Where we find JVM code in Java source code?

We have two places where we have garbage collector algorithms. One uses a general generation framework and starts in src/share/vm/memory/genCollectedHeap.[hc]pp and continues in the files named gen*, *Generation, *Space, etc. The second uses a less flexible (but more efficient?) class hierarchy and is in src/share/vm/gc_interface/ and src/share/vm/gc_implementation/.

The whole thing hangs together because of the meta-circular class hierarchy for references garbage-collectably objects defined in src/share/vm/oops/oopsHierarchy.hpp and implemented by the other files in that directory.

All the GC code depends on inline code for allocation and for remembered set maintenance that is mostly implemented in the runtime compilers. You'll see what we call "slow-path" implementations of those operations (e.g., for use by the interpreter), but mostly we try to avoid using those methods for performance reasons. (There's a fair amount of complexity to achieve performance.)

The algorithms themselves have been described in various talks and papers, but not with all the complexities you'll see in the code. Can we (the Sun GC team) help you in your analysis? We are always interested in what people find in our code.

Peter.Kessler@Sun.COMa at 2007-7-14 16:58:03 >