Does WeakReference create a DestroyGCHandle event on garbage collection?

[interwhy]

Hi, I'm investigating a GCHandle leak in an application and I'm having trouble finding documentation in this area. I believe I narrowed the source down through dotnet-trace and perfview to WeakReferences being created causing a SetGCHandle event without any corresponding DestroyGCHandle events, but someone else pointed out that it's not clear if WeakReferences would cause DestroyGCHandle events if they were garbage collected in gen 0.

I found these methods:

runtime/src/coreclr/vm/gchandleutilities.h

Lines 285 to 298 in b83fee9

	inline void DestroyWeakHandle(OBJECTHANDLE handle)
	{
	DestroyHandleCommon(handle, HNDTYPE_WEAK_DEFAULT);
	}
	inline void DestroyShortWeakHandle(OBJECTHANDLE handle)
	{
	DestroyHandleCommon(handle, HNDTYPE_WEAK_SHORT);
	}
	inline void DestroyLongWeakHandle(OBJECTHANDLE handle)
	{
	DestroyHandleCommon(handle, HNDTYPE_WEAK_LONG);
	}

and some of them don't have any references, such as DestroyWeakHandle. Does that mean the DestroyGCHandle event won't be created? I'm not too familiar with the inner workings of the .NET garbage collector, so any help or guidance would be huge for me 😄

[danmoseley]

@Maoni0

[Maoni0]

weakrefs should emit a DestroyHandle event when their finalizer is run in GCToEEInterface::EagerFinalized. this will call DestroyTypedHandle.

[interwhy]

That answers my question, thank you!