--- jsr166/src/test/tck/LinkedBlockingQueueTest.java	2015/10/06 00:03:55	1.62
+++ jsr166/src/test/tck/LinkedBlockingQueueTest.java	2021/01/27 02:55:18	1.84
@@ -41,24 +41,32 @@ public class LinkedBlockingQueueTest ext
     }
 
     public static Test suite() {
+        class Implementation implements CollectionImplementation {
+            public Class<?> klazz() { return LinkedBlockingQueue.class; }
+            public Collection emptyCollection() { return new LinkedBlockingQueue(); }
+            public Object makeElement(int i) { return JSR166TestCase.itemFor(i); }
+            public boolean isConcurrent() { return true; }
+            public boolean permitsNulls() { return false; }
+        }
         return newTestSuite(LinkedBlockingQueueTest.class,
                             new Unbounded().testSuite(),
-                            new Bounded().testSuite());
+                            new Bounded().testSuite(),
+                            CollectionTest.testSuite(new Implementation()));
     }
 
     /**
      * Returns a new queue of given size containing consecutive
-     * Integers 0 ... n.
+     * Items 0 ... n - 1.
      */
-    private LinkedBlockingQueue<Integer> populatedQueue(int n) {
-        LinkedBlockingQueue<Integer> q =
-            new LinkedBlockingQueue<Integer>(n);
+    private static LinkedBlockingQueue<Item> populatedQueue(int n) {
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(n);
         assertTrue(q.isEmpty());
         for (int i = 0; i < n; i++)
-            assertTrue(q.offer(new Integer(i)));
+            mustOffer(q, i);
         assertFalse(q.isEmpty());
-        assertEquals(0, q.remainingCapacity());
-        assertEquals(n, q.size());
+        mustEqual(0, q.remainingCapacity());
+        mustEqual(n, q.size());
+        mustEqual(0, q.peek());
         return q;
     }
 
@@ -67,8 +75,8 @@ public class LinkedBlockingQueueTest ext
      * none given
      */
     public void testConstructor1() {
-        assertEquals(SIZE, new LinkedBlockingQueue(SIZE).remainingCapacity());
-        assertEquals(Integer.MAX_VALUE, new LinkedBlockingQueue().remainingCapacity());
+        mustEqual(SIZE, new LinkedBlockingQueue<Item>(SIZE).remainingCapacity());
+        mustEqual(Integer.MAX_VALUE, new LinkedBlockingQueue<Item>().remainingCapacity());
     }
 
     /**
@@ -76,7 +84,7 @@ public class LinkedBlockingQueueTest ext
      */
     public void testConstructor2() {
         try {
-            new LinkedBlockingQueue(0);
+            new LinkedBlockingQueue<Item>(0);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
     }
@@ -86,7 +94,7 @@ public class LinkedBlockingQueueTest ext
      */
     public void testConstructor3() {
         try {
-            new LinkedBlockingQueue(null);
+            new LinkedBlockingQueue<Item>(null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -95,9 +103,9 @@ public class LinkedBlockingQueueTest ext
      * Initializing from Collection of null elements throws NullPointerException
      */
     public void testConstructor4() {
-        Collection<Integer> elements = Arrays.asList(new Integer[SIZE]);
+        Collection<Item> elements = Arrays.asList(new Item[SIZE]);
         try {
-            new LinkedBlockingQueue(elements);
+            new LinkedBlockingQueue<Item>(elements);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -107,12 +115,11 @@ public class LinkedBlockingQueueTest ext
      * NullPointerException
      */
     public void testConstructor5() {
-        Integer[] ints = new Integer[SIZE];
-        for (int i = 0; i < SIZE - 1; ++i)
-            ints[i] = new Integer(i);
-        Collection<Integer> elements = Arrays.asList(ints);
+        Item[] items = new Item[2];
+        items[0] = zero;
+        Collection<Item> elements = Arrays.asList(items);
         try {
-            new LinkedBlockingQueue(elements);
+            new LinkedBlockingQueue<Item>(elements);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -121,26 +128,24 @@ public class LinkedBlockingQueueTest ext
      * Queue contains all elements of collection used to initialize
      */
     public void testConstructor6() {
-        Integer[] ints = new Integer[SIZE];
-        for (int i = 0; i < SIZE; ++i)
-            ints[i] = new Integer(i);
-        LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
+        Item[] items = defaultItems;
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(Arrays.asList(items));
         for (int i = 0; i < SIZE; ++i)
-            assertEquals(ints[i], q.poll());
+            mustEqual(items[i], q.poll());
     }
 
