> Concurrent updates may lead to redundant LambdaForms created and unnecessary > class loading when those are compiled. > > Most notably, it severely affects MethodHandle customization: when a > MethodHandle is called from multiple threads, every thread starts > customization which takes enough time for other threads to join, but only one > of those customizations will be picked. > > Coordination between threads requesting the updates and letting a single > thread proceed avoids the aforementioned problem. Moreover, there's no need > to wait until the update in-flight is over: all other threads (except the one > performing the update) can just proceed with the invocation using the > existing MH.form. > > Testing: > - manually monitored the behavior on a stress test from > [JDK-8252049](https://bugs.openjdk.java.net/browse/JDK-8252049) > - tier1-4
Vladimir Ivanov 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 three additional commits since the last revision: - Minor cleanups - Merge branch 'master' into 8257189.mh.customization.concurrent - Improve concurrent LF customization ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/1472/files - new: https://git.openjdk.java.net/jdk/pull/1472/files/1780f57f..9cf759ed Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1472&range=01 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1472&range=00-01 Stats: 23494 lines in 558 files changed: 13055 ins; 3034 del; 7405 mod Patch: https://git.openjdk.java.net/jdk/pull/1472.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/1472/head:pull/1472 PR: https://git.openjdk.java.net/jdk/pull/1472
