Vladimir, Igniters Here are my 2 cents.
The current situation with threading when it comes to executing user callbacks -- the CQ filters (either local or remote), the CQ listeners, the event listeners, the messaging listeners, the entry processors (did I miss anything?) -- is pretty sad. The callbacks may get executed on a system pool's thread, public pool's, utility pool's, discovery worker thread, application thread, to name a few. It causes a lot of grief and suffering, hard-to-fix races, dead locks and other bugs. I guess it's always possible to come up with a more or less reasonable explanation to such predicament (which usually boils down to "It is so because this is how it's implemented"), but I, as a user, could not care less. I want consistency. I want all my callbacks (including Entry Processors!) to be executed on the public pool's threads, to be precise. This is not the first time I complain about this, and I really think it's time to fix this mess. For a good example of how to implement ordered async dispatch of callbacks on large scale, one only needs to look at Akka (or Reactor https://github.com/reactor/reactor). Coherence also managed to get it right (in my opinion, that is). Regards Andrey
