It seems like something like this may be relatively simple to try with our gtk port as well. Enumerate each native method and, instead of calling the native methods directly, simply write the function enumeration and parameter values to a queue of sorts. The native command processor would be pretty simple to write.
I think it would be simple at a first look, however to write a good performing implementation (which is the goal of all this imho) is another story. Just choosing a NIO-Buffer which does not need to do any conversation oif the platform has the "needed" endianess brought a large performance boost to Sun's implementation. However sounds pretty interresting ... lg Clemens