As much as I agree with your decision, it just makes me sad. I know lots of people that learned scala for "actors are the way of the future".... I think we need to push harder. Hopefully all major projects migrating off actors will give EPFL a wake up call?
- Josh On Tue, Sep 29, 2009 at 1:41 PM, David Pollak <feeder.of.the.be...@gmail.com > wrote: > > > On Tue, Sep 29, 2009 at 2:35 AM, Stuart Roebuck > <stuart.roeb...@gmail.com>wrote: > >> >> Apologies if I've missed something obvious but my web search hasn't >> turned anything up... >> >> What are the Scala Actors instability issues? I'm in the process of >> doing some major Scala development work and this comment raises >> concerns that I'd like to understand. >> > > The issues (with the Scala Actors in general and Lift's use of them) are: > > - Scala Actors use a custom version of Doug Leah's Fork/Join library. > This was necessary for JDK 1.4 support. With JDK 1.5, the > java.util.concurrent stuff should have been used. I was led to understand > that this change was made in Scala 2.7.5, but it was not and even the Scala > 2.8 stuff still contains fork-join. The FJ library has a memory retention > issue where it trades memory for non-locking performance and, with many > threads in a thread-pool, this leads to out of memory issues. > - The Scala Actor code is very brittle. See > http://erikengbrecht.blogspot.com/2009/01/refactoring-scala-actors.html > The code has not been materially refactored, which means that even in 2.8, > there will be significant potential problems with the Actors. Those > potential problems have manifest themselves as real problems in 2.7.x. I > have spent in aggregate nearly 3 weeks of my time since November 2008 > working around the defects in the Actor library. It's easier to have our > own Actors (the current Actor library is about 2 days of work on my part > and > the refactoring of Lift to work with the existing Actor library is another > 2 > days of work.) > - EPFL has been generally slow to respond to bug reports. I am very > frustrated and quite frankly tired of having to cajole EPFL into responding > to defects in one of the premier Scala libraries. > > I would strongly suggest that you look at Akka. It's got a better view and > implementation of Actors than does the standard Scala distribution. Akka > includes support for distributed actors, etc. > > Hope this helps. > > >> >> Best, >> >> Stuart >> >> On Sep 29, 3:30 am, David Pollak <feeder.of.the.be...@gmail.com> >> wrote: >> > Folks, >> > >> > Given the continued instability of Scala Actors, I've decided to remove >> them >> > from Lift. >> > >> > Specifically, I'm migrating CometActors to sit on top of Lift's Actors. >> > But, you'll also be able to use Akka Actors to power Lift's CometActors. >> > Specifically, I'm working with Jonas to make sure that we share a common >> > interface to Actors. >> > >> > I've gotten Lift nearly completely migrated over to Lift's Actors on the >> > dpp_wip_actorize branch. Seehttp:// >> github.com/dpp/liftweb/tree/dpp_wip_actorize >> > >> > There will be some breaking changes to your applications. Specifically: >> > >> > - Box will be moved to a new package, net.liftweb.base (this is where >> the >> > interface for Actors will live as well) >> > - If you make any assumptions about your CometActors being Scala >> Actors >> > (e.g., using linking), you will have to rewrite this code >> > - Some methods in Lift that currently take Scala Actors as parameters >> > will take Lift Actors (e.g., ActorPing) >> > >> > There will be a parallel Maven repository with the new Lift Actor stuff >> in >> > it so you will be able to build you apps against the new code before the >> > official switch-over. >> > >> > Milestone 6 (which should be out next week) will be based on the >> existing >> > Actor model. After we get feedback from the community about the new >> Actor >> > stuff, we will switch -SNAPSHOT over to the new Actor stuff. >> > >> > Questions, thoughts, or comments? >> > >> > Thanks, >> > >> > David >> > >> > -- >> > Lift, the simply functional web frameworkhttp://liftweb.net >> > Beginning Scalahttp://www.apress.com/book/view/1430219890 >> > Follow me:http://twitter.com/dpp >> > Surf the harmonics >> >> >> > > > -- > Lift, the simply functional web framework http://liftweb.net > Beginning Scala http://www.apress.com/book/view/1430219890 > > Follow me: http://twitter.com/dpp > Surf the harmonics > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Lift" group. To post to this group, send email to email@example.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~----------~----~----~----~------~----~------~--~---