@Test
  public void testNewDiskId() {
    deleteFiles();
    region = DiskRegionHelperFactory.getAsyncPersistOnlyRegion(cache, diskProps);

    TestNewDiskId newDiskId = new TestNewDiskId();
    Thread thread1 = new Thread(newDiskId);
    Thread thread2 = new Thread(newDiskId);
    Thread thread3 = new Thread(newDiskId);
    Thread thread4 = new Thread(newDiskId);
    Thread thread5 = new Thread(newDiskId);

    thread1.setDaemon(true);
    thread2.setDaemon(true);
    thread3.setDaemon(true);
    thread4.setDaemon(true);
    thread5.setDaemon(true);

    thread1.start();
    thread2.start();
    thread3.start();
    thread4.start();
    thread5.start();

    ThreadUtils.join(thread1, 30 * 1000);
    ThreadUtils.join(thread2, 30 * 1000);
    ThreadUtils.join(thread3, 30 * 1000);
    ThreadUtils.join(thread4, 30 * 1000);
    ThreadUtils.join(thread5, 30 * 1000);

    if (keyIds.size() != 50000) {
      fail("Size not equal to 5000 as expected but is " + keyIds.size());
    }

    closeDown();
  }
Testing methods for SimpleDiskRegion.java api's

@since GemFire 5.1
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/SimpleDiskRegionJUnitTest.java