package com.ankurm.vthreads;

/**
 * Standalone (no Spring context) check that -Djdk.tracePinnedThreads=full is inert on this
 * JDK. Pre-JDK-24, this flag made the JVM print a stack trace to stdout every time a virtual
 * thread pinned its carrier. JEP 491 removed the property along with most of the pinning it
 * used to report on: "setting it on the command line will have no effect." Run via
 * scripts/check-trace-pinned-threads-removed.sh, which invokes this twice (with and without
 * the flag) and diffs the output. See docs/03-pinning-diagnosis.md.
 */
public class PinningTraceCheckMain {
    public static void main(String[] args) throws Exception {
        System.out.println("java.version=" + System.getProperty("java.version"));
        System.out.println("jdk.tracePinnedThreads=" + System.getProperty("jdk.tracePinnedThreads"));
        System.out.println("Running a virtual thread that holds a monitor across Thread.sleep(200)...");
        Thread vt = Thread.ofVirtual().start(() -> {
            try {
                PinningDemoService.doWorkHoldingMonitor(200);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        vt.join();
        System.out.println("Done. If jdk.tracePinnedThreads still worked on this JDK, a pinned-thread " +
                "stack trace would have printed above while the virtual thread was inside doWorkHoldingMonitor.");
    }
}