--- jsr166/src/test/tck/LinkedBlockingQueueTest.java	2003/09/07 20:39:11	1.2
+++ jsr166/src/test/tck/LinkedBlockingQueueTest.java	2012/02/21 02:04:17	1.51
@@ -1,522 +1,556 @@
 /*
- * Written by members of JCP JSR-166 Expert Group and released to the
- * public domain. Use, modify, and redistribute this code in any way
- * without acknowledgement. Other contributors include Andrew Wright,
- * Jeffrey Hayes, Pat Fischer, Mike Judd.
+ * 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/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 java.io.*;
-
-public class LinkedBlockingQueueTest extends TestCase {
-
-    private static int N = 10;
-    private static long SHORT_DELAY_MS = 100; 
-    private static long MEDIUM_DELAY_MS = 1000;
-    private static long LONG_DELAY_MS = 10000; 
+import java.util.Arrays;
+import java.util.ArrayList;
+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.LinkedBlockingQueue;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+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());	
+        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 fullQueue(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)));
+        for (int i = 0; i < n; i++)
+            assertTrue(q.offer(new Integer(i)));
         assertFalse(q.isEmpty());
         assertEquals(0, q.remainingCapacity());
-	assertEquals(n, q.size());
+        assertEquals(n, q.size());
         return q;
     }
- 
-    public void testConstructor1(){
-        assertEquals(N, new LinkedBlockingQueue(N).remainingCapacity());
+
+    /**
+     * A new queue has the indicated capacity, or Integer.MAX_VALUE if
+     * none given
+     */
+    public void testConstructor1() {
+        assertEquals(SIZE, new LinkedBlockingQueue(SIZE).remainingCapacity());
+        assertEquals(Integer.MAX_VALUE, new LinkedBlockingQueue().remainingCapacity());
     }
 
-    public void testConstructor2(){
+    /**
+     * Constructor throws IllegalArgumentException if capacity argument nonpositive
+     */
+    public void testConstructor2() {
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(0);
-            fail("Cannot make zero-sized");
-        }
-        catch (IllegalArgumentException success) {}
+            new LinkedBlockingQueue(0);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
     }
 
-    public void testConstructor3(){
-
+    /**
+     * Initializing from null Collection throws NullPointerException
+     */
+    public void testConstructor3() {
         try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(null);
-            fail("Cannot make from null collection");
-        }
-        catch (NullPointerException success) {}
+            new LinkedBlockingQueue(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
-    public void testConstructor4(){
+    /**
+     * Initializing from Collection of null elements throws NullPointerException
+     */
+    public void testConstructor4() {
+        Collection<Integer> elements = Arrays.asList(new Integer[SIZE]);
         try {
-            Integer[] ints = new Integer[N];
-            LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
-            fail("Cannot make with null elements");
-        }
-        catch (NullPointerException success) {}
+            new LinkedBlockingQueue(elements);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
-    public void testConstructor5(){
-        try {
-            Integer[] ints = new Integer[N];
-            for (int i = 0; i < N-1; ++i)
-                ints[i] = new Integer(i);
-            LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
-            fail("Cannot make with null elements");
-        }
-        catch (NullPointerException success) {}
+    /**
+     * 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 {
+            new LinkedBlockingQueue(elements);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
-    public void testConstructor6(){
-        try {
-            Integer[] ints = new Integer[N];
-            for (int i = 0; i < N; ++i)
-                ints[i] = new Integer(i);
-            LinkedBlockingQueue q = new LinkedBlockingQueue(Arrays.asList(ints));
-            for (int i = 0; i < N; ++i)
-                assertEquals(ints[i], q.poll());
-        }
-        finally {}
+    /**
+     * 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));
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(ints[i], q.poll());
     }
 
+    /**
+     * Queue transitions from empty to full when elements added
+     */
     public void testEmptyFull() {
         LinkedBlockingQueue q = new LinkedBlockingQueue(2);
         assertTrue(q.isEmpty());
         assertEquals("should have room for 2", 2, q.remainingCapacity());
-        q.add(new Integer(1));
+        q.add(one);
         assertFalse(q.isEmpty());
-        q.add(new Integer(2));
+        q.add(two);
         assertFalse(q.isEmpty());
-        assertEquals("queue should be full", 0, q.remainingCapacity());
-        assertFalse("offer should be rejected", q.offer(new Integer(3)));
+        assertEquals(0, q.remainingCapacity());
+        assertFalse(q.offer(three));
     }
 
