On Fri, 8 Sep 2023 15:54:05 GMT, Alan Bateman <al...@openjdk.org> wrote:
> There are several methods defined by sun.misc.Unsafe that have standard API > equivalents for many years and releases. The change proposed here is to > deprecate, for removal, the park, unpark, getLoadAverage, loadFence, > storeFence, and fullFence methods. Code using these methods should move to > LockSupport.park/unpark (Java 5), OperatingSystemMXBean.getSystemLoadAverage > (Java 6), and VarHandles xxxFence methods (Java 9). > > The following is a summary of a search of 175973022 classes in 484751 > artifacts to get a sense of the usage of these methods. > > - 1290 usages of Unsafe.park. 1195 are libraries that have re-packaged some > version of ForkJoinPool, maybe from the jsr166 repo, maybe an older JDK > release. In the remaining, only Ehcache stands out with 29 matches. It seems > to be one usage but the library seems to copied/shaded into other artifacts. > > - 1322 usages of Unsafe.unpark. 1243 are re-packaged ForkJoinPool. 29 > occurrences are Encache, again one usage but the library seems to > copied/shaded into other artifacts. > > - 22 usages of Unsafe.getLoadAverage. Most of these are one usage in many > published versions of Apache HBase. > > - 339 usages of Unsafe.loadFence, 1057 usages of Unsafe.storeFence, 517 > usages of Unsafe.fullFence. A handful of these are libraries with copies of > j.u.concurrent, the rest seem to be high performance libraries that support > older JDK releases or just haven't been updated to use VarHandles yet. Happy to see these methods start their journey towards eventual removal. ------------- Marked as reviewed by iris (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/15641#pullrequestreview-1618280143
