} finally {
                    endLatch.countDown();
                }
            });
        }

        // Start all threads
        startLatch.countDown();

        // Wait for completion
        assertTrue(endLatch.await(30, TimeUnit.SECONDS), "All threads should complete");
        executor.shutdown();

        // Then - All operations should succeed

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Basher test for {@link ConcurrentHashMultiset}: start a bunch of threads, have each of them do
 * operations at random. Each thread keeps track of the per-key deltas that it's directly
 * responsible for; after all threads have completed, we sum the per-key deltas and compare to the
 * existing multiset values.
 *
 * @author mike nonemacher
 */

@NullUnmarked

                        }
                    }
                }
            });
        }

        // Start all threads
        for (Thread thread : threads) {
            thread.start();
        }

        // Wait for all threads
        for (Thread thread : threads) {
            thread.join();
        }

        // Verify results
        assertTrue(exceptions.isEmpty());

                    throw new IllegalArgumentException("Invalid threads core multiplier value: '" + threadConfiguration
                            + "'. Value must be positive.");
                }

                int procs = Runtime.getRuntime().availableProcessors();
                int threads = (int) (coreMultiplier * procs);
                return threads == 0 ? 1 : threads;
            } else {

    @Nonnull
    Optional<Boolean> alsoMakeDependents();

    /**
     * Returns the number of threads used for parallel builds.
     *
     * @return an {@link Optional} containing the number of threads (or "1C" for one thread per CPU core), or empty if not specified
     */
    @Nonnull
    Optional<String> threads();

    /**
     * Returns the id of the build strategy to use.
     *

 * (method {@link #add}) are contended across threads, the set of variables may grow dynamically to
 * reduce contention. Method {@link #sum} (or, equivalently, {@link #longValue}) returns the current
 * total combined across the variables maintaining the sum.
 *
 * <p>This class is usually preferable to {@link AtomicLong} when multiple threads update a common

        .build()

    executor = newVirtualThreadPerTaskExecutor()

    // Capture non-deterministic but probable sysout warnings of pinned threads
    // https://docs.oracle.com/en/java/javase/21/core/virtual-threads.html
    System.setOut(PrintStream(capturedOut))
  }

  @AfterEach
  fun checkForPinning() {
    assertThat(capturedOut.toString()).isEmpty()
  }

 * (method {@link #add}) are contended across threads, the set of variables may grow dynamically to
 * reduce contention. Method {@link #sum} (or, equivalently, {@link #longValue}) returns the current
 * total combined across the variables maintaining the sum.
 *
 * <p>This class is usually preferable to {@link AtomicLong} when multiple threads update a common

    delay(millis);
    assertTrue(thread.isAlive());
  }

  /**
   * Checks that the threads do not terminate within the default millisecond delay of {@code
   * timeoutMillis()}.
   */
  void assertThreadsStayAlive(Thread... threads) throws InterruptedException {
    assertThreadsStayAlive(timeoutMillis(), threads);
  }

/**
 * Simple {@link ThreadFactory} implementation that ensures the corresponding threads have a meaningful name.
 */
public class BuildThreadFactory implements ThreadFactory {
    private final AtomicInteger id = new AtomicInteger();

    private static final String PREFIX = "BuilderThread";

    @Override
    public Thread newThread(Runnable r) {
        return new Thread(r, String.format("%s-%d", PREFIX, id.getAndIncrement()));
    }