     /**
      * Queue transitions from empty to full when elements added
      */
     public void testEmptyFull() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(2);
         assertTrue(q.isEmpty());
-        assertEquals("should have room for 2", 2, q.remainingCapacity());
+        mustEqual(2, q.remainingCapacity());
         q.add(one);
         assertFalse(q.isEmpty());
         q.add(two);
         assertFalse(q.isEmpty());
-        assertEquals(0, q.remainingCapacity());
+        mustEqual(0, q.remainingCapacity());
         assertFalse(q.offer(three));
     }
 
@@ -148,16 +153,16 @@ public class LinkedBlockingQueueTest ext
      * remainingCapacity decreases on add, increases on remove
      */
     public void testRemainingCapacity() {
-        BlockingQueue q = populatedQueue(SIZE);
+        BlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.remainingCapacity());
-            assertEquals(SIZE, q.size() + q.remainingCapacity());
-            assertEquals(i, q.remove());
+            mustEqual(i, q.remainingCapacity());
+            mustEqual(SIZE, q.size() + q.remainingCapacity());
+            mustEqual(i, q.remove());
         }
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(SIZE - i, q.remainingCapacity());
-            assertEquals(SIZE, q.size() + q.remainingCapacity());
-            assertTrue(q.add(i));
+            mustEqual(SIZE - i, q.remainingCapacity());
+            mustEqual(SIZE, q.size() + q.remainingCapacity());
+            mustAdd(q, i);
         }
     }
 
@@ -165,7 +170,7 @@ public class LinkedBlockingQueueTest ext
      * Offer succeeds if not full; fails if full
      */
     public void testOffer() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(1);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(1);
         assertTrue(q.offer(zero));
         assertFalse(q.offer(one));
     }
@@ -174,12 +179,12 @@ public class LinkedBlockingQueueTest ext
      * add succeeds if not full; throws IllegalStateException if full
      */
     public void testAdd() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE);
         for (int i = 0; i < SIZE; ++i)
-            assertTrue(q.add(new Integer(i)));
-        assertEquals(0, q.remainingCapacity());
+            mustAdd(q, i);
+        mustEqual(0, q.remainingCapacity());
         try {
-            q.add(new Integer(SIZE));
+            q.add(new Item(SIZE));
             shouldThrow();
         } catch (IllegalStateException success) {}
     }
@@ -188,7 +193,7 @@ public class LinkedBlockingQueueTest ext
      * addAll(this) throws IllegalArgumentException
      */
     public void testAddAllSelf() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         try {
             q.addAll(q);
             shouldThrow();
@@ -200,11 +205,9 @@ public class LinkedBlockingQueueTest ext
      * possibly adding some elements
      */
     public void testAddAll3() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-        Integer[] ints = new Integer[SIZE];
-        for (int i = 0; i < SIZE - 1; ++i)
-            ints[i] = new Integer(i);
-        Collection<Integer> elements = Arrays.asList(ints);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE);
+        Item[] items = new Item[2]; items[0] = zero;
+        Collection<Item> elements = Arrays.asList(items);
         try {
             q.addAll(elements);
             shouldThrow();
@@ -215,11 +218,9 @@ public class LinkedBlockingQueueTest ext
      * addAll throws IllegalStateException if not enough room
      */
     public void testAddAll4() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE - 1);
-        Integer[] ints = new Integer[SIZE];
-        for (int i = 0; i < SIZE; ++i)
-            ints[i] = new Integer(i);
-        Collection<Integer> elements = Arrays.asList(ints);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE - 1);
+        Item[] items = defaultItems;
+        Collection<Item> elements = Arrays.asList(items);
         try {
             q.addAll(elements);
             shouldThrow();
@@ -230,64 +231,62 @@ public class LinkedBlockingQueueTest ext
      * Queue contains all elements, in traversal order, of successful addAll
      */
     public void testAddAll5() {
-        Integer[] empty = new Integer[0];
-        Integer[] ints = new Integer[SIZE];
-        for (int i = 0; i < SIZE; ++i)
-            ints[i] = new Integer(i);
-        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
+        Item[] empty = new Item[0];
+        Item[] items = defaultItems;
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE);
         assertFalse(q.addAll(Arrays.asList(empty)));
-        assertTrue(q.addAll(Arrays.asList(ints)));
+        assertTrue(q.addAll(Arrays.asList(items)));
         for (int i = 0; i < SIZE; ++i)
-            assertEquals(ints[i], q.poll());
+            mustEqual(items[i], q.poll());
     }
 
