On Monday, December 8, 2014 3:34:05 PM UTC-5, Michał Marczyk wrote: > > On 8 December 2014 at 17:54, Andy L <core....@gmail.com <javascript:>> > wrote: > >> But I'd personally just use a delay rather than "locking" for this > >> purpose. > > > > > > It is not that I like locking at all. However I still fail to see, how > in a > > multithreaded context memoize/cache prevents executing a given function > more > > than once (which I want to avoid at any cost here) since cache lookup > and > > swap! does not seem to be atomic : > > > https://github.com/clojure/core.cache/blob/master/src/main/clojure/clojure/core/cache.clj#L52 > > > When you say > > (delay (foo)), > > foo will be called at most once, regardless of how many times you > deref (@) / force the delay. (If you never force the delay, it will > not be called at all.) The way this is enforced is through making > deref a synchronized method on delays. >
Which means it's locking or bust. You just get to either do the locking yourself or delegate :) -- 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.
