[fpc-pascal] Question: Is there a global callback, when a thread gets terminated?

[Martin]

Lets say you have a unit, with code that can be called from threads.
- The code  does not own the thread object, so it can *not* use 
TThread.OnTerminate (assuming it could get hold of the thread object).
- Yet the code wants to use "threadvar" and create objects (or otherwise 
allocate mem). The code should return the memory, when the thread 
terminates.
- The user of the code should not need to make any calls, to initiate 
the clean up.

So that would need something like
   GetCurrentThreadObject.AddThreadTermationHandler(MyHandler);
or
   GlobalThreadTerminationHandler.Add(MyHandler);

MyHandler does not need the thread-id, or -object. But it needs to run 
in the correct context for the ThreadVar. That is it needs to see the 
value the threadvar has for the thread that is terminating.
So the Handler could do something like "myThreadVar.Free".

Any ideas?

I know the memory manager gets called "MemoryManager.DoneThread".
It is possible to intercept this, by getting the current mem-mgr, 
replacing the method with a wrapper method (calling the original 
method), and setting the mem-mgr.... Not particular nice.