Geir> To be clear, "using APR" and "writing in Java" aren't orthogonal, are Geir> they? I would assume that we do need some boundary between the VM Geir> and the underlying OS/Hardware.
You are correct. Any VM will always need a way to call system functions somehow, and on Linux/Windows/etc, this means C ABI calls. Depending on the approach one chooses, some kinds of APIs are simpler to wrap than others, but I think this is not a major issue.
Tom
The OS dependencies of the core harmony VM should be very minimal. In
the case of Jikes RVM, there is a very thin layer of C code that
interfaces to the OS (signals, system calls, bootstrap). OS ports are
fairly straightforward and very well contained within this interface.
Therefore I don't see OS portability as a concern for the core Harmony
VM. Portability of the libraries is a bigger issue.