On Thu, 7 Sep 2023 11:13:44 GMT, Per Minborg <pminb...@openjdk.org> wrote:
> This PR outlines a solution for making immutable maps `@ValueBased` by > removing cacheing of certain values in `AbstractMap`. > > By removing these caching fields in `AbstractMap`, we can make the immutable > maps `@ValueBased` and at the same time, performance is likely improved > because the JVM is probably able to optimize away object creation anyway via > escape analysis. Also, all maps will occupy less space as we get rid of a > number of objects and references stored for each map. > > We need to benchmark this solution to better understand its implications. src/java.base/share/classes/java/util/AbstractMap.java line 318: > 316: * and returned in response to all subsequent calls. No > synchronization > 317: * is performed, so there is a slight chance that multiple calls to > this > 318: * method will not all return the same set. The `@implSpec` above is now outdated since caching is removed. src/java.base/share/classes/java/util/AbstractMap.java line 372: > 370: * returned in response to all subsequent calls. No synchronization > is > 371: * performed, so there is a slight chance that multiple calls to this > 372: * method will not all return the same collection. Same outdated `@implSpec` ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/15614#discussion_r1330809911 PR Review Comment: https://git.openjdk.org/jdk/pull/15614#discussion_r1330809969
