--- jsr166/src/test/tck/LinkedBlockingQueueTest.java	2010/08/25 01:44:48	1.27
+++ jsr166/src/test/tck/LinkedBlockingQueueTest.java	2015/01/17 22:55:06	1.57
@@ -1,34 +1,58 @@
 /*
  * Written by Doug Lea with assistance from members of JCP JSR-166
  * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
+ * http://creativecommons.org/publicdomain/zero/1.0/
  * Other contributors include Andrew Wright, Jeffrey Hayes,
  * Pat Fisher, Mike Judd.
  */
 
-import junit.framework.*;
-import java.util.*;
-import java.util.concurrent.*;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import java.io.*;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import junit.framework.Test;
 
 public class LinkedBlockingQueueTest extends JSR166TestCase {
 
+    public static class Unbounded extends BlockingQueueTest {
+        protected BlockingQueue emptyCollection() {
+            return new LinkedBlockingQueue();
+        }
+    }
+
+    public static class Bounded extends BlockingQueueTest {
+        protected BlockingQueue emptyCollection() {
+            return new LinkedBlockingQueue(SIZE);
+        }
+    }
+
     public static void main(String[] args) {
         junit.textui.TestRunner.run(suite());
     }
 
     public static Test suite() {
-        return new TestSuite(LinkedBlockingQueueTest.class);
+        return newTestSuite(LinkedBlockingQueueTest.class,
+                            new Unbounded().testSuite(),
+                            new Bounded().testSuite());
     }
 
-
     /**
-     * Create a queue of given size containing consecutive
+     * Returns a new queue of given size containing consecutive
      * Integers 0 ... n.
      */
-    private LinkedBlockingQueue populatedQueue(int n) {
-        LinkedBlockingQueue q = new LinkedBlockingQueue(n);
+    private LinkedBlockingQueue<Integer> populatedQueue(int n) {
+        LinkedBlockingQueue<Integer> q =
+            new LinkedBlockingQueue<Integer>(n);
         assertTrue(q.isEmpty());
         for (int i = 0; i < n; i++)
             assertTrue(q.offer(new Integer(i)));
@@ -48,45 +72,47 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * Constructor throws IAE if capacity argument nonpositive
+     * Constructor throws IllegalArgumentException if capacity argument nonpositive
      */
     public void testConstructor2() {
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(0);
+            new LinkedBlockingQueue(0);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
     }
 
     /**
-     * Initializing from null Collection throws NPE
+     * Initializing from null Collection throws NullPointerException
      */
     public void testConstructor3() {
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(null);
+            new LinkedBlockingQueue(null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
 
     /**
-     * Initializing from Collection of null elements throws NPE
+     * Initializing from Collection of null elements throws NullPointerException
      */
     public void testConstructor4() {
+        Collection<Integer> elements = Arrays.asList(new Integer[SIZE]);
         try {
-            Integer[] ints = new Integer[SIZE];
-            LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
+            new LinkedBlockingQueue(elements);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
 
     /**
-     * Initializing from Collection with some null elements throws NPE
+     * Initializing from Collection with some null elements throws
+     * 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);
         try {
-            Integer[] ints = new Integer[SIZE];
-            for (int i = 0; i < SIZE-1; ++i)
-                ints[i] = new Integer(i);
-            LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
+            new LinkedBlockingQueue(elements);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -136,28 +162,6 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * offer(null) throws NPE
-     */
-    public void testOfferNull() {
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            q.offer(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
-     * add(null) throws NPE
-     */
-    public void testAddNull() {
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            q.add(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
      * Offer succeeds if not full; fails if full
      */
     public void testOffer() {
@@ -167,79 +171,57 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * add succeeds if not full; throws ISE if full
+     * add succeeds if not full; throws IllegalStateException if full
      */
     public void testAdd() {
+        LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i)
+            assertTrue(q.add(new Integer(i)));
+        assertEquals(0, q.remainingCapacity());
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-            for (int i = 0; i < SIZE; ++i) {
-                assertTrue(q.add(new Integer(i)));
-            }
-            assertEquals(0, q.remainingCapacity());
             q.add(new Integer(SIZE));
             shouldThrow();
         } catch (IllegalStateException success) {}
     }
 