-    public void testRemainingCapacity(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
+    /**
+     * remainingCapacity decreases on add, increases on remove
+     */
+    public void testRemainingCapacity() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             assertEquals(i, q.remainingCapacity());
-            assertEquals(N-i, q.size());
+            assertEquals(SIZE-i, q.size());
             q.remove();
         }
-        for (int i = 0; i < N; ++i) {
-            assertEquals(N-i, q.remainingCapacity());
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(SIZE-i, q.remainingCapacity());
             assertEquals(i, q.size());
             q.add(new Integer(i));
         }
     }
 
-    public void testOfferNull(){
-	try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            q.offer(null);
-            fail("should throw NPE");
-        } catch (NullPointerException success) { }   
+    /**
+     * Offer succeeds if not full; fails if full
+     */
+    public void testOffer() {
+        LinkedBlockingQueue q = new LinkedBlockingQueue(1);
+        assertTrue(q.offer(zero));
+        assertFalse(q.offer(one));
     }
 
-    public void testOffer(){
-        LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-        assertTrue(q.offer(new Integer(0)));
-        assertFalse(q.offer(new Integer(1)));
+    /**
+     * 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 {
+            q.add(new Integer(SIZE));
+            shouldThrow();
+        } catch (IllegalStateException success) {}
     }
 
-    public void testAdd(){
-	try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-            for (int i = 0; i < N; ++i) {
-                assertTrue(q.add(new Integer(i)));
-            }
-            assertEquals(0, q.remainingCapacity());
-            q.add(new Integer(N));
-        } catch (IllegalStateException success){
-	}   
-    }
-
-    public void testAddAll1(){
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            q.addAll(null);
-            fail("Cannot add null collection");
-        }
-        catch (NullPointerException success) {}
-    }
-    public void testAddAll2(){
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-            Integer[] ints = new Integer[N];
-            q.addAll(Arrays.asList(ints));
-            fail("Cannot add null elements");
-        }
-        catch (NullPointerException success) {}
-    }
-    public void testAddAll3(){
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-            Integer[] ints = new Integer[N];
-            for (int i = 0; i < N-1; ++i)
-                ints[i] = new Integer(i);
-            q.addAll(Arrays.asList(ints));
-            fail("Cannot add null elements");
-        }
-        catch (NullPointerException success) {}
-    }
-    public void testAddAll4(){
-        try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(1);
-            Integer[] ints = new Integer[N];
-            for (int i = 0; i < N; ++i)
-                ints[i] = new Integer(i);
-            q.addAll(Arrays.asList(ints));
-            fail("Cannot add with insufficient capacity");
-        }
-        catch (IllegalStateException success) {}
-    }
-    public void testAddAll5(){
-        try {
-            Integer[] empty = new Integer[0];
-            Integer[] ints = new Integer[N];
-            for (int i = 0; i < N; ++i)
-                ints[i] = new Integer(i);
-            LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-            assertFalse(q.addAll(Arrays.asList(empty)));
-            assertTrue(q.addAll(Arrays.asList(ints)));
-            for (int i = 0; i < N; ++i)
-                assertEquals(ints[i], q.poll());
-        }
-        finally {}
-    }
-
-     public void testPutNull() {
-	try {
-            LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-            q.put(null);
-            fail("put should throw NPE");
-        } 
-        catch (NullPointerException success){
-	}   
-        catch (InterruptedException ie) {
-	    fail("Unexpected exception");
-        }
-     }
-
-     public void testPut() {
-         try {
-             LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-             for (int i = 0; i < N; ++i) {
-                 Integer I = new Integer(i);
-                 q.put(I);
-                 assertTrue(q.contains(I));
-             }
-             assertEquals(0, q.remainingCapacity());
-         }
-        catch (InterruptedException ie) {
-	    fail("Unexpected exception");
-        }
-    }
-
-    public void testBlockingPut(){
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    int added = 0;
-                    try {
-                        LinkedBlockingQueue q = new LinkedBlockingQueue(N);
-                        for (int i = 0; i < N; ++i) {
-                            q.put(new Integer(i));
-                            ++added;
-                        }
-                        q.put(new Integer(N));
-                        fail("put should block");
-                    } catch (InterruptedException ie){
-                        assertEquals(added, N);
-                    }   
-                }});
-        t.start();
-        try { 
-           Thread.sleep(SHORT_DELAY_MS); 
-           t.interrupt();
-           t.join();
-        }
-        catch (InterruptedException ie) {
-	    fail("Unexpected exception");
+    /**
+     * addAll(this) throws IllegalArgumentException
+     */
+    public void testAddAllSelf() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        try {
+            q.addAll(q);
+            shouldThrow();
+        } catch (IllegalArgumentException 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 {
+            q.addAll(elements);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * 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 {
+            q.addAll(elements);
+            shouldThrow();
+        } catch (IllegalStateException success) {}
+    }
+
+    /**
+     * 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);
+        assertFalse(q.addAll(Arrays.asList(empty)));
+        assertTrue(q.addAll(Arrays.asList(ints)));
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(ints[i], q.poll());
+    }
+
+    /**
+     * 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));
         }
+        assertEquals(0, q.remainingCapacity());
     }
 
