On Tue, Oct 12, 2010 at 4:22 PM, Damian Conway <dam...@conway.org> wrote: > The problem is: while most people can agree on what have proved to be > unsatisfactory threading models, not many people can seem to agree on > what would constititute a satisfactory threading model (or, possibly, models). > > What we really need is some anecdotal evidence from folks who are actually > using threading in real-world situations (in *any* languages). What has worked > in practice? What has worked well? What was painful? What was error-prone? > And for which kinds of tasks?
Most languages either implement concurrency in a way that's not very useful (CPython, CRuby) or implement it in a way that's slightly (Java/C/C++) to totally (perl 5) insane. Erlang is the only language I've worked with whose threads I really like, but sadly it's rather weak at a lot of other things. In general, I don't feel that a shared memory model is a good fit for a high level language. I'm very much a proponent of message passing. Unlike shared memory, it's actually easier to do the right thing than not. Implementing it correctly and efficiently is not easier than doing a shared memory system though in my experience (I'm busy implementing it on top of ithreads; yeah I'm masochist like that). > And we also need to stand back a little further and ask: is "threading" > the right approach at all? Do threads work in *any* language? Are there > better metaphors? > > Perhaps we need to think more Perlishly and reframe the entire question. > Not: "What threading model do we need?", but: "What kinds of non-sequential > programming tasks do we want to make easy...and how would we like to be > able to specify those tasks?" I agree. I would prefer implicit over explicit concurrency wherever possible.
