We'll be talking about multicore programming at NYCJUG tonight, as you may have guessed from some of the titles of the material on the wiki.
On Mon, Mar 8, 2010 at 5:52 PM, Don Guinn <[email protected]> wrote: > I have not updated the WIKI MultiCoreSupport in a while as people wanted to > keep the discussion in the forums. I have played with controlling multiple > J7 sessions from one session and should toss it out soon and see what > sticks. > > On Mon, Mar 8, 2010 at 3:35 PM, Jan Jacobs <[email protected]> > wrote: > > > Dan, > > thanks a lot; this is very helpful information! > > Jan. > > > > On Mon, Mar 8, 2010 at 11:01 PM, Dan Bron <[email protected]> wrote: > > > > > Jan Jacobs asked: > > > > is it possible for a master J-session to initiate other J-sessions > > that > > > run > > > > on separate cores > > > > > > Sure. For example, the follow lines will execute a fresh J session: > > > > > > require 'task' > > > fork BINPATH_z_, PATHSEP_j_ (, }.~ [ i:~ ,) >{.ARGV_z_ > > > > > > Of course it's up to the OS to assign tasks to cores appropriately > (which > > > OSes are pretty good at). > > > > > > In terms of having these new tasks do something useful, the simplest > way > > is > > > to keep them independent (ie. no sharing of data), and > > > simply control their execution through extra command line parameters. > > > > > > If you must share data, or even pass messages, then you're pursuing > > coarse > > > parallelism, which has been discussed in some depth > > > recently. For example, see this thread: > > > > > > > http://www.jsoftware.com/pipermail/chat/2010-February/003190.html > > > > > > (which references a number of previous threads on the same or related > > > topics.) That thread resulted in a Wiki initiative to > > > implement a (user-level, coarse) parallelism utility in J. Don has > > started > > > collecting ideas for that implementation on the Wiki: > > > > > > http://www.jsoftware.com/jwiki/MultiCoreSupport > > > > > > Since it's a favorite of Devon's, we also discuss this topic frequently > > in > > > the NYC JUG, so you might try searching the minutes of > > > our meetings on the Wiki as well (I mean visually -- a lot of our notes > > are > > > scanned in as images, rather than being transcribed as > > > text). > > > > > > But in short, at the moment there's nothing off-the-shelf to help > > > distribute J workload. If you have an immediate need, you'll have > > > to roll something of your own. Shared mapped files (for large data) > and > > > sockets (for asynchronous alerts or messages) provide good > > > starting points. There may be some examples or demonstrations of this > in > > > the Forum archives, if you dig a little. > > > > > > -Dan > > > > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > > > > > > -- > > Jan Jacobs > > Esdoornstraat 33 > > 5995AN Kessel > > T: +31 77 462 1887 > > M: +31 6 23 82 55 21 > > E: [email protected] > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
