I wish the threading design for parrot would look more toward
successful, performant multithreaded systems, rather than setting up new
design experiments based upon the results of failed experiments (in
particular, all forms of Perl 5 threading). I think that
environment-cloning and fine-grained locks have both been adequately
proven antithetical to what is expected from threads: Lightweight,
low-overhead concurrency. Environment cloning is high-performance, but
high overhead. Fine-grained locks are low overhead, but low-performance.

—

Gordon Henriksen
malic...@mac.com