Main.java

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;

public class Main {


  public static void main(String[] args) {
    try {
      new Main().doIt();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }


  private void doIt() throws Exception {
    var tot = new AtomicLong();
    var c = new AtomicLong();
    List<Thread> threads = new ArrayList<>();
    for (var i = 0; i < 5000000; i++) {
      final long l = i;
      Thread t = Thread.startVirtualThread(() -> {
        long res = method1(l, l + 1, l + 2, l + 3);
        tot.addAndGet(res);
        c.incrementAndGet();
      });
      threads.add(t);
    }

    long start = System.currentTimeMillis();
    while (System.currentTimeMillis() - start < 10000) {
      printMemory();
      Thread.sleep(1000);
    }

    System.out.println("Waiting for threads to complete");
    for (Thread t: threads) {
      t.join();
    }
    System.out.println("Threads complete");

    System.out.println(tot.get());
    System.out.println(c.get());
  }
  
  long method1(long l1, long l2, long l3, long l4) {
    return method2(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }
  
  long method2(long l1, long l2, long l3, long l4) {
    return method3(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method3(long l1, long l2, long l3, long l4) {
    return method4(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method4(long l1, long l2, long l3, long l4) {
    return method5(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method5(long l1, long l2, long l3, long l4) {
    return method6(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method6(long l1, long l2, long l3, long l4) {
    return method7(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method7(long l1, long l2, long l3, long l4) {
    return method8(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method8(long l1, long l2, long l3, long l4) {
    return method9(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method9(long l1, long l2, long l3, long l4) {
    return method10(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method10(long l1, long l2, long l3, long l4) {
    return method11(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method11(long l1, long l2, long l3, long l4) {
    return method12(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method12(long l1, long l2, long l3, long l4) {
    return method13(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method13(long l1, long l2, long l3, long l4) {
    return method14(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method14(long l1, long l2, long l3, long l4) {
    return method15(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method15(long l1, long l2, long l3, long l4) {
    return method16(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method16(long l1, long l2, long l3, long l4) {
    return method17(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method17(long l1, long l2, long l3, long l4) {
    return method18(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method18(long l1, long l2, long l3, long l4) {
    return method19(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method19(long l1, long l2, long l3, long l4) {
    return method20(l1 + 1, l2 + 1, l3 + 1, l4 + 1) + l1 + l2 + l3 + l4;
  }

  long method20(long l1, long l2, long l3, long l4) {
    try {
      Thread.sleep(10000);
    } catch (Exception e) {
      e.printStackTrace();
    }
    return l1 + l2 + l3 + l4;
  }

  private void printMemory() {
    System.out.println("Total memory: " + Runtime.getRuntime().totalMemory());
  }
}