ADDITIONAL SYSTEM INFORMATION :
openjdk version "21.0.1" 2023-10-17 LTS
OpenJDK Runtime Environment Temurin-21.0.1+12 (build 21.0.1+12-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.1+12 (build 21.0.1+12-LTS, mixed mode, sharing)

A DESCRIPTION OF THE PROBLEM :
Executors.newVirtualThreadPerTaskExecutor didn't name the threads it created by default, which caused great inconvenience to logging and debugging. Moreover, it does not provide a method for customizing thread factory.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. create an executor by Executors.newVirtualThreadPerTaskExecutor()
2. submit tasks and print thread names


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
named virtual threads, for example:

Thread: (0) virtual-0
Thread: (1) virtual-1
Thread: (2) virtual-2
Thread: (3) virtual-4
Thread: (4) virtual-3
Thread: (6) virtual-7
Thread: (7) virtual-9
Thread: (9) virtual-8
Thread: (5) virtual-5
Thread: (8) virtual-6
ACTUAL -
Thread: (0)
Thread: (1)
Thread: (2)
Thread: (3)
Thread: (4)
Thread: (6)
Thread: (7)
Thread: (9)
Thread: (5)
Thread: (8)

---------- BEGIN SOURCE ----------
import java.time.Duration;
import java.util.ArrayList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class Main {
    public static void main(String[] args) {
        try (final var pool = Executors.newVirtualThreadPerTaskExecutor()) {
            final var futures = new ArrayList<Future<Integer>>();
            for (int i = 0; i < 10; i += 1) {
                final var id = i;
                final var future = pool.submit(() -> {
                    try {
                        Thread.sleep(Duration.ofSeconds(4));
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                    System.out.printf("Thread: (%d) %s%n", id, Thread.currentThread().getName());
                    return 0;
                });
                futures.add(future);
            }
            futures.forEach(future -> {
                try {
                    future.get();
                } catch (InterruptedException | ExecutionException e) {
                    throw new RuntimeException(e);
                }
            });
        }
    }
}

---------- END SOURCE ----------

FREQUENCY : always