Julian Hyde created CALCITE-4986: ------------------------------------ Summary: Make HepProgram thread-safe Key: CALCITE-4986 URL: https://issues.apache.org/jira/browse/CALCITE-4986 Project: Calcite Issue Type: Bug Reporter: Julian Hyde
{{HepProgram}} uses mutable fields for its working state and is therefore not thread-safe. If two threads are planning queries simultaneously and are using the same {{HepProgram}} instances they might conflict with each other. I suspect that this happens several times in Calcite's standard set of rules. This change would move the mutable state out of {{HepProgram}}, so that {{HepProgram}} is fully immutable and therefore thread-safe. It would also modernize some of the internals; for instance, {{class HepInstruction.MatchLimit}} has a field {{int limit}} that could be made final and assigned in the constructor. -- This message was sent by Atlassian Jira (v8.20.1#820001)