     /**
      * all elements successfully put are contained
      */
     public void testPut() throws InterruptedException {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            Integer x = new Integer(i);
+            Item x = itemFor(i);
             q.put(x);
-            assertTrue(q.contains(x));
+            mustContain(q, x);
         }
-        assertEquals(0, q.remainingCapacity());
+        mustEqual(0, q.remainingCapacity());
     }
 
     /**
      * put blocks interruptibly if full
      */
     public void testBlockingPut() throws InterruptedException {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(SIZE);
         final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
         Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
                 for (int i = 0; i < SIZE; ++i)
-                    q.put(i);
-                assertEquals(SIZE, q.size());
-                assertEquals(0, q.remainingCapacity());
+                    q.put(itemFor(i));
+                mustEqual(SIZE, q.size());
+                mustEqual(0, q.remainingCapacity());
 
                 Thread.currentThread().interrupt();
                 try {
-                    q.put(99);
+                    q.put(ninetynine);
                     shouldThrow();
                 } catch (InterruptedException success) {}
                 assertFalse(Thread.interrupted());
 
                 pleaseInterrupt.countDown();
                 try {
-                    q.put(99);
+                    q.put(ninetynine);
                     shouldThrow();
                 } catch (InterruptedException success) {}
                 assertFalse(Thread.interrupted());
             }});
 
         await(pleaseInterrupt);
-        assertThreadStaysAlive(t);
+        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
         t.interrupt();
         awaitTermination(t);
-        assertEquals(SIZE, q.size());
-        assertEquals(0, q.remainingCapacity());
+        mustEqual(SIZE, q.size());
+        mustEqual(0, q.remainingCapacity());
     }
 
     /**
@@ -295,57 +294,74 @@ public class LinkedBlockingQueueTest ext
      */
     public void testPutWithTake() throws InterruptedException {
         final int capacity = 2;
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(2);
         final CountDownLatch pleaseTake = new CountDownLatch(1);
         final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
         Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
                 for (int i = 0; i < capacity; i++)
-                    q.put(i);
+                    q.put(itemFor(i));
                 pleaseTake.countDown();
-                q.put(86);
+                q.put(eightysix);
+
+                Thread.currentThread().interrupt();
+                try {
+                    q.put(ninetynine);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
 
                 pleaseInterrupt.countDown();
                 try {
-                    q.put(99);
+                    q.put(ninetynine);
                     shouldThrow();
                 } catch (InterruptedException success) {}
                 assertFalse(Thread.interrupted());
             }});
 
         await(pleaseTake);
-        assertEquals(0, q.remainingCapacity());
-        assertEquals(0, q.take());
+        mustEqual(0, q.remainingCapacity());
+        mustEqual(0, q.take());
 
         await(pleaseInterrupt);
-        assertThreadStaysAlive(t);
+        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
         t.interrupt();
         awaitTermination(t);
-        assertEquals(0, q.remainingCapacity());
+        mustEqual(0, q.remainingCapacity());
     }
 