     /**
-     * addAll(null) throws NPE
-     */
-    public void testAddAll1() {
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            q.addAll(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
-     * addAll(this) throws IAE
+     * addAll(this) throws IllegalArgumentException
      */
     public void testAddAllSelf() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
         try {
-            LinkedBlockingQueue q = populatedQueue(SIZE);
             q.addAll(q);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
     }
 
     /**
-     * addAll of a collection with null elements throws NPE
-     */
-    public void testAddAll2() {
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-            Integer[] ints = new Integer[SIZE];
-            q.addAll(Arrays.asList(ints));
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
      * addAll of a collection with any null elements throws NPE after
      * 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);
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-            Integer[] ints = new Integer[SIZE];
-            for (int i = 0; i < SIZE-1; ++i)
-                ints[i] = new Integer(i);
-            q.addAll(Arrays.asList(ints));
+            q.addAll(elements);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
 
     /**
-     * addAll throws ISE if not enough room
+     * 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);
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            Integer[] ints = new Integer[SIZE];
-            for (int i = 0; i < SIZE; ++i)
-                ints[i] = new Integer(i);
-            q.addAll(Arrays.asList(ints));
+            q.addAll(elements);
             shouldThrow();
         } catch (IllegalStateException success) {}
     }
@@ -260,25 +242,14 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * put(null) throws NPE
-     */
-     public void testPutNull() throws InterruptedException {
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-            q.put(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-     }
-
-    /**
      * all elements successfully put are contained
      */
     public void testPut() throws InterruptedException {
         LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            Integer I = new Integer(i);
-            q.put(I);
-            assertTrue(q.contains(I));
+            Integer x = new Integer(i);
+            q.put(x);
+            assertTrue(q.contains(x));
         }
         assertEquals(0, q.remainingCapacity());
     }
@@ -288,72 +259,95 @@ public class LinkedBlockingQueueTest ext
      */
     public void testBlockingPut() throws InterruptedException {
         final LinkedBlockingQueue q = new LinkedBlockingQueue(SIZE);
-        Thread t = new Thread(new CheckedRunnable() {
+        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());
+
+                Thread.currentThread().interrupt();
+                try {
+                    q.put(99);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+
+                pleaseInterrupt.countDown();
                 try {
                     q.put(99);
                     shouldThrow();
                 } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
             }});
 
-        t.start();
-        Thread.sleep(SHORT_DELAY_MS);
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
         t.interrupt();
-        t.join();
+        awaitTermination(t);
         assertEquals(SIZE, q.size());
         assertEquals(0, q.remainingCapacity());
     }
 
     /**
-     * put blocks waiting for take when full
+     * put blocks interruptibly waiting for take when full
      */
     public void testPutWithTake() throws InterruptedException {
         final int capacity = 2;
         final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new CheckedRunnable() {
+        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 + 1; i++)
+                for (int i = 0; i < capacity; i++)
                     q.put(i);
+                pleaseTake.countDown();
+                q.put(86);
+
+                pleaseInterrupt.countDown();
                 try {
                     q.put(99);
                     shouldThrow();
                 } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
             }});
 
-        t.start();
-        Thread.sleep(SHORT_DELAY_MS);
-        assertEquals(q.remainingCapacity(), 0);
+        await(pleaseTake);
+        assertEquals(0, q.remainingCapacity());
         assertEquals(0, q.take());
-        Thread.sleep(SHORT_DELAY_MS);
+
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
         t.interrupt();
-        t.join();
-        assertEquals(q.remainingCapacity(), 0);
+        awaitTermination(t);
+        assertEquals(0, q.remainingCapacity());
     }
 
