[raggi]

Java behavior is in general/abstract similar to .net - there are types & APIs to pin memeory for ffi and aliasing use cases but normal references are abstracted enabling the gc to perform compaction/moves for non pinned objects. The behavior I described in the parent post was go, which exposes pointers directly, rather than references.

It is still possible to end up with fragmentation challenges with both the jvm and .net under specific circumstances- but there are also a lot of tunable parameters and so on to help address the problem without substantially modifying the program design to fit an under specified contract with the memory subsystem. In go there are few tunables, and an even less specified behavior of the gc and its interaction with application code at this level of concern.