Thread: Good practice to detect lapsed observers

Hi there.

I am working a lot with the observer pattern in my current application. Each object is, on average, observing 3 other objects. And I fear that maybe sometimes I might miss to correctly remove observers that I have previously registered. This might lead to the lapsed observer problem and memory leaks which I would like to avoid.
Unfortunately, there is no compile-time way of detecting this, so I thought about implementing a run-time detection mechanism to throw an exception when a lapsed observer is detected.

But I dont quite now how to do this. I have one idea although it does not sound too solid to me:
I will add a finalize() method to all my observable objects. In this method they will check if there are any observers left observing them. If there are, this will be logged to let me know.
But I dont think this would be able to detect all of them. Are there any other thoughts or suggestions? Any input on this is greatly appreciated.

Thanks in advance.

It solves the problem of leaking memory, but it is not as clean as simply removing the observers when they are not needed anymore. I would prefer it to have my objects clean up after them instead of having the observer lists filter themselfs for unused garbage. If that makes sense.

Do you have any personal experience with weak references? Because I dont and I dont know if the code I posted in the other thread is actually correct.
The problem is that its very hard to test whether it works because of how unpredictable the garbage collector can be.

Thank you for the advice, I will see what I can do.
by the way, I guess it doesnt hurt to have the finalize method log information as well, just for good measure.