MGD swarm-support Mar. 27, 2001
There's a lot that can be done to speed-up models, but the first step is
to get profiling information.  (e.g. jdkswarm -Xprof)

Some of the options are:

  0) Algorithmic optimizations -- profiling makes these obvious

  1) Use language-specific homogeneous ForEach FActions -- that
     eliminates method dispatch costs and cross language lookups.

  2) Likewise, schedule simple actions with language-specific `FActions'.

  3) Identify places where cross languages calls are expensive and 
     substitute pure Java code.  Or, even better, contribute features to Swarm
     so that they run in fast chunks for native-code performance. 

  4) Use the GNU Java compiler, gcj, to compile the model and Swarm
     stubs down to native code.  I recently submitted changes to GCJ
     to make this work.  See the java@gcc.gnu.org mailing list
     archives if you want to fool around with it.  The result of this
     is you get a simple executable.  (Unlike what I talked about at
     SwarmFest last year this doesn't involve a JVM at all.)
  
     The model I'm working on now had about a 1.3 factor speedup without any 
     other changes.  Also, the quality of profiling information from this
     is much better than from JVMs, since it goes all the way down
     through Java runtime support, Swarm itself, and system C libraries.