-    public void testPutWithTake() {
+    /**
+     * put blocks interruptibly if full
+     */
+    public void testBlockingPut() throws InterruptedException {
+        final LinkedBlockingQueue 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());
+
+                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());
+            }});
+
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
+        t.interrupt();
+        awaitTermination(t);
+        assertEquals(SIZE, q.size());
+        assertEquals(0, q.remainingCapacity());
+    }
+
+    /**
+     * 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 Runnable() {
-                public void run(){
-                    int added = 0;
-                    try {
-                        q.put(new Object());
-                        ++added;
-                        q.put(new Object());
-                        ++added;
-                        q.put(new Object());
-                        ++added;
-                        q.put(new Object());
-                        ++added;
-			fail("Should block");
-                    } catch (InterruptedException e){
-                        assertTrue(added >= 2);
-                    }
-                }
-            });
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            q.take();
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            fail("Unexpected exception");
-        }
+        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);
+                pleaseTake.countDown();
+                q.put(86);
+
+                pleaseInterrupt.countDown();
+                try {
+                    q.put(99);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+            }});
+
+        await(pleaseTake);
+        assertEquals(0, q.remainingCapacity());
+        assertEquals(0, q.take());
+
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
+        t.interrupt();
+        awaitTermination(t);
+        assertEquals(0, q.remainingCapacity());
     }
 
+    /**
+     * timed offer times out if full and elements not taken
+     */
     public void testTimedOffer() {
         final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new Runnable() {
-                public void run(){
-                    try {
-                        q.put(new Object());
-                        q.put(new Object());
-                        assertFalse(q.offer(new Object(), SHORT_DELAY_MS/2, TimeUnit.MILLISECONDS));
-                        q.offer(new Object(), LONG_DELAY_MS, TimeUnit.MILLISECONDS);
-			fail("Should block");
-                    } catch (InterruptedException success){}
-                }
-            });
-        
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            fail("Unexpected exception");
-        }
+        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                q.put(new Object());
+                q.put(new Object());
+                long startTime = System.nanoTime();
+                assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS));
+                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
+                pleaseInterrupt.countDown();
+                try {
+                    q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+            }});
+
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
+        t.interrupt();
+        awaitTermination(t);
     }
 
-    public void testTake(){
-	try {
-            LinkedBlockingQueue q = fullQueue(N);
-            for (int i = 0; i < N; ++i) {
-                assertEquals(i, ((Integer)q.take()).intValue());
-            }
-        } catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}   
+    /**
+     * take retrieves elements in FIFO order
+     */
+    public void testTake() throws InterruptedException {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.take());
+        }
     }
 
-    public void testTakeFromEmpty() {
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new Runnable() {
-                public void run(){
-                    try {
-                        q.take();
-			fail("Should block");
-                    } catch (InterruptedException success){ }                
+    /**
+     * Take removes existing elements until empty, then blocks interruptibly
+     */
+    public void testBlockingTake() throws InterruptedException {
+        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());
                 }
-            });
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            fail("Unexpected exception");
-        }
+
+                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());
+            }});
+
+        await(pleaseInterrupt);
+        assertThreadStaysAlive(t);
+        t.interrupt();
+        awaitTermination(t);
     }
 