     /**
      * timed offer times out if full and elements not taken
      */
     public void testTimedOffer() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(2);
         final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
         Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                q.put(new Object());
-                q.put(new Object());
+                q.put(zero);
+                q.put(one);
                 long startTime = System.nanoTime();
-                assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS));
+
+                assertFalse(q.offer(two, timeoutMillis(), MILLISECONDS));
                 assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
+
+                Thread.currentThread().interrupt();
+                try {
+                    q.offer(three, randomTimeout(), randomTimeUnit());
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+
                 pleaseInterrupt.countDown();
                 try {
-                    q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
+                    q.offer(two, LONGER_DELAY_MS, MILLISECONDS);
                     shouldThrow();
                 } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
             }});
 
         await(pleaseInterrupt);
-        assertThreadStaysAlive(t);
+        if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
         t.interrupt();
         awaitTermination(t);
     }
@@ -354,9 +370,9 @@ public class LinkedBlockingQueueTest ext
      * take retrieves elements in FIFO order
      */
     public void testTake() throws InterruptedException {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.take());
+            mustEqual(i, q.take());
         }
     }
 
@@ -364,13 +380,11 @@ public class LinkedBlockingQueueTest ext
      * Take removes existing elements until empty, then blocks interruptibly
      */
     public void testBlockingTake() throws InterruptedException {
-        final BlockingQueue q = populatedQueue(SIZE);
+        final BlockingQueue<Item> q = populatedQueue(SIZE);
         final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
         Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                for (int i = 0; i < SIZE; ++i) {
-                    assertEquals(i, q.take());
-                }
+                for (int i = 0; i < SIZE; i++) mustEqual(i, q.take());
 
                 Thread.currentThread().interrupt();
                 try {
@@ -388,7 +402,7 @@ public class LinkedBlockingQueueTest ext
             }});
 
         await(pleaseInterrupt);
-        assertThreadStaysAlive(t);
+        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
         t.interrupt();
         awaitTermination(t);
     }
@@ -397,9 +411,9 @@ public class LinkedBlockingQueueTest ext
      * poll succeeds unless empty
      */
     public void testPoll() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.poll());
+            mustEqual(i, q.poll());
         }
         assertNull(q.poll());
     }
@@ -408,9 +422,9 @@ public class LinkedBlockingQueueTest ext
      * timed poll with zero timeout succeeds when non-empty, else times out
      */
     public void testTimedPoll0() throws InterruptedException {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.poll(0, MILLISECONDS));
+            mustEqual(i, q.poll(0, MILLISECONDS));
         }
         assertNull(q.poll(0, MILLISECONDS));
     }
@@ -419,10 +433,10 @@ public class LinkedBlockingQueueTest ext
      * timed poll with nonzero timeout succeeds when non-empty, else times out
      */
     public void testTimedPoll() throws InterruptedException {
-        LinkedBlockingQueue<Integer> q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
             long startTime = System.nanoTime();
-            assertEquals(i, (int) q.poll(LONG_DELAY_MS, MILLISECONDS));
+            mustEqual(i, q.poll(LONG_DELAY_MS, MILLISECONDS));
             assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
         }
         long startTime = System.nanoTime();
@@ -436,25 +450,30 @@ public class LinkedBlockingQueueTest ext
      * returning timeout status
      */
     public void testInterruptedTimedPoll() throws InterruptedException {
-        final BlockingQueue<Integer> q = populatedQueue(SIZE);
-        final CountDownLatch aboutToWait = new CountDownLatch(1);
+        final BlockingQueue<Item> q = populatedQueue(SIZE);
+        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
         Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                long startTime = System.nanoTime();
-                for (int i = 0; i < SIZE; ++i) {
-                    assertEquals(i, (int) q.poll(LONG_DELAY_MS, MILLISECONDS));
-                }
-                aboutToWait.countDown();
+                for (int i = 0; i < SIZE; i++)
+                    mustEqual(i, q.poll(LONG_DELAY_MS, MILLISECONDS));
+
+                Thread.currentThread().interrupt();
                 try {
-                    q.poll(LONG_DELAY_MS, MILLISECONDS);
+                    q.poll(randomTimeout(), randomTimeUnit());
                     shouldThrow();
-                } catch (InterruptedException success) {
-                    assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
-                }
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+
+                pleaseInterrupt.countDown();
+                try {
+                    q.poll(LONGER_DELAY_MS, MILLISECONDS);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
             }});
 
