ProcDict leak in trace handler

[gomoripeti]

The trace handler process stores start time and arguments for each function call in its process dictionary so that it can fetch it when the function returns. However it is possible that the function finished event (return_from or exception_from) never returns. (Eg. the function does an infinite loop or calls another function that does that. Or the process executing the function exits/gets killed without crashing)

One idea is to garbage collect such entries from the procdict removing those older than max_duration.

[gomoripeti]

Actually if the process exits or is killed then an exception_from message will still be received. So the only problem is with infinite loops. But that's also only when ignore_recursion is false or there are growing number of processes with infinite loops in the system.
On the other hand, tracing can affect tail recursive calls negatively (citation needed) so it's better to avoid them.