This patch applies on top of JDK-8234338, which introduced ZHeuristics, and move the heuristics code in ZWorker into ZHeuristics. No logic changes, just code motion. Bug: https://bugs.openjdk.java.net/browse/JDK-8234361 Webrev: http://cr.openjdk.java.net/~pliden/8234361/webrev.0 /Per