"As far as I understand, the step-function of a transducer is never(?) accessed concurrently by more than 1 thread."
It's actually "one thread at a time". And you're right, stuff like Core.async may bounce a transducer between several different threads, but only 1 thread "owns" it at a given time. Timothy On Fri, Jan 2, 2015 at 7:11 AM, Jörg Winter <jwin1...@gmail.com> wrote: > Hi, > > As seen in this example of a stateful transducer... > > http://crossclj.info/ns/org.clojure/clojure/latest/clojure.core.html#_partition-by > > ... I am wondering what is the concrete motivation behind using > 'volatile!' instead of say a simple (mutable) Java-Object wrapper ? > In the partition-all example, an ArrayList is used for aggregating the > 'temporary' results for the step-function, so this mutable state is not > concerned with threading at all. > Why then is there a threading-concern with pv (the volatile!) ? > > As far as I understand, the step-function of a transducer is never(?) > accessed concurrently by more than 1 thread. > > Is volatile! necessary because transducers should be usable with > core.async ? > Or is it just an easy way to get a mutable object in Clojure ? > > > Best, > Joerg > > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- “One of the main causes of the fall of the Roman Empire was that–lacking zero–they had no way to indicate successful termination of their C programs.” (Robert Firth) -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