-    public void testBlockingTake(){
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        LinkedBlockingQueue q = fullQueue(N);
-                        for (int i = 0; i < N; ++i) {
-                            assertEquals(i, ((Integer)q.take()).intValue());
-                        }
-                        q.take();
-                        fail("take should block");
-                    } catch (InterruptedException success){
-                    }   
-                }});
-        t.start();
-        try { 
-           Thread.sleep(SHORT_DELAY_MS); 
-           t.interrupt();
-           t.join();
-        }
-        catch (InterruptedException ie) {
-	    fail("Unexpected exception");
+    /**
+     * poll succeeds unless empty
+     */
+    public void testPoll() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.poll());
         }
+        assertNull(q.poll());
     }
 
-
-    public void testPoll(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
-            assertEquals(i, ((Integer)q.poll()).intValue());
+    /**
+     * timed poll with zero timeout succeeds when non-empty, else times out
+     */
+    public void testTimedPoll0() throws InterruptedException {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.poll(0, MILLISECONDS));
         }
-	assertNull(q.poll());
+        assertNull(q.poll(0, MILLISECONDS));
     }
 
-    public void testTimedPoll0() {
-        try {
-            LinkedBlockingQueue q = fullQueue(N);
-            for (int i = 0; i < N; ++i) {
-                assertEquals(i, ((Integer)q.poll(0, TimeUnit.MILLISECONDS)).intValue());
-            }
-            assertNull(q.poll(0, TimeUnit.MILLISECONDS));
-        } catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}   
+    /**
+     * timed poll with nonzero timeout succeeds when non-empty, else times out
+     */
+    public void testTimedPoll() throws InterruptedException {
+        LinkedBlockingQueue<Integer> q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            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);
     }
 
-    public void testTimedPoll() {
-        try {
-            LinkedBlockingQueue q = fullQueue(N);
-            for (int i = 0; i < N; ++i) {
-                assertEquals(i, ((Integer)q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)).intValue());
-            }
-            assertNull(q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-        } catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}   
-    }
-
-    public void testInterruptedTimedPoll(){
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        LinkedBlockingQueue q = fullQueue(N);
-                        for (int i = 0; i < N; ++i) {
-                            assertEquals(i, ((Integer)q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)).intValue());
-                        }
-                        assertNull(q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-                    } catch (InterruptedException success){
-                    }   
-                }});
-        t.start();
-        try { 
-           Thread.sleep(SHORT_DELAY_MS); 
-           t.interrupt();
-           t.join();
-        }
-        catch (InterruptedException ie) {
-	    fail("Unexpected exception");
-        }
+    /**
+     * Interrupted timed poll throws InterruptedException instead of
+     * returning timeout status
+     */
+    public void testInterruptedTimedPoll() throws InterruptedException {
+        final BlockingQueue<Integer> q = populatedQueue(SIZE);
+        final CountDownLatch aboutToWait = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                for (int i = 0; i < SIZE; ++i) {
+                    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(MEDIUM_DELAY_MS, MILLISECONDS);
+                    shouldThrow();
+                } catch (InterruptedException success) {
+                    assertTrue(millisElapsedSince(t0) < MEDIUM_DELAY_MS);
+                }
+            }});
+
+        aboutToWait.await();
+        waitForThreadToEnterWaitState(t, SMALL_DELAY_MS);
+        t.interrupt();
+        awaitTermination(t, MEDIUM_DELAY_MS);
+        checkEmpty(q);
     }
 
-    public void testTimedPollWithOffer(){
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-        Thread t = new Thread(new Runnable() {
-                public void run(){
-                    try {
-                        assertNull(q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-                        q.poll(LONG_DELAY_MS, TimeUnit.MILLISECONDS);
-                        q.poll(LONG_DELAY_MS, TimeUnit.MILLISECONDS);
-			fail("Should block");
-                    } catch (InterruptedException success) { }                
-                }
-            });
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS * 2);
-            assertTrue(q.offer(new Integer(0), SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            fail("Unexpected exception");
-        }
-    }  
-
-
-    public void testPeek(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
-            assertEquals(i, ((Integer)q.peek()).intValue());
-            q.poll();
+    /**
+     * peek returns next element, or null if empty
+     */
+    public void testPeek() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.peek());
+            assertEquals(i, q.poll());
             assertTrue(q.peek() == null ||
-                       i != ((Integer)q.peek()).intValue());
+                       !q.peek().equals(i));
         }
-	assertNull(q.peek());
+        assertNull(q.peek());
     }
 
