On Fri, 8 Jul 2022 10:16:33 GMT, John Hendrikx <jhendr...@openjdk.org> wrote:
>> John Hendrikx has updated the pull request with a new target base due to a >> merge or a rebase. The incremental webrev excludes the unrelated changes >> brought in by the merge/rebase. The pull request contains 27 additional >> commits since the last revision: >> >> - Merge branch 'openjdk:master' into feature/fluent-bindings >> - Add null checks in Subscription >> - Update copyrights >> - Move private binding classes to com.sun.javafx.binding package >> - Add note to Bindings#select to consider ObservableValue#flatMap >> - Fix bug invalidation bug in FlatMappedBinding >> >> Also fixed a secondary issue where the indirect source of the binding >> was unsubscribed and resubscribed each time its value was recomputed. >> >> Add additional comments to clarify how FlatMappedBinding works. >> >> Added test cases for these newly discovered issues. >> - Fix typos in LazyObjectBinding >> - Rename observeInputs to observeSources >> - Expand flatMap javadoc with additional wording from Optional#flatMap >> - Add since tags to all new API >> - ... and 17 more: https://git.openjdk.org/jfx/compare/71632011...d66f2ba6 > > Remember this program? :) > >> ``` >> // Sample program that shows stub leakage: >> public static void main(String[] args) throws InterruptedException { >> StringProperty x = new SimpleStringProperty(); >> >> // Startup >> Thread.sleep(20000); >> >> for(int i = 0; i < 10000000; i++) { >> new SimpleStringProperty().bind(x); >> } >> >> // Bindings added >> System.gc(); // 400 MB of uncollectable stubs does not get GC'd >> Thread.sleep(20000); >> >> // Triggers "stub" clean-up (which fails miserably because of lots of >> array copying) >> x.set("A"); >> >> System.gc(); >> Thread.sleep(20000); >> } >> ``` >> >>  > > I modified `ExpressionHelper` to use a custom `Collection` class that has > `O(log N)` performance for the only things it uses (add at end, remove a > specific listener, iteration). It has the exact same characteristics as > `ArrayList`, that is, it is ordered, it allows duplicates and it maintains > the exact positions when duplicates are part of the list, which means the > call order of listeners is exactly the same (a `LinkedHashMap<Listener, > counter>` would not have this characteristic). Furthermore, it is very > similar to an `ArrayList`, which means relatively low overhead (there is no > `Entry` wrapper for each item in the "list") and good cache locality when > iterating. > > Performance looks now like this: > >  > > The price for this is increased memory use (you can see that having > 10.000.000 binding stubs took around 400 MB before, and now it takes about > twice that). The extra memory use is only paid when there is more than 1 > listener (as per how `ExpressionHelper` operates). @hjohn If there are no more questions or concerns raised in the next few hours, you can integrate this PR. Please file the follow-up JBS bug to address the cleanup. ------------- PR: https://git.openjdk.org/jfx/pull/675
