The implementation in java.util.jar.JarFile, when initializing a JarVerifier uses the jdk.internal.misc.ThreadTracker to mark the current thread as initializing a JAR verifier. This state on the current thread is then enquired in a different part of the JDK code.

ThreadTracker was a temporary mechanism. ScopedValue has been delivered as a permanent Java SE feature in Java 25 (JDK-8352695). The JarFile implementation should move away from ThreadTracker and instead use ScopedValue in its place.