-    public void testElement(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
-            assertEquals(i, ((Integer)q.element()).intValue());
-            q.poll();
+    /**
+     * element returns next element, or throws NSEE if empty
+     */
+    public void testElement() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.element());
+            assertEquals(i, q.poll());
         }
         try {
             q.element();
-            fail("no such element");
-        }
-        catch (NoSuchElementException success) {}
+            shouldThrow();
+        } catch (NoSuchElementException success) {}
     }
 
-    public void testRemove(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
-            assertEquals(i, ((Integer)q.remove()).intValue());
+    /**
+     * remove removes next element, or throws NSEE if empty
+     */
+    public void testRemove() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(i, q.remove());
         }
         try {
             q.remove();
-            fail("remove should throw");
-        } catch (NoSuchElementException success){
-	}   
+            shouldThrow();
+        } catch (NoSuchElementException success) {}
     }
 
-    public void testRemoveElement(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 1; i < N; i+=2) {
-            assertTrue(q.remove(new Integer(i)));
-        }
-        for (int i = 0; i < N; 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 {
+        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)));
+        assertTrue(q.take() != null);
     }
-	
-    public void testContains(){
-        LinkedBlockingQueue q = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
+
+    /**
+     * contains(x) reports true when elements added but not yet removed
+     */
+    public void testContains() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             assertTrue(q.contains(new Integer(i)));
             q.poll();
             assertFalse(q.contains(new Integer(i)));
         }
     }
 
-    public void testClear(){
-        LinkedBlockingQueue q = fullQueue(N);
+    /**
+     * clear removes all elements
+     */
+    public void testClear() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
         q.clear();
         assertTrue(q.isEmpty());
         assertEquals(0, q.size());
-        assertEquals(N, q.remainingCapacity());
-        q.add(new Integer(1));
+        assertEquals(SIZE, q.remainingCapacity());
+        q.add(one);
         assertFalse(q.isEmpty());
+        assertTrue(q.contains(one));
         q.clear();
         assertTrue(q.isEmpty());
     }
 
-    public void testContainsAll(){
-        LinkedBlockingQueue q = fullQueue(N);
-        LinkedBlockingQueue p = new LinkedBlockingQueue(N);
-        for (int i = 0; i < N; ++i) {
+    /**
+     * containsAll(c) is true when c contains a subset of elements
+     */
+    public void testContainsAll() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue p = new LinkedBlockingQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             assertTrue(q.containsAll(p));
             assertFalse(p.containsAll(q));
             p.add(new Integer(i));
@@ -524,10 +558,13 @@ public class LinkedBlockingQueueTest ext
         assertTrue(p.containsAll(q));
     }
 
-    public void testRetainAll(){
-        LinkedBlockingQueue q = fullQueue(N);
-        LinkedBlockingQueue p = fullQueue(N);
-        for (int i = 0; i < N; ++i) {
+    /**
+     * retainAll(c) retains only those elements of c and reports true if changed
+     */
+    public void testRetainAll() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        LinkedBlockingQueue p = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             boolean changed = q.retainAll(p);
             if (i == 0)
                 assertFalse(changed);
@@ -535,17 +572,20 @@ public class LinkedBlockingQueueTest ext
                 assertTrue(changed);
 
             assertTrue(q.containsAll(p));
-            assertEquals(N-i, q.size());
+            assertEquals(SIZE-i, q.size());
             p.remove();
         }
     }
 
-    public void testRemoveAll(){
-        for (int i = 1; i < N; ++i) {
-            LinkedBlockingQueue q = fullQueue(N);
-            LinkedBlockingQueue p = fullQueue(i);
+    /**
+     * removeAll(c) removes only those elements of c and reports true if changed
+     */
+    public void testRemoveAll() {
+        for (int i = 1; i < SIZE; ++i) {
+            LinkedBlockingQueue q = populatedQueue(SIZE);
+            LinkedBlockingQueue p = populatedQueue(i);
             assertTrue(q.removeAll(p));
-            assertEquals(N-i, q.size());
+            assertEquals(SIZE-i, q.size());
             for (int j = 0; j < i; ++j) {
                 Integer I = (Integer)(p.remove());
                 assertFalse(q.contains(I));
@@ -553,183 +593,239 @@ public class LinkedBlockingQueueTest ext
         }
     }
 
