When is it acceptable to call GC.Collect?

Question

The general advise is that you should not call GC.Collect from your code, but what are the exceptions to this rule?

I can only think of a few very speci

Answer 1

One useful place to call GC.Collect() is in a unit test when you want to verify that you are not creating a memory leak (e. g. if you are doing something with WeakReferences or ConditionalWeakTable, dynamically generated code, etc).

For example, I have a few tests like:

WeakReference w = CodeThatShouldNotMemoryLeak();
Assert.IsTrue(w.IsAlive);
GC.Collect();
GC.WaitForPendingFinalizers();
Assert.IsFalse(w.IsAlive);

It could be argued that using WeakReferences is a problem in and of itself, but it seems that if you are creating a system that relies on such behavior then calling GC.Collect() is a good way to verify such code.