Hi all guys, sorry for resurrecting a zombie message, but I've been busy at work and haven't had the chance to contribute at all. I could re-start committing code according to the requirements described by Phil, If it works for you, so other tasks like JMX/autoconfigure can be unlocked, please let me know. Have a nice day, Simo
http://people.apache.org/~simonetripodi/ http://www.99soft.org/ On Wed, Nov 3, 2010 at 11:01 PM, Phil Steitz <phil.ste...@gmail.com> wrote: > > > > > On Nov 3, 2010, at 5:03 PM, Steven Siebert <smsi...@gmail.com> wrote: > >>> >>> >>> You restore the pool fields that used to hold the configuration setting >>> properties and leave the getters and setters (for the mutable ones) in >>> place. >>> >>> Phil >>> >>> >> so something like this? >> >> public class GOP extends .... { >> >> /** >> * ref to immutable config reference, immutable config values are either >> referred directly here >> * or are copied to a final instance field >> */ >> private GOPConfig config > > No. There is no config member. It is used only to encapsulate the > parameters of the ctors. The GOP class stores the config data in individual > fields, accessed by getters and setters. The setters at least are > synchronized using the pool monitor. Look at the old code. What I am > proposing is that we limit the use and lifetime of the config objects to the > ctors and/or factories. > > Phil >> >> >> //mutable configuration values are mutated/accessed from pool instance >> private volatile int mut1; //probably better to use read/write locks >> private volatile int mut2; >> >> public GOP (GOPConfig config) { >> this.config = config; >> reconfigure(config); >> } >> >> /** >> * using this model, this method isn't really required (at least not >> public) >> * but would be a convenience for "batch"/atomic changes to configuration >> values - >> * this is possible if we switch from volatile to a r/w locking mechanism >> */ >> public void reconfigure (GOPConfig config) { >> mut1 = config.getMut1; >> mut2 = config.getMut2; >> } >> >> public void setMut1 (int m) { >> mut1 = m; >> } >> >> public int getMut1 () { >> return mut1; >> } >> >> .... >> } >> >> I wonder, with this model....what is the reason for having an immutable >> configuration instance if we're going to copy the values locally for (at >> least) mutability purposes? I believe the attraction of the immutable >> configuration instance was for concurrency issues...but with this model, we >> would need to use pool-local syncronization (locking) anyway. >> >> I wrote a quick mock-up implementation like this, using a >> ReentrantReadWriteLock, and the amount of concurrency work in each >> pool/factory started to pile up. We already identified that inheritance of >> the Pool/Factory classes might not be the best approach (I agree with this >> as well...which would cause POOL-177 to no longer be implemented)...so this >> means duplication of synchronization code as well. >> >> I think I'm falling back to my initial thought on this in that the config >> classes should, IMO, either be mutable (where appropriate) and made thread >> safe (internally synchronized) to reduce the amount of concurrency work >> needed in each class that aggregates the instance...or immutable and any >> changes to the config instance needs to be done by going back to the Builder >> (something like new Builder(configInstance).change().create());) and then >> the config reference in each pool/factory could be made volatile. >> >> I know this is confusing in email....I would be glad to create a quick patch >> or UML for this to clear things up if this would help. >> >> Thoughts? >> >> S > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