-
-    public void testToArray(){
-        LinkedBlockingQueue q = fullQueue(N);
-	Object[] o = q.toArray();
-	try {
-	for(int i = 0; i < o.length; i++)
-	    assertEquals(o[i], q.take());
-	} catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}    
-    }
-
-    public void testToArray2(){
-        LinkedBlockingQueue q = fullQueue(N);
-	Integer[] ints = new Integer[N];
-	ints = (Integer[])q.toArray(ints);
-	try {
-	    for(int i = 0; i < ints.length; i++)
-		assertEquals(ints[i], q.take());
-	} catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}    
-    }
-    
-    public void testIterator(){
-        LinkedBlockingQueue q = fullQueue(N);
-	Iterator it = q.iterator();
-	try {
-	    while(it.hasNext()){
-		assertEquals(it.next(), q.take());
-	    }
-	} catch (InterruptedException e){
-	    fail("Unexpected exception");
-	}    
+    /**
+     * 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());
     }
 
-    public void testIteratorOrdering() {
+    /**
+     * 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());
+    }
 
-        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+    /**
+     * toArray(incompatible array type) throws ArrayStoreException
+     */
+    public void testToArray1_BadArg() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        try {
+            q.toArray(new String[10]);
+            shouldThrow();
+        } catch (ArrayStoreException success) {}
+    }
 
-        q.add(new Integer(1));
-        q.add(new Integer(2));
-        q.add(new Integer(3));
+    /**
+     * iterator iterates through all elements
+     */
+    public void testIterator() throws InterruptedException {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        Iterator it = q.iterator();
+        while (it.hasNext()) {
+            assertEquals(it.next(), q.take());
+        }
+    }
 
-        assertEquals("queue should be full", 0, q.remainingCapacity());
+    /**
+     * iterator.remove removes current element
+     */
+    public void testIteratorRemove() {
+        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+        q.add(two);
+        q.add(one);
+        q.add(three);
+
+        Iterator it = q.iterator();
+        it.next();
+        it.remove();
+
+        it = q.iterator();
+        assertSame(it.next(), one);
+        assertSame(it.next(), three);
+        assertFalse(it.hasNext());
+    }
 
+    /**
+     * iterator ordering is FIFO
+     */
+    public void testIteratorOrdering() {
+        final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
+        q.add(one);
+        q.add(two);
+        q.add(three);
+        assertEquals(0, q.remainingCapacity());
         int k = 0;
         for (Iterator it = q.iterator(); it.hasNext();) {
-            int i = ((Integer)(it.next())).intValue();
-            assertEquals("items should come out in order", ++k, i);
+            assertEquals(++k, it.next());
         }
-
-        assertEquals("should go through 3 elements", 3, k);
+        assertEquals(3, k);
     }
 
-    public void testWeaklyConsistentIteration () {
-
+    /**
+     * Modifications do not cause iterators to fail
+     */
+    public void testWeaklyConsistentIteration() {
         final LinkedBlockingQueue q = new LinkedBlockingQueue(3);
-
-        q.add(new Integer(1));
-        q.add(new Integer(2));
-        q.add(new Integer(3));
-
-        try {
-            for (Iterator it = q.iterator(); it.hasNext();) {
-                q.remove();
-                it.next();
-            }
-        }
-        catch (ConcurrentModificationException e) {
-            fail("weakly consistent iterator; should not get CME");
+        q.add(one);
+        q.add(two);
+        q.add(three);
+        for (Iterator it = q.iterator(); it.hasNext();) {
+            q.remove();
+            it.next();
         }
-
-        assertEquals("queue should be empty again", 0, q.size());
+        assertEquals(0, q.size());
     }
 
-
-    public void testToString(){
-        LinkedBlockingQueue q = fullQueue(N);
+    /**
+     * toString contains toStrings of elements
+     */
+    public void testToString() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
         String s = q.toString();
-        for (int i = 0; i < N; ++i) {
-            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
+        for (int i = 0; i < SIZE; ++i) {
+            assertTrue(s.contains(String.valueOf(i)));
         }
-    }        
-
+    }
 
