Hello! Please review the updated patch (no sponsorship is necessary; review only): https://cr.openjdk.java.net/~tvaleev/webrev/8176894/r3/ https://bugs.openjdk.java.net/browse/JDK-8176894
The difference from the previous version [1] is minimal: I just noticed that the specification for computeIfAbsent should say "mapping" instead of "remapping", so I fixed the spec. No changes in code/tests. Also please review the associated CSR: https://bugs.openjdk.java.net/browse/JDK-8227666 I updated it, according to Joe Darcy's comments. An additional explanation and background is copied below from my original e-mail [2] for your convenience: The patch was originally submitted by Sergey Kuksenko in March 2017 and reviewed by some people: http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-March/046825.html The latest patch submitted by Sergey is here: http://cr.openjdk.java.net/~skuksenko/corelibs/utils/8176894/webrev.01/ I asked Sergey why it was abandoned. Seems there were no particular reason and Sergey asked if I could pick up this work. I will be happy to finish it. Here's the list of differences between the latest Sergey patch and my patch: - A bug is fixed in putIfAbsent implementation. TreeMap.java, lines 576 and 596: `|| oldValue == null` condition added (the null value should be overwritten no matter what) - A testcase is added to cover this problem (InPlaceOpsCollisions.java, also checks HashMap and LinkedHashMap). Not sure if it's the best place for such test though. Probably a separate file would be better? - TreeMap.merge() implementation is added. - TreeMap is added to the FunctionalCMEs.java test (btw this file copyright says that it's a subject to Classpath exception which is probably wrong?) - Simple microbenchmark is added: TreeMapUpdate.java My quick benchmarking shows that optimized version is indeed faster for the most of the tests and no regression is observed for put() method. Here's raw results of jdk13-ea+26 and jdk13-ea+26+patch if anybody is interested. http://cr.openjdk.java.net/~tvaleev/jmh/JDK-8176894/ With best regards, Tagir Valeev. [1] https://cr.openjdk.java.net/~tvaleev/webrev/8176894/r2/ [2] https://mail.openjdk.java.net/pipermail/core-libs-dev/2019-July/061309.html