-        await(aboutToWait);
-        waitForThreadToEnterWaitState(t, LONG_DELAY_MS);
+        await(pleaseInterrupt);
+        if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
         t.interrupt();
         awaitTermination(t);
         checkEmpty(q);
@@ -464,10 +483,10 @@ public class LinkedBlockingQueueTest ext
      * peek returns next element, or null if empty
      */
     public void testPeek() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.peek());
-            assertEquals(i, q.poll());
+            mustEqual(i, q.peek());
+            mustEqual(i, q.poll());
             assertTrue(q.peek() == null ||
                        !q.peek().equals(i));
         }
@@ -478,10 +497,10 @@ public class LinkedBlockingQueueTest ext
      * element returns next element, or throws NSEE if empty
      */
     public void testElement() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.element());
-            assertEquals(i, q.poll());
+            mustEqual(i, q.element());
+            mustEqual(i, q.poll());
         }
         try {
             q.element();
@@ -493,9 +512,9 @@ public class LinkedBlockingQueueTest ext
      * remove removes next element, or throws NSEE if empty
      */
     public void testRemove() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.remove());
+            mustEqual(i, q.remove());
         }
         try {
             q.remove();
@@ -507,12 +526,12 @@ public class LinkedBlockingQueueTest ext
      * An add following remove(x) succeeds
      */
     public void testRemoveElementAndAdd() throws InterruptedException {
-        LinkedBlockingQueue q = new LinkedBlockingQueue();
-        assertTrue(q.add(new Integer(1)));
-        assertTrue(q.add(new Integer(2)));
-        assertTrue(q.remove(new Integer(1)));
-        assertTrue(q.remove(new Integer(2)));
-        assertTrue(q.add(new Integer(3)));
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>();
+        assertTrue(q.add(one));
+        assertTrue(q.add(two));
+        mustRemove(q, one);
+        mustRemove(q, two);
+        mustAdd(q, three);
         assertNotNull(q.take());
     }
 
@@ -520,11 +539,11 @@ public class LinkedBlockingQueueTest ext
      * contains(x) reports true when elements added but not yet removed
      */
     public void testContains() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertTrue(q.contains(new Integer(i)));
+            mustContain(q, i);
             q.poll();
-            assertFalse(q.contains(new Integer(i)));
+            mustNotContain(q, i);
         }
     }
 