     /**
      * timed offer times out if full and elements not taken
      */
-    public void testTimedOffer() throws InterruptedException {
+    public void testTimedOffer() {
         final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new CheckedRunnable() {
+        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
                 q.put(new Object());
                 q.put(new Object());
-                assertFalse(q.offer(new Object(), SHORT_DELAY_MS, MILLISECONDS));
+                long startTime = System.nanoTime();
+                assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS));
+                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
+                pleaseInterrupt.countDown();
                 try {
-                    q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
+                    q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
                     shouldThrow();
                 } catch (InterruptedException success) {}
             }});
 
-        t.start();
-        Thread.sleep(SMALL_DELAY_MS);
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
         t.interrupt();
-        t.join();
+        awaitTermination(t);
     }
 
     /**
@@ -367,41 +361,36 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * take blocks interruptibly when empty
-     */
-    public void testTakeFromEmpty() throws InterruptedException {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new ThreadShouldThrow(InterruptedException.class) {
-            public void realRun() throws InterruptedException {
-                q.take();
-            }};
-
-        t.start();
-        Thread.sleep(SHORT_DELAY_MS);
-        t.interrupt();
-        t.join();
-    }
-
-    /**
      * Take removes existing elements until empty, then blocks interruptibly
      */
     public void testBlockingTake() throws InterruptedException {
-        final LinkedBlockingQueue q = populatedQueue(SIZE);
-        Thread t = new Thread(new CheckedRunnable() {
+        final BlockingQueue 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());
                 }
+
+                Thread.currentThread().interrupt();
                 try {
                     q.take();
                     shouldThrow();
                 } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+
+                pleaseInterrupt.countDown();
+                try {
+                    q.take();
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
             }});
 
-        t.start();
-        Thread.sleep(SHORT_DELAY_MS);
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
         t.interrupt();
-        t.join();
+        awaitTermination(t);
     }
 
     /**
@@ -416,7 +405,7 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * timed pool with zero timeout succeeds when non-empty, else times out
+     * timed poll with zero timeout succeeds when non-empty, else times out
      */
     public void testTimedPoll0() throws InterruptedException {
         LinkedBlockingQueue q = populatedQueue(SIZE);
@@ -427,14 +416,19 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * timed pool with nonzero timeout succeeds when non-empty, else times out
+     * timed poll with nonzero timeout succeeds when non-empty, else times out
      */
     public void testTimedPoll() throws InterruptedException {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Integer> q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(i, q.poll(SHORT_DELAY_MS, MILLISECONDS));
-        }
-        assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
+            long startTime = System.nanoTime();
+            assertEquals(i, (int) q.poll(LONG_DELAY_MS, MILLISECONDS));
+            assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
+        }
+        long startTime = System.nanoTime();
+        assertNull(q.poll(timeoutMillis(), MILLISECONDS));
+        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
+        checkEmpty(q);
     }
 
     /**
@@ -442,45 +436,30 @@ public class LinkedBlockingQueueTest ext
      * returning timeout status
      */
     public void testInterruptedTimedPoll() throws InterruptedException {
-        Thread t = new Thread(new CheckedRunnable() {
+        final BlockingQueue<Integer> q = populatedQueue(SIZE);
+        final CountDownLatch aboutToWait = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                LinkedBlockingQueue q = populatedQueue(SIZE);
                 for (int i = 0; i < SIZE; ++i) {
-                    assertEquals(i, q.poll(SHORT_DELAY_MS, MILLISECONDS));
+                    long t0 = System.nanoTime();
+                    assertEquals(i, (int) q.poll(LONG_DELAY_MS, MILLISECONDS));
+                    assertTrue(millisElapsedSince(t0) < SMALL_DELAY_MS);
                 }
+                long t0 = System.nanoTime();
+                aboutToWait.countDown();
                 try {
-                    q.poll(SMALL_DELAY_MS, MILLISECONDS);
-                    shouldThrow();
-                } catch (InterruptedException success) {}
-            }});
-
-        t.start();
-        Thread.sleep(SHORT_DELAY_MS);
-        t.interrupt();
-        t.join();
-    }
-
-    /**
-     *  timed poll before a delayed offer fails; after offer succeeds;
-     *  on interruption throws
-     */
-    public void testTimedPollWithOffer() throws InterruptedException {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new CheckedRunnable() {
-            public void realRun() throws InterruptedException {
-                assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
-                assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
-                try {
-                    q.poll(LONG_DELAY_MS, MILLISECONDS);
+                    q.poll(MEDIUM_DELAY_MS, MILLISECONDS);
                     shouldThrow();
-                } catch (InterruptedException success) {}
+                } catch (InterruptedException success) {
+                    assertTrue(millisElapsedSince(t0) < MEDIUM_DELAY_MS);
+                }
             }});
 
