Totally agree. My original aim was to use an idea I had about the way the garbage collector synchronises in the Oracle JVM to give 'windows' of determinism. So I set about making a program to push the gc really hard so I could see if my idea worked. But I have not gotten as far as the original aim yet because I found this interesting stuff about the G1 collector.

As for your points about realtime - I am completely with you. I had in my mind that one might have a realtime system on the rtjvm or in c++ which needed to periodically communicate with a standard JVM. There are three approaches I could see for this. One, would be to send messages and decouple that way. Another is to make the communication abort if it looked like it might cause a deadline miss. The third was to briefly (milliseconds) disable the gc in the standard JVM so the communication could occur and then turn it back on again immediately afterwards.

Now - that sounds like a really bad idea and it probably is - but it is an interesting idea to play with.

So - please don't thing I am proposing realtime programming on the standard JVM, just some ideas for larger systems integration.