$ java -Djdk.tracePinnedThreads=full NativePinningDemo   (pre-JDK-24 runtime)

java.version=21.0.10
jdk.tracePinnedThreads=full
sleepMillis=200
VirtualThread[#18]/runnable@ForkJoinPool-1-worker-1 reason:NATIVE
    java.base/java.lang.VirtualThread$VThreadContinuation.onPinned(VirtualThread.java:199)
    java.base/jdk.internal.vm.Continuation.onPinned0(Continuation.java:393)
    java.base/java.lang.VirtualThread.parkNanos(VirtualThread.java:635)
    java.base/java.lang.VirtualThread.sleepNanos(VirtualThread.java:807)
    java.base/java.lang.Thread.sleep(Thread.java:507)
    com.ankurm.vtpinning.NativePinningDemo.sleepCallback(NativePinningDemo.java:30)
    com.ankurm.vtpinning.NativePinningDemo.blockingNativeCall(Native Method)
    java.base/java.lang.VirtualThread.run(VirtualThread.java:329)
done

$ java -Djdk.tracePinnedThreads=full NativePinningDemo   (JDK 24+ runtime - flag is inert)

java.version=25.0.4.1
jdk.tracePinnedThreads=full
sleepMillis=200
done