public void testConcurrentWritesAndIteration() throws Exception { final Cache<String, Object> cache1 = cache(0, "atomic"); assertSize(cache1, 0); final Map<String, String> map = createAtomicMap(cache1, "testConcurrentWritesAndIteration", true); assertSize(map, 0); runConcurrently(1, TimeUnit.MINUTES, () -> { Map<String, String> map1 = createAtomicMap(cache1, "testConcurrentWritesAndIteration", true); for (int i = 0; i < 250; i++) { map1.put("key-" + i, "value-" + i); } }, () -> { Map<String, String> map12 = createAtomicMap(cache1, "testConcurrentWritesAndIteration", true); for (int i = 0; i < 250; i++) { map12.keySet(); } }); }