-        t.start();
-        Thread.sleep(SMALL_DELAY_MS);
-        assertTrue(q.offer(zero, SHORT_DELAY_MS, MILLISECONDS));
+        aboutToWait.await();
+        waitForThreadToEnterWaitState(t, SMALL_DELAY_MS);
         t.interrupt();
-        t.join();
+        awaitTermination(t, MEDIUM_DELAY_MS);
+        checkEmpty(q);
     }
 
     /**
@@ -527,21 +506,6 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * remove(x) removes x and returns true if present
-     */
-    public void testRemoveElement() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        for (int i = 1; i < SIZE; i+=2) {
-            assertTrue(q.remove(new Integer(i)));
-        }
-        for (int i = 0; i < SIZE; i+=2) {
-            assertTrue(q.remove(new Integer(i)));
-            assertFalse(q.remove(new Integer(i+1)));
-        }
-        assertTrue(q.isEmpty());
-    }
-
-    /**
      * An add following remove(x) succeeds
      */
     public void testRemoveElementAndAdd() throws InterruptedException {
@@ -551,7 +515,7 @@ public class LinkedBlockingQueueTest ext
         assertTrue(q.remove(new Integer(1)));
         assertTrue(q.remove(new Integer(2)));
         assertTrue(q.add(new Integer(3)));
-        assertTrue(q.take() != null);
+        assertNotNull(q.take());
     }
 
     /**
@@ -625,65 +589,69 @@ public class LinkedBlockingQueueTest ext
             assertTrue(q.removeAll(p));
             assertEquals(SIZE-i, q.size());
             for (int j = 0; j < i; ++j) {
-                Integer I = (Integer)(p.remove());
-                assertFalse(q.contains(I));
+                Integer x = (Integer)(p.remove());
+                assertFalse(q.contains(x));
             }
         }
     }
 
     /**
-     * toArray contains all elements
+     * toArray contains all elements in FIFO order
      */
-    public void testToArray() throws InterruptedException {
+    public void testToArray() {
         LinkedBlockingQueue q = populatedQueue(SIZE);
         Object[] o = q.toArray();
         for (int i = 0; i < o.length; i++)
-            assertEquals(o[i], q.take());
+            assertSame(o[i], q.poll());
     }
 
     /**
-     * toArray(a) contains all elements
+     * toArray(a) contains all elements in FIFO order
      */
     public void testToArray2() throws InterruptedException {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue<Integer> q = populatedQueue(SIZE);
         Integer[] ints = new Integer[SIZE];
-        ints = (Integer[])q.toArray(ints);
+        Integer[] array = q.toArray(ints);
+        assertSame(ints, array);
         for (int i = 0; i < ints.length; i++)
-            assertEquals(ints[i], q.take());
+            assertSame(ints[i], q.poll());
     }
 
