First of all it depends on the implementation, the language specification doesn't state how it works.

https://en.m.wikipedia.org/wiki/List_of_Java_virtual_machine...

As it stands is mostly done at runtime and only for a).

Otherwise you are better with try-resources, and for something like malloced memory there are off-GC heap APIs.

Also Valhalla will eventually land, although it is getting long by now.

Personally I wish they would move some escape analysis to compile time just to help with memory consumption. I’m assuming it would require byte code changes though.