On Feb 15, 7:17 am, bOR_ <boris.sch...@gmail.com> wrote: > Getting a bit confused again. It seems possible to make counters from > agents, atoms and refs ... > Is there a time and place for all three of them? I am leaning towards > always using the agent, as it can be send from transactions when the > transaction finishes.
There's a place for all three, but not necessarily for counters. Here's a good discussion: http://groups.google.com/group/clojure/msg/fd0371eb7238e933 And here's an example of encapsulating a counter in a function: http://groups.google.com/group/clojure/msg/1ee509f9cbcfa3f2 You probably don't want to use an agent for a counter, since multiple threads might read (deref) the same value before it gets updated. If you're using the counter within a transaction (dosync), your counter must be a ref. You should not modify (swap!) an atom inside a transaction, because the transaction may be retried. Modifying an atom is a side effect, and side effects should not happen in transactions. If you're not using refs/transactions, then your counter can be an atom. -Stuart Sierra --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