     /**
-     * toArray(null) throws NPE
-     */
-    public void testToArray_BadArg() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        try {
-            Object o[] = q.toArray(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
-     * toArray with incompatible array type throws CCE
+     * toArray(incompatible array type) throws ArrayStoreException
      */
     public void testToArray1_BadArg() {
         LinkedBlockingQueue q = populatedQueue(SIZE);
         try {
-            Object o[] = q.toArray(new String[10]);
+            q.toArray(new String[10]);
             shouldThrow();
         } catch (ArrayStoreException success) {}
     }
 
-
     /**
      * iterator iterates through all elements
      */
     public void testIterator() throws InterruptedException {
         LinkedBlockingQueue q = populatedQueue(SIZE);
         Iterator it = q.iterator();
-        while (it.hasNext()) {
+        int i;
+        for (i = 0; it.hasNext(); i++)
+            assertTrue(q.contains(it.next()));
+        assertEquals(i, SIZE);
+        assertIteratorExhausted(it);
+
+        it = q.iterator();
+        for (i = 0; it.hasNext(); i++)
             assertEquals(it.next(), q.take());
-        }
+        assertEquals(i, SIZE);
+        assertIteratorExhausted(it);
+    }
+
+    /**
+     * iterator of empty collection has no elements
+     */
+    public void testEmptyIterator() {
+        assertIteratorExhausted(new LinkedBlockingQueue().iterator());
     }
 
     /**
@@ -705,7 +673,6 @@ public class LinkedBlockingQueueTest ext
         assertFalse(it.hasNext());
     }
 
-
     /**
      * iterator ordering is FIFO
      */
@@ -737,7 +704,6 @@ public class LinkedBlockingQueueTest ext
         assertEquals(0, q.size());
     }
 
-
     /**
      * toString contains toStrings of elements
      */
@@ -745,11 +711,10 @@ public class LinkedBlockingQueueTest ext
         LinkedBlockingQueue q = populatedQueue(SIZE);
         String s = q.toString();
         for (int i = 0; i < SIZE; ++i) {
-            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
+            assertTrue(s.contains(String.valueOf(i)));
         }
     }
 
-
     /**
      * offer transfers elements across Executor tasks
      */
@@ -758,16 +723,18 @@ public class LinkedBlockingQueueTest ext
         q.add(one);
         q.add(two);
         ExecutorService executor = Executors.newFixedThreadPool(2);
+        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
         executor.execute(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
                 assertFalse(q.offer(three));
-                assertTrue(q.offer(three, MEDIUM_DELAY_MS, MILLISECONDS));
+                threadsStarted.await();
+                assertTrue(q.offer(three, LONG_DELAY_MS, MILLISECONDS));
                 assertEquals(0, q.remainingCapacity());
             }});
 
         executor.execute(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                Thread.sleep(SMALL_DELAY_MS);
+                threadsStarted.await();
                 assertSame(one, q.take());
             }});
 
@@ -775,21 +742,23 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * poll retrieves elements across Executor threads
+     * timed poll retrieves elements across Executor threads
      */
     public void testPollInExecutor() {
         final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
+        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
         ExecutorService executor = Executors.newFixedThreadPool(2);
         executor.execute(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
                 assertNull(q.poll());
-                assertSame(one, q.poll(MEDIUM_DELAY_MS, MILLISECONDS));
-                assertTrue(q.isEmpty());
+                threadsStarted.await();
+                assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
+                checkEmpty(q);
             }});
 
         executor.execute(new CheckedRunnable() {
             public void realRun() throws InterruptedException {
-                Thread.sleep(SMALL_DELAY_MS);
+                threadsStarted.await();
                 q.put(one);
             }});
 
@@ -800,41 +769,18 @@ public class LinkedBlockingQueueTest ext
      * A deserialized serialized queue has same elements in same order
      */
     public void testSerialization() throws Exception {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-
-        ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
-        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
-        out.writeObject(q);
-        out.close();
-
-        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
-        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
-        LinkedBlockingQueue r = (LinkedBlockingQueue)in.readObject();
-        assertEquals(q.size(), r.size());
-        while (!q.isEmpty())
-            assertEquals(q.remove(), r.remove());
-    }
-
-    /**
-     * drainTo(null) throws NPE
-     */
-    public void testDrainToNull() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        try {
-            q.drainTo(null);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
+        Queue x = populatedQueue(SIZE);
+        Queue y = serialClone(x);
 
