[e-lang] New paper on Scala's actor-based concurrency model

[David Hopwood]

<http://www.scala-lang.org/docu/files/haller07actorsunify.pdf>

Note that the treatment of replies (by implicitly including a reference to
the sender in each request) does not follow POLA: being able to send any
message back to the sender is needlessly greater authority than being able
to send just a reply. Erlang also has this problem.

Apart from that, the implementation of lightweight concurrency on top of
the JVM looks very nice, and the combination of blocking operations with an
actor-based model is interesting. (The method of detecting gridlock resulting
from too few worker threads, described on page 11, seems a bit of a hack, but
never mind.)

-- 
David Hopwood <david.nospam.hopwood at blueyonder.co.uk>