an interface reference to an UI component).


There is not much tooling, this thread only mentioned RefCountTracer and FastMM:

Steffen Binas:

There is this:

It helps you find memoryleaks, but also could show you if a refcount goes below 0.

Paul Thornton:

This link was very useful. It also points to a good FastMM tutorial.

Which reminded me I totally forgot to post that tutorial on my blog so here it is:

Read the rest of this entry »

Posted in Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Delphi XE6, Delphi XE7, Development, Software Development | 2 Comments »

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