-    /**
-     * drainTo(this) throws IAE
-     */
-    public void testDrainToSelf() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        try {
-            q.drainTo(q);
-            shouldThrow();
-        } catch (IllegalArgumentException success) {}
+        assertNotSame(x, y);
+        assertEquals(x.size(), y.size());
+        assertEquals(x.toString(), y.toString());
+        assertTrue(Arrays.equals(x.toArray(), y.toArray()));
+        while (!x.isEmpty()) {
+            assertFalse(y.isEmpty());
+            assertEquals(x.remove(), y.remove());
+        }
+        assertTrue(y.isEmpty());
     }
 
     /**
@@ -844,8 +790,8 @@ public class LinkedBlockingQueueTest ext
         LinkedBlockingQueue q = populatedQueue(SIZE);
         ArrayList l = new ArrayList();
         q.drainTo(l);
-        assertEquals(q.size(), 0);
-        assertEquals(l.size(), SIZE);
+        assertEquals(0, q.size());
+        assertEquals(SIZE, l.size());
         for (int i = 0; i < SIZE; ++i)
             assertEquals(l.get(i), new Integer(i));
         q.add(zero);
@@ -855,8 +801,8 @@ public class LinkedBlockingQueueTest ext
         assertTrue(q.contains(one));
         l.clear();
         q.drainTo(l);
-        assertEquals(q.size(), 0);
-        assertEquals(l.size(), 2);
+        assertEquals(0, q.size());
+        assertEquals(2, l.size());
         for (int i = 0; i < 2; ++i)
             assertEquals(l.get(i), new Integer(i));
     }
@@ -882,29 +828,7 @@ public class LinkedBlockingQueueTest ext
     }
 
     /**
-     * drainTo(null, n) throws NPE
-     */
-    public void testDrainToNullN() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        try {
-            q.drainTo(null, 0);
-            shouldThrow();
-        } catch (NullPointerException success) {}
-    }
-
-    /**
-     * drainTo(this, n) throws IAE
-     */
-    public void testDrainToSelfN() {
-        LinkedBlockingQueue q = populatedQueue(SIZE);
-        try {
-            q.drainTo(q, 0);
-            shouldThrow();
-        } catch (IllegalArgumentException success) {}
-    }
-
-    /**
-     * drainTo(c, n) empties first max {n, size} elements of queue into c
+     * drainTo(c, n) empties first min(n, size) elements of queue into c
      */
     public void testDrainToN() {
         LinkedBlockingQueue q = new LinkedBlockingQueue();
@@ -913,12 +837,27 @@ public class LinkedBlockingQueueTest ext
                 assertTrue(q.offer(new Integer(j)));
             ArrayList l = new ArrayList();
             q.drainTo(l, i);
-            int k = (i < SIZE)? i : SIZE;
-            assertEquals(l.size(), k);
-            assertEquals(q.size(), SIZE-k);
+            int k = (i < SIZE) ? i : SIZE;
+            assertEquals(k, l.size());
+            assertEquals(SIZE-k, q.size());
             for (int j = 0; j < k; ++j)
                 assertEquals(l.get(j), new Integer(j));
-            while (q.poll() != null) ;
+            do {} while (q.poll() != null);
+        }
+    }
+
+    /**
+     * remove(null), contains(null) always return false
+     */
+    public void testNeverContainsNull() {
+        Collection<?>[] qs = {
+            new LinkedBlockingQueue<Object>(),
+            populatedQueue(2),
+        };
+
+        for (Collection<?> q : qs) {
+            assertFalse(q.contains(null));
+            assertFalse(q.remove(null));
         }
     }