ADDITIONAL SYSTEM INFORMATION :
MacOS 12.6 (21G115)
Java 19.0.1

A DESCRIPTION OF THE PROBLEM :
Waiting on CompletableFuture.get(timeout, timeunit) can take significantly longer than the provided timeout

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the provided test code. It schedules 5 jobs on the common execution pool. Each job inside creates another job and waits for its result like this with timeout. 4 Of the jobs take 1sec for execution and 2 sec as timeout. The 5th job takes 20sec for execution and 4 sec as timeout. So the get it's supposed to finish with TimeoutException after 4sec.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Code finishes after 4 seconds because of timeout expiration
ACTUAL -
Code takes 20sec to finish

---------- BEGIN SOURCE ----------
import java.util.ArrayList;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Supplier;

public class Main {
    public static void main(String[] args) throws Exception {
        ArrayList<CompletableFuture<Boolean>> futures = new ArrayList<>();
        for (int i = 0; i <= 1; i++) {
            futures.add(createJob(1000, 2000));
        }
        futures.add(createJob(20000, 4000));

        long start = System.currentTimeMillis();
        CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).get();
        long total = System.currentTimeMillis() - start;
        System.out.println("total: " + total);

        if (total > 5000) {
            throw new RuntimeException("total: " + total);
        }
    }

    public static CompletableFuture<Boolean> createJob(final int sleepTIme, int jobTimeout) {
        CompletableFuture<Boolean> job = CompletableFuture.supplyAsync(() -> {
            try {
                CompletableFuture<Boolean> finish = CompletableFuture.supplyAsync(() -> {
                    try {
                        Thread.sleep(sleepTIme);
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                    return false;
                });
                return finish.get(jobTimeout, TimeUnit.MILLISECONDS);
            } catch (InterruptedException e) {
                e.printStackTrace();
                Thread.currentThread().interrupt();
                throw new CompletionException(e);
            } catch (ExecutionException | TimeoutException e) {
                e.printStackTrace();
                throw new CompletionException(e);
            } catch (Throwable t) {
                t.printStackTrace();
            }
            return true;
        });

        return job.exceptionally(e -> false);
    }
}
---------- END SOURCE ----------

FREQUENCY : often