+    /**
+     * offer transfers elements across Executor tasks
+     */
     public void testOfferInExecutor() {
-
         final LinkedBlockingQueue q = new LinkedBlockingQueue(2);
-
-        q.add(new Integer(1));
-        q.add(new Integer(2));
-
+        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));
+                threadsStarted.await();
+                assertTrue(q.offer(three, LONG_DELAY_MS, MILLISECONDS));
+                assertEquals(0, q.remainingCapacity());
+            }});
+
+        executor.execute(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                threadsStarted.await();
+                assertSame(one, q.take());
+            }});
 
-        executor.execute(new Runnable() {
-            public void run() {
-                assertFalse("offer should be rejected", q.offer(new Integer(3)));
-                try {
-                    assertTrue("offer should be accepted", q.offer(new Integer(3), MEDIUM_DELAY_MS * 2, TimeUnit.MILLISECONDS));
-                    assertEquals(0, q.remainingCapacity());
-                }
-                catch (InterruptedException e) {
-                    fail("should not be interrupted");
-                }
-            }
-        });
-
-        executor.execute(new Runnable() {
-            public void run() {
-                try {
-                    Thread.sleep(MEDIUM_DELAY_MS);
-                    assertEquals("first item in queue should be 1", new Integer(1), q.take());
-                }
-                catch (InterruptedException e) {
-                    fail("should not be interrupted");
-                }
-            }
-        });
-        
-        executor.shutdown();
-
+        joinPool(executor);
     }
 
+    /**
+     * 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());
+                threadsStarted.await();
+                assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
+                checkEmpty(q);
+            }});
+
+        executor.execute(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                threadsStarted.await();
+                q.put(one);
+            }});
 
-        executor.execute(new Runnable() {
-            public void run() {
-                assertNull("poll should fail", q.poll());
-                try {
-                    assertTrue(null != q.poll(MEDIUM_DELAY_MS * 2, TimeUnit.MILLISECONDS));
-                    assertTrue(q.isEmpty());
-                }
-                catch (InterruptedException e) {
-                    fail("should not be interrupted");
-                }
-            }
-        });
+        joinPool(executor);
+    }
 
-        executor.execute(new Runnable() {
-            public void run() {
-                try {
-                    Thread.sleep(MEDIUM_DELAY_MS);
-                    q.put(new Integer(1));
-                }
-                catch (InterruptedException e) {
-                    fail("should not be interrupted");
-                }
-            }
-        });
-        
-        executor.shutdown();
+    /**
+     * A deserialized serialized queue has same elements in same order
+     */
+    public void testSerialization() throws Exception {
+        Queue x = populatedQueue(SIZE);
+        Queue y = serialClone(x);
+
+        assertTrue(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());
+    }
+
+    /**
+     * drainTo(c) empties queue into another collection c
+     */
+    public void testDrainTo() {
+        LinkedBlockingQueue q = populatedQueue(SIZE);
+        ArrayList l = new ArrayList();
+        q.drainTo(l);
+        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);
+        q.add(one);
+        assertFalse(q.isEmpty());
+        assertTrue(q.contains(zero));
+        assertTrue(q.contains(one));
+        l.clear();
+        q.drainTo(l);
+        assertEquals(0, q.size());
+        assertEquals(2, l.size());
+        for (int i = 0; i < 2; ++i)
+            assertEquals(l.get(i), new Integer(i));
+    }
+
+    /**
+     * drainTo empties full queue, unblocking a waiting put.
+     */
+    public void testDrainToWithActivePut() throws InterruptedException {
+        final LinkedBlockingQueue q = populatedQueue(SIZE);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                q.put(new Integer(SIZE+1));
+            }});
 
+        t.start();
+        ArrayList l = new ArrayList();
+        q.drainTo(l);
+        assertTrue(l.size() >= SIZE);
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(l.get(i), new Integer(i));
+        t.join();
+        assertTrue(q.size() + l.size() >= SIZE);
     }
 
-    public void testSerialization() {
-        LinkedBlockingQueue q = fullQueue(N);
-
-        try {
-            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());
-        } catch(Exception e){
-            e.printStackTrace();
-            fail("unexpected exception");
+    /**
+     * drainTo(c, n) empties first min(n, size) elements of queue into c
+     */
+    public void testDrainToN() {
+        LinkedBlockingQueue 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();
+            q.drainTo(l, i);
+            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) ;
         }
     }