[jboss-jira] [JBoss JIRA] (DROOLS-4565) MVELDialectRuntimeData is not thread safe

MVELDialectRuntimeData is not thread safe ----------------------------------------- Key: DROOLS-4565 URL: https://issues.jboss.org/browse/DROOLS-4565 Project: Drools Issue Type: Bug Components: core engine Affects Versions: 7.16.0.Final Environment: Java 11.0.2 Different OS Reporter: Timo Gutjahr Assignee: Mario Fusco Priority: Major Attachments: ForkJoinPool-1-worker-1.txt, NPE.txt, main.txt MVELDialectRuntimeData#mvelReaders is accessed concurrently but is not thread safe due to the usage of a HashSet. This may cause lost updates. (See [^ForkJoinPool-1-worker-1.txt] and [^main.txt] ) If this happens and the kie base is serialized and deserialized it results in a NullPointerException at runtime. (See [^NPE.txt] ) We observed that the entries in this Set (mvelReaders) are serialized and important for the deserialization step because they contain information about transient objects that have to be re-initialized after deserialization. While losing this information due to concurrent access does not cause problems during compilation, serialization and deserialization of a kie base, they may cause NullPointerExceptions at runtime when transient fields remain uninitialized.