@@ -532,11 +551,11 @@ public class LinkedBlockingQueueTest ext
      * clear removes all elements
      */
     public void testClear() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         q.clear();
         assertTrue(q.isEmpty());
-        assertEquals(0, q.size());
-        assertEquals(SIZE, q.remainingCapacity());
+        mustEqual(0, q.size());
+        mustEqual(SIZE, q.remainingCapacity());
         q.add(one);
         assertFalse(q.isEmpty());
         assertTrue(q.contains(one));
@@ -548,12 +567,12 @@ public class LinkedBlockingQueueTest ext
      * containsAll(c) is true when c contains a subset of elements
      */
     public void testContainsAll() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        LinkedBlockingQueue p = new LinkedBlockingQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> p = new LinkedBlockingQueue<>(SIZE);
         for (int i = 0; i < SIZE; ++i) {
             assertTrue(q.containsAll(p));
             assertFalse(p.containsAll(q));
-            p.add(new Integer(i));
+            mustAdd(p, i);
         }
         assertTrue(p.containsAll(q));
     }
@@ -562,8 +581,8 @@ public class LinkedBlockingQueueTest ext
      * retainAll(c) retains only those elements of c and reports true if changed
      */
     public void testRetainAll() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        LinkedBlockingQueue p = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> p = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
             boolean changed = q.retainAll(p);
             if (i == 0)
@@ -572,7 +591,7 @@ public class LinkedBlockingQueueTest ext
                 assertTrue(changed);
 
             assertTrue(q.containsAll(p));
-            assertEquals(SIZE - i, q.size());
+            mustEqual(SIZE - i, q.size());
             p.remove();
         }
     }
@@ -582,13 +601,12 @@ public class LinkedBlockingQueueTest ext
      */
     public void testRemoveAll() {
         for (int i = 1; i < SIZE; ++i) {
-            LinkedBlockingQueue q = populatedQueue(SIZE);
-            LinkedBlockingQueue p = populatedQueue(i);
+            LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+            LinkedBlockingQueue<Item> p = populatedQueue(i);
             assertTrue(q.removeAll(p));
-            assertEquals(SIZE - i, q.size());
+            mustEqual(SIZE - i, q.size());
             for (int j = 0; j < i; ++j) {
-                Integer x = (Integer)(p.remove());
-                assertFalse(q.contains(x));
+                mustNotContain(q, p.remove());
             }
         }
     }
@@ -597,29 +615,33 @@ public class LinkedBlockingQueueTest ext
      * toArray contains all elements in FIFO order
      */
     public void testToArray() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        Object[] o = q.toArray();
-        for (int i = 0; i < o.length; i++)
-            assertSame(o[i], q.poll());
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        Object[] a = q.toArray();
+        assertSame(Object[].class, a.getClass());
+        for (Object o : a)
+            assertSame(o, q.poll());
+        assertTrue(q.isEmpty());
     }
 
     /**
      * toArray(a) contains all elements in FIFO order
      */
     public void testToArray2() throws InterruptedException {
-        LinkedBlockingQueue<Integer> q = populatedQueue(SIZE);
-        Integer[] ints = new Integer[SIZE];
-        Integer[] array = q.toArray(ints);
-        assertSame(ints, array);
-        for (int i = 0; i < ints.length; i++)
-            assertSame(ints[i], q.poll());
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        Item[] items = new Item[SIZE];
+        Item[] array = q.toArray(items);
+        assertSame(items, array);
+        for (Item o : items)
+            assertSame(o, q.poll());
+        assertTrue(q.isEmpty());
     }
 
     /**
      * toArray(incompatible array type) throws ArrayStoreException
      */
-    public void testToArray1_BadArg() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+    @SuppressWarnings("CollectionToArraySafeParameter")
+    public void testToArray_incompatibleArrayType() {
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         try {
             q.toArray(new String[10]);
             shouldThrow();
@@ -630,18 +652,18 @@ public class LinkedBlockingQueueTest ext
      * iterator iterates through all elements
      */
     public void testIterator() throws InterruptedException {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        Iterator it = q.iterator();
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        Iterator<? extends Item> it = q.iterator();
         int i;
         for (i = 0; it.hasNext(); i++)
-            assertTrue(q.contains(it.next()));
-        assertEquals(i, SIZE);
+            mustContain(q, it.next());
+        mustEqual(i, SIZE);
         assertIteratorExhausted(it);
 
         it = q.iterator();
         for (i = 0; it.hasNext(); i++)
-            assertEquals(it.next(), q.take());
-        assertEquals(i, SIZE);
+            mustEqual(it.next(), q.take());
+        mustEqual(i, SIZE);
         assertIteratorExhausted(it);
     }
 
