[fsdjkflsjfsoij]

Java requires a much more advanced GC and JIT because Java programs tend to allocate a lot more and have extremely bad memory layout when you're not restricting yourself to primitives. Project Valhalla's value types will significantly improve the situation. Relying so heavily on the JIT also has other problems especially in programs that have widely varying execution paths.

[kaba0]

Surely, that’s the incentive part for why the team spent many many work hours improving their GC - just because the JVM typically depends more on a good GC doesn’t make it any less useful - long running processes do make significant use of automatic memory management.

Also, Java’s GCs are moving/compacting GCs, so while the immediate memory representation is indeed inefficient, again, for long running processes Java will place often together-used objects physically close to each other, and will defragment the heap. But Valhalla can’t come soon enough, I agree.

> Relying so heavily on the JIT also has other problems especially in programs that have widely varying execution paths

Has it? I would think that an AOT program would have a worse time with widely varying execution paths, while a JIT compiler is free to reoptimise based on changing application state.

[geodel]

> just because the JVM typically depends more on a good GC doesn’t make it any less useful -

I mean it feels like personal choice. Do I praise the spouse when they bring whole kitchen down while making a dish and cleaning up quickly afterwards? Or do I take it as "Well, you made mess so it was basic expectation from you to clean up fast for later use"

[kaba0]

I would wager that most applications have plenty of object lifetimes that are not regular at all — a web server with some stateful sessions for example. So your analog doesn’t really make sense — go can’t avoid these situations at all and will significantly perform worse in these cases.