I have implemented the performance improvements that I was thinking of using Java 5 concurrency tools, they can be viewed at [1].
I wrote a little performance test suite [2] that tests multithreaded service registry performance (10 threads) from single / multiple bundles with either singleton services and Prototype Service Factory services and the results are quite impressive. I'm getting performance improvements compared to the current trunk from 8 times better than the original (800%) to more than 30 times better (3000%). Carsten has already reviewed the code (thanks Carsten!) and I'm planning to commit it to Felix tomorrow if nobody objects. Cheers, David [1] https://github.com/bosschaert/felix/commit/e6a1b06c6e66d9c98e6d81b91ef7003c8e725450 [2] https://github.com/bosschaert/coderthoughts/tree/master/service-registry-perftest/srperf On 23 March 2015 at 15:39, Richard S. Hall <he...@ungoverned.org> wrote: > On 3/23/15 10:17 , David Bosschaert wrote: >> >> On 23 March 2015 at 13:39, Richard S. Hall <he...@ungoverned.org> wrote: >>> >>> On 3/23/15 03:55 , Guillaume Nodet wrote: >>>> >>>> There's a call to interrupt() in Felix#acquireBundleLock(), not sure if >>>> it >>>> can be the culprit though. >>>> Interrupts could also be caused by a bundle being shutdown while one of >>>> its >>>> thread is waiting for a service, which should is a valid use case imho. >>>> Anyway, I think sanely reacting to a thread being interrupted would be >>>> good. >>> >>> >>> Yes, threads can be interrupted if they are holding a bundle lock and the >>> global lock holder needs the bundle lock. >>> >>> I admit that I do not recall why we ignore the interrupt here, but didn't >>> we >>> implement service lookup so that a bundle lock wasn't necessary? I >>> thought >>> we just checked for the validity of the bundle context before returning >>> or >>> something. Perhaps we felt there was no reason to be interrupted in that >>> case. I really don't know. >> >> I think that the Service Registry could be rewritten to be completely >> free of synchronized blocks using the Java 5 concurrency libraries, > > > Well, that just moves the sync blocks to the library, but yeah sure. > >> which I think would really be a better approach. There is too much >> locking going on in the current SR implementation IMHO. > > > I don't really think there is too much, but it is complicated. > Unfortunately, it is complicated to make sure that locks aren't held while > do service lookups and this is complicated because you can run into cycles, > etc. > > But feel free to try to simplify it. > >> >> This brings the question: can we move to Java 5 (or Java 6) for the >> Framework codebase? AFAIK we're currently still JDK 1.4 compatible but >> I would be surprised if there is anyone who still needs a JDK that >> went end-of-life 7 years ago. > > > At this point, it doesn't really matter to me. > > -> richard > >> >> Best regards, >> >> David > >
