qr1->StartCounting(&counter, 100);
  TF_ASSERT_OK(coord.RegisterRunner(std::move(qr1)));

  std::unique_ptr<MockQueueRunner> qr2(new MockQueueRunner(&coord));
  qr2->StartCounting(&counter, 100);
  TF_ASSERT_OK(coord.RegisterRunner(std::move(qr2)));

  // Wait until the counting has started
  while (counter.load() == 0)
    ;
  TF_EXPECT_OK(coord.RequestStop());