System.gc() calls by core APIs

Question

Some of you probably know that some of core java APIs make explicit calls to System.gc(). I know two cases when this happens:

1. NIO. I believe that is done to do

Answer 1

A JDK implementation knows exactly how its own System.gc() behaves. JDK does not have to pretend to be agnostic, restraining itself to the standard abstract behavior, instead of the concrete proprietary behavior (which is of course compliant with the standard behavior)

Yes, it can call System.gc() as it sees fit. We shouldn't.