@@ -649,19 +671,19 @@ public class LinkedBlockingQueueTest ext
      * iterator of empty collection has no elements
      */
     public void testEmptyIterator() {
-        assertIteratorExhausted(new LinkedBlockingQueue().iterator());
+        assertIteratorExhausted(new LinkedBlockingQueue<Item>().iterator());
     }
 
     /**
      * iterator.remove removes current element
      */
     public void testIteratorRemove() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(3);
         q.add(two);
         q.add(one);
         q.add(three);
 
-        Iterator it = q.iterator();
+        Iterator<? extends Item> it = q.iterator();
         it.next();
         it.remove();
 
@@ -675,38 +697,38 @@ public class LinkedBlockingQueueTest ext
      * iterator ordering is FIFO
      */
     public void testIteratorOrdering() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(3);
         q.add(one);
         q.add(two);
         q.add(three);
-        assertEquals(0, q.remainingCapacity());
+        mustEqual(0, q.remainingCapacity());
         int k = 0;
-        for (Iterator it = q.iterator(); it.hasNext();) {
-            assertEquals(++k, it.next());
+        for (Iterator<? extends Item> it = q.iterator(); it.hasNext();) {
+            mustEqual(++k, it.next());
         }
-        assertEquals(3, k);
+        mustEqual(3, k);
     }
 
     /**
      * Modifications do not cause iterators to fail
      */
     public void testWeaklyConsistentIteration() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(3);
         q.add(one);
         q.add(two);
         q.add(three);
-        for (Iterator it = q.iterator(); it.hasNext();) {
+        for (Iterator<? extends Item> it = q.iterator(); it.hasNext();) {
             q.remove();
             it.next();
         }
-        assertEquals(0, q.size());
+        mustEqual(0, q.size());
     }
 
     /**
      * toString contains toStrings of elements
      */
     public void testToString() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         String s = q.toString();
         for (int i = 0; i < SIZE; ++i) {
             assertTrue(s.contains(String.valueOf(i)));
@@ -717,7 +739,7 @@ public class LinkedBlockingQueueTest ext
      * offer transfers elements across Executor tasks
      */
     public void testOfferInExecutor() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(2);
         q.add(one);
         q.add(two);
         final CheckedBarrier threadsStarted = new CheckedBarrier(2);
@@ -728,7 +750,7 @@ public class LinkedBlockingQueueTest ext
                     assertFalse(q.offer(three));
                     threadsStarted.await();
                     assertTrue(q.offer(three, LONG_DELAY_MS, MILLISECONDS));
-                    assertEquals(0, q.remainingCapacity());
+                    mustEqual(0, q.remainingCapacity());
                 }});
 
             executor.execute(new CheckedRunnable() {
@@ -743,7 +765,7 @@ public class LinkedBlockingQueueTest ext
      * timed poll retrieves elements across Executor threads
      */
     public void testPollInExecutor() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        final LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>(2);
         final CheckedBarrier threadsStarted = new CheckedBarrier(2);
         final ExecutorService executor = Executors.newFixedThreadPool(2);
         try (PoolCleaner cleaner = cleaner(executor)) {
@@ -764,19 +786,19 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * A deserialized serialized queue has same elements in same order
+     * A deserialized/reserialized queue has same elements in same order
      */
     public void testSerialization() throws Exception {
-        Queue x = populatedQueue(SIZE);
-        Queue y = serialClone(x);
+        Queue<Item> x = populatedQueue(SIZE);
+        Queue<Item> y = serialClone(x);
 
