[slime-devel] Re: Partial multiprocessing support on CMUCL

[Peter Seibel]

Luke Gorrie <luke at bluetail.com> writes:

> HELP, HELP! SAVE ME! I don't know how to write correct multithreaded
> programs!
> 
> How do people do synchronization in Lisp? Do you use higher-level
> abstractions than locks and shared variables, or is there some book
> I can read to actually understand how to program with those things?

Okay, so your claim of ignorance that is probably largely
tongue-in-cheek, but just in case, Doug Lea's, _Concurrent Programming
in Java_ is pretty good despite the obvious Java focus. And you
definitely want to check out Hoare's paper, _Monitors: An Operating
System Structuring Concept_[1] if you haven't already.

> The mind boggles. Please someone stop me before I write a homebrew
> message-passing system.

It seems to me that you want to make your own event queue--have the
single thread doing the IO and putting work requests on queues for
other threads to pick up and actually do the work. (To the extent I
understand Erlang, this should be quite familiar--you just have to
roll it yourself. Though there may be certain data structures other
than the queues that need to be accessed concurrently which makes it
less like Erlang. Again, as I understand Erlang which is not very much
at all.) Of course that may be what you meant by a homebrew
message-passing system. In which case, go for it.

-Peter

[1] <http://www.acm.org/classics/feb96/>

-- 
Peter Seibel                                      peter at javamonkey.com

         Lisp is the red pill. -- John Fraser, comp.lang.lisp