}

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }

    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i = 0; i < SIZE; i++) {
      aa.set(i, (double) COUNTDOWN);
    }
    Counter c1 = new Counter(aa);
    Counter c2 = new Counter(aa);
    Thread t1 = newStartedThread(c1);
    Thread t2 = newStartedThread(c2);
    awaitTermination(t1);
    awaitTermination(t2);
    assertEquals(SIZE * COUNTDOWN, c1.counts + c2.counts);

    private void setupMockComponentsWithCounter(final AtomicInteger counter) {
        setupMockComponents();

        // Override thumbnail manager with counter
        ThumbnailManager mockThumbnailManager = new ThumbnailManager() {
            @Override
            public int generate(ExecutorService executorService, boolean cleanup) {
                counter.incrementAndGet();
                // Return 0 to exit the loop

    for (int i = 0; i < 1000; i++) {
      AtomicInteger counter = new AtomicInteger();
      TrustedListenableFutureTask<Integer> task =
          TrustedListenableFutureTask.create(
              new Callable<Integer>() {
                @Override
                public Integer call() {
                  return counter.incrementAndGet();
                }
              });

      @SuppressWarnings("GoodTime") // reading system time without TimeSource
      String baseName = System.currentTimeMillis() + "-";

      for (int counter = 0; counter < TEMP_DIR_ATTEMPTS; counter++) {
        File tempDir = new File(baseDir, baseName + counter);
        if (tempDir.mkdir()) {
          return tempDir;
        }
      }
      throw new IllegalStateException(

    public void test_concurrent_stores() {
        // Test thread-safe implementation
        final AtomicLong counter = new AtomicLong(0);

        IndexUpdateCallback callback = new IndexUpdateCallback() {
            @Override
            public void store(DataStoreParams paramMap, Map<String, Object> dataMap) {
                counter.incrementAndGet();
            }

            @Override
            public long getDocumentSize() {

    Supplier<Integer> nonThreadSafe =
        new Supplier<Integer>() {
          int counter = 0;

          @Override
          public Integer get() {
            int nextValue = counter + 1;
            Thread.yield();
            counter = nextValue;
            return counter;
          }
        };

    int numThreads = 10;
    int iterations = 1000;

        }
        long size = spliterator.getExactSizeIfKnown();
        long[] counter = {0};
        spliterator.forEachRemaining(
            e -> {
              consumer.accept(e);
              counter[0]++;
            });
        if (size >= 0) {
          assertEquals(size, counter[0]);
        }
      }
    },
    ALTERNATE_ADVANCE_AND_SPLIT {
      @Override

        }
        long size = spliterator.getExactSizeIfKnown();
        long[] counter = {0};
        spliterator.forEachRemaining(
            e -> {
              consumer.accept(e);
              counter[0]++;
            });
        if (size >= 0) {
          assertEquals(size, counter[0]);
        }
      }
    },
    ALTERNATE_ADVANCE_AND_SPLIT {
      @Override

   * c, d, e]} with a partition size of 3 yields {@code [[a, b, c], [d, e]]} -- an outer list
   * containing two inner lists of three and two elements, all in the original order.
   *
   * <p>The outer list is unmodifiable, but reflects the latest state of the source list. The inner