         assertNotSame(x, y);
-        assertEquals(x.size(), y.size());
-        assertEquals(x.toString(), y.toString());
+        mustEqual(x.size(), y.size());
+        mustEqual(x.toString(), y.toString());
         assertTrue(Arrays.equals(x.toArray(), y.toArray()));
         while (!x.isEmpty()) {
             assertFalse(y.isEmpty());
-            assertEquals(x.remove(), y.remove());
+            mustEqual(x.remove(), y.remove());
         }
         assertTrue(y.isEmpty());
     }
@@ -785,42 +807,42 @@ public class LinkedBlockingQueueTest ext
      * drainTo(c) empties queue into another collection c
      */
     public void testDrainTo() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        ArrayList l = new ArrayList();
+        LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
+        ArrayList<Item> l = new ArrayList<>();
         q.drainTo(l);
-        assertEquals(0, q.size());
-        assertEquals(SIZE, l.size());
+        mustEqual(0, q.size());
+        mustEqual(SIZE, l.size());
         for (int i = 0; i < SIZE; ++i)
-            assertEquals(l.get(i), new Integer(i));
+            mustEqual(l.get(i), i);
         q.add(zero);
         q.add(one);
         assertFalse(q.isEmpty());
-        assertTrue(q.contains(zero));
-        assertTrue(q.contains(one));
+        mustContain(q, zero);
+        mustContain(q, one);
         l.clear();
         q.drainTo(l);
-        assertEquals(0, q.size());
-        assertEquals(2, l.size());
+        mustEqual(0, q.size());
+        mustEqual(2, l.size());
         for (int i = 0; i < 2; ++i)
-            assertEquals(l.get(i), new Integer(i));
+            mustEqual(l.get(i), i);
     }
 
     /**
      * drainTo empties full queue, unblocking a waiting put.
      */
     public void testDrainToWithActivePut() throws InterruptedException {
-        final LinkedBlockingQueue q = populatedQueue(SIZE);
+        final LinkedBlockingQueue<Item> q = populatedQueue(SIZE);
         Thread t = new Thread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                q.put(new Integer(SIZE + 1));
+                q.put(new Item(SIZE + 1));
             }});
 
         t.start();
-        ArrayList l = new ArrayList();
+        ArrayList<Item> l = new ArrayList<>();
         q.drainTo(l);
         assertTrue(l.size() >= SIZE);
         for (int i = 0; i < SIZE; ++i)
-            assertEquals(l.get(i), new Integer(i));
+            mustEqual(l.get(i), i);
         t.join();
         assertTrue(q.size() + l.size() >= SIZE);
     }
@@ -829,17 +851,17 @@ public class LinkedBlockingQueueTest ext
      * drainTo(c, n) empties first min(n, size) elements of queue into c
      */
     public void testDrainToN() {
-        LinkedBlockingQueue q = new LinkedBlockingQueue();
+        LinkedBlockingQueue<Item> q = new LinkedBlockingQueue<>();
         for (int i = 0; i < SIZE + 2; ++i) {
             for (int j = 0; j < SIZE; j++)
-                assertTrue(q.offer(new Integer(j)));
-            ArrayList l = new ArrayList();
+                mustOffer(q, j);
+            ArrayList<Item> l = new ArrayList<>();
             q.drainTo(l, i);
             int k = (i < SIZE) ? i : SIZE;
-            assertEquals(k, l.size());
-            assertEquals(SIZE - k, q.size());
+            mustEqual(k, l.size());
+            mustEqual(SIZE - k, q.size());
             for (int j = 0; j < k; ++j)
-                assertEquals(l.get(j), new Integer(j));
+                mustEqual(l.get(j), j);
             do {} while (q.poll() != null);
         }
     }
@@ -849,7 +871,7 @@ public class LinkedBlockingQueueTest ext
      */
     public void testNeverContainsNull() {
         Collection<?>[] qs = {
-            new LinkedBlockingQueue<Object>(),
+            new LinkedBlockingQueue<>(),
             populatedQueue(2),
         };