import java.time.Duration;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

/** JEP 444 (final): 10,000 blocking tasks on virtual threads. Timing is machine dependent, so only counts are asserted. */
public class VirtualThreadsDemo {
    public static void main(String[] args) throws Exception {
        AtomicInteger done = new AtomicInteger();
        long t0 = System.nanoTime();
        try (ExecutorService ex = Executors.newVirtualThreadPerTaskExecutor()) {
            for (int i = 0; i < 10_000; i++) ex.submit(() -> { Thread.sleep(Duration.ofSeconds(1)); done.incrementAndGet(); return null; });
        }
        long ms = (System.nanoTime() - t0) / 1_000_000;
        System.out.println("tasks completed : " + done.get());
        System.out.println("finished in < 5s: " + (ms < 5_000) + "   (10,000 x 1s sleeps)");

        Thread v = Thread.ofVirtual().name("demo-vt").start(() -> System.out.println("isVirtual       : " + Thread.currentThread().isVirtual() + ", daemon=" + Thread.currentThread().isDaemon()));
        v.join();
        Thread p = Thread.ofPlatform().name("demo-pt").start(() -> System.out.println("platform isVirtual: " + Thread.currentThread().isVirtual()));
        p.join();
    }
}