Branch: refs/heads/master Home: https://github.com/resteasy/Resteasy Commit: 6866e3ff2cd74402fb7250c50690ab31c39271a2 https://github.com/resteasy/Resteasy/commit/6866e3ff2cd74402fb7250c50690a... Author: Alessio Soldano <asoldano(a)redhat.com&gt; Date: 2019-07-18 (Thu, 18 Jul 2019) Changed paths: M providers/jackson2/src/main/java/org/jboss/resteasy/plugins/providers/jackson/ResteasyJackson2Provider.java Log Message: ----------- [RESTEASY-2304] ResteasyJackson2Provider: fix ConcurrentHashMap contention (#1985) Replace Jackson's AnnotationBundleKey with an implementation that uses `.equals()` instead of `==` to compare annotations. AnnotationBundleKey assumed annotation references were unique which breaks because the JRE doesn't cache parameter annotations, returning new references each time parameter annotations are queried. This was causing a severe performance degradation over time since matching ClassAnnotationKey instances had the same `hashCode` while failing equality checks, leading to a large and growing single bucket with identical objects and lock contention.