On Fri, 21 Jan 2022 23:51:02 GMT, liach <d...@openjdk.java.net> wrote:
>> Upon review of [8261407](https://bugs.openjdk.java.net/browse/JDK-8261407), >> by design, duplicate initialization of ReflectionFactory should be safe as >> it performs side-effect-free property read actions, and the suggesting of >> making the `initted` field volatile cannot prevent concurrent initialization >> either; however, having `initted == true` published without the other >> fields' values is a possibility, which this patch addresses. >> >> This simulates what's done in `CallSite`'s constructor for >> `ConstantCallSite`. Please feel free to point out the problems with this >> patch, as I am relatively inexperienced in this field of fences and there >> are relatively less available documents. (Thanks to >> https://shipilev.net/blog/2014/on-the-fence-with-dependencies/) > > liach 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 four additional commits since the > last revision: > > - Merge branch 'master' into 8261407-reflectionfactory > - Merge branch '8261407-reflectionfactory' > - Just use volatile directly to ensure read order > - 8261407: ReflectionFactory.checkInitted() is not thread-safe The addition of `@Stable` seems safe. Here's a comparison for the `checkInitted` method under current patch (volatile) and the stable annotation (stable): https://gist.github.com/b6a1090872e686f31595bcd778893e82 Under this test setup: https://gist.github.com/96018d7dcaa07763d1c205017a9bd99f Can any professional review the comparison above, as I am not as acquainted to C assembly and VM internals to confirm there is indeed no unintended side effects? ------------- PR: https://git.openjdk.java.net/jdk/pull/6889
