On Fri, 17 Mar 2023 05:49:45 GMT, Jaikiran Pai <j...@openjdk.org> wrote:
>> Massive parallel execution of parametrised CorpusTest junit tests revealed >> race condition in >> `ClassHierarchyImpl.CachedClassHierarchyResolver::getClassInfo`. >> >> The race condition may skip calculation of the ClassHierarchyInfo. In this >> specific case it caused SegmentScope not being identified as an interface >> and verify error on assignability between declared method return type and >> actual returned type has been emitted by the test. >> >> Proposed patch fixes the race condition in >> `ClassHierarchyImpl.CachedClassHierarchyResolver::getClassInfo`. >> >> Please review. >> >> Thank you, >> Adam > > src/java.base/share/classes/jdk/internal/classfile/impl/ClassHierarchyImpl.java > line 133: > >> 131: //using NOPE to distinguish between null value and >> non-existent record in the cache >> 132: //this code is on JDK bootstrap critical path, so cannot >> use lambdas here >> 133: var res = resolvedCache.getOrDefault(classDesc, NOPE); > > `resolvedCache` is a `Collections.synchronizedMap` backed by a `HashMap`. So > the `getOrDefault()` (internally) synchronizes on the `resolvedCache` > instance itself and thus this operation would be thread safe in context of > access to this cache in rest of this code. So what you propose here looks > good to me. Thank you. ------------- PR: https://git.openjdk.org/jdk/pull/13037
