There was a little drama that played out as Java was getting a proper JIT.
In one major release, there was a bunch of Java code responsible for handling some UI element activities. It was found to be a bottleneck, and rewritten in C code for the next major release.
Then the JIT became properly useful, and the FFI overhead was more than the difference between the hand-tuned C code and what the JIT would spit out on its own. So in the next major release, they rolled back to the all-Java implementation.
Java had a fairly reasonably fast FFI for that generation of programming language, but they swapped for a better one a few releases after that. And by then I wasn't doing a lot of Java UI code so I had stopped paying attention. But around the same time they were also making a cleaner interface between the platform-specific and the general Java code for UI, so I'm not entirely sure how that played out.
But that's exactly the sort of see-sawing you need to at least keep an eye out for when doing this sort of work. Would you be better off waiting a couple milestones and saving yourself a bunch of hand-tuning work, or do you need it right now for political or technical reasons?
In one major release, there was a bunch of Java code responsible for handling some UI element activities. It was found to be a bottleneck, and rewritten in C code for the next major release.
Then the JIT became properly useful, and the FFI overhead was more than the difference between the hand-tuned C code and what the JIT would spit out on its own. So in the next major release, they rolled back to the all-Java implementation.
Java had a fairly reasonably fast FFI for that generation of programming language, but they swapped for a better one a few releases after that. And by then I wasn't doing a lot of Java UI code so I had stopped paying attention. But around the same time they were also making a cleaner interface between the platform-specific and the general Java code for UI, so I'm not entirely sure how that played out.
But that's exactly the sort of see-sawing you need to at least keep an eye out for when doing this sort of work. Would you be better off waiting a couple milestones and saving yourself a bunch of hand-tuning work, or do you need it right now for political or technical reasons?