On Sun, Jan 23, 2011 at 10:31 PM, Ken Wesson <kwess...@gmail.com> wrote: > On Sun, Jan 23, 2011 at 8:56 PM, Michael Gardner <gardne...@gmail.com> wrote: >> Suppose I have a sequence of tasks I'd like to parallelize using pmap. The >> amount of CPU time these tasks require varies greatly; in particular, many >> of them will require virtually no work. Can I rely on pmap to divide the >> work efficiently even if there is some pattern to the distribution of easy >> tasks (e.g. clumped at the beginning, or every nth)? Assume it's not >> possible to identify the easy tasks beforehand. > > Here's a little data: > user=> (def printer (agent nil)) > #'user/printer > user=> (defn xyz [n] (send printer (fn [_] println > (Thread/currentThread))) (* n n))
Eh, that's weird. That's not the definition I used. I used (defn xyz [n] (let [t (Thread/currentThread)] (send printer (fn [_] (println t)))) (* n n)) of course so it would be the pmap thread, not the agent thread, in the printout. I had been experimenting with investigating the agent thread pools too, so the defn must have come from that part of the REPL session. This data: > #<Thread Thread[pool-2-thread-25,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-25,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-21,5,main]> > #<Thread Thread[pool-2-thread-21,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-29,5,main]> > #<Thread Thread[pool-2-thread-29,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-22,5,main]> > #<Thread Thread[pool-2-thread-30,5,main]> > #<Thread Thread[pool-2-thread-28,5,main]> > #<Thread Thread[pool-2-thread-26,5,main]> > #<Thread Thread[pool-2-thread-24,5,main]> was generated using the latter defn (the one that captures Thread/currentThread outside the send). -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
