--- jsr166/src/test/tck/DelayQueueTest.java	2003/09/20 18:20:07	1.4
+++ jsr166/src/test/tck/DelayQueueTest.java	2017/05/14 01:30:34	1.87
@@ -1,101 +1,102 @@
 /*
- * 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 static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Delayed;
+import java.util.concurrent.DelayQueue;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import junit.framework.Test;
 
 public class DelayQueueTest extends JSR166TestCase {
+
+    public static class Generic extends BlockingQueueTest {
+        protected BlockingQueue emptyCollection() {
+            return new DelayQueue();
+        }
+        protected PDelay makeElement(int i) {
+            return new PDelay(i);
+        }
+    }
+
     public static void main(String[] args) {
-	junit.textui.TestRunner.run (suite());	
+        main(suite(), args);
     }
 
     public static Test suite() {
-	return new TestSuite(DelayQueueTest.class);
+        class Implementation implements CollectionImplementation {
+            public Class<?> klazz() { return DelayQueue.class; }
+            public Collection emptyCollection() { return new DelayQueue(); }
+            public Object makeElement(int i) { return new PDelay(i); }
+            public boolean isConcurrent() { return true; }
+            public boolean permitsNulls() { return false; }
+        }
+        return newTestSuite(DelayQueueTest.class,
+                            new Generic().testSuite(),
+                            CollectionTest.testSuite(new Implementation()));
     }
 
-    private static final int NOCAP = Integer.MAX_VALUE;
-
     /**
-     * A delayed implmentation for testing.
-     * Most Q/BQ tests use Pseudodelays, where delays are all elapsed
+     * A fake Delayed implementation for testing.
+     * Most tests use PDelays, where delays are all elapsed
      * (so, no blocking solely for delays) but are still ordered
-     */ 
-    static class PDelay implements Delayed { 
-        int pseudodelay;
-        PDelay(int i) { pseudodelay = Integer.MIN_VALUE + i; }
-        public int compareTo(Object y) {
-            int i = pseudodelay;
-            int j = ((PDelay)y).pseudodelay;
-            if (i < j) return -1;
-            if (i > j) return 1;
-            return 0;
-        }
-
-        public int compareTo(PDelay y) {
-            int i = pseudodelay;
-            int j = ((PDelay)y).pseudodelay;
-            if (i < j) return -1;
-            if (i > j) return 1;
-            return 0;
+     */
+    static class PDelay implements Delayed {
+        final int pseudodelay;
+        PDelay(int pseudodelay) { this.pseudodelay = pseudodelay; }
+        public int compareTo(Delayed y) {
+            return Integer.compare(this.pseudodelay, ((PDelay)y).pseudodelay);
         }
-
         public boolean equals(Object other) {
-            return ((PDelay)other).pseudodelay == pseudodelay;
-        }
-        public boolean equals(PDelay other) {
-            return ((PDelay)other).pseudodelay == pseudodelay;
+            return (other instanceof PDelay) &&
+                this.pseudodelay == ((PDelay)other).pseudodelay;
         }
-
-
+        // suppress [overrides] javac warning
+        public int hashCode() { return pseudodelay; }
         public long getDelay(TimeUnit ignore) {
-            return pseudodelay;
-        }
-        public int intValue() {
-            return pseudodelay;
+            return Integer.MIN_VALUE + pseudodelay;
         }
-
         public String toString() {
             return String.valueOf(pseudodelay);
         }
     }
 
-
     /**
      * Delayed implementation that actually delays
      */
-    static class NanoDelay implements Delayed { 
-        long trigger;
-        NanoDelay(long i) { 
+    static class NanoDelay implements Delayed {
+        final long trigger;
+        NanoDelay(long i) {
             trigger = System.nanoTime() + i;
         }
-        public int compareTo(Object y) {
-            long i = trigger;
-            long j = ((NanoDelay)y).trigger;
-            if (i < j) return -1;
-            if (i > j) return 1;
-            return 0;
-        }
 
-        public int compareTo(NanoDelay y) {
-            long i = trigger;
-            long j = ((NanoDelay)y).trigger;
-            if (i < j) return -1;
-            if (i > j) return 1;
-            return 0;
+        public int compareTo(Delayed y) {
+            return Long.compare(trigger, ((NanoDelay)y).trigger);
         }
 
         public boolean equals(Object other) {
-            return ((NanoDelay)other).trigger == trigger;
-        }
-        public boolean equals(NanoDelay other) {
-            return ((NanoDelay)other).trigger == trigger;
+            return (other instanceof NanoDelay) &&
+                this.trigger == ((NanoDelay)other).trigger;
         }
 
+        // suppress [overrides] javac warning
+        public int hashCode() { return (int) trigger; }
+
         public long getDelay(TimeUnit unit) {
             long n = trigger - System.nanoTime();
             return unit.convert(n, TimeUnit.NANOSECONDS);
@@ -110,90 +111,83 @@ public class DelayQueueTest extends JSR1
         }
     }
 
-
     /**
-     * Create a queue of given size containing consecutive
-     * PDelays 0 ... n.
+     * Returns a new queue of given size containing consecutive
+     * PDelays 0 ... n - 1.
      */
-    private DelayQueue populatedQueue(int n) {
-        DelayQueue q = new DelayQueue();
+    private static DelayQueue<PDelay> populatedQueue(int n) {
+        DelayQueue<PDelay> q = new DelayQueue<>();
         assertTrue(q.isEmpty());
-	for(int i = n-1; i >= 0; i-=2)
-	    assertTrue(q.offer(new PDelay(i)));
-	for(int i = (n & 1); i < n; i+=2)
-	    assertTrue(q.offer(new PDelay(i)));
+        for (int i = n - 1; i >= 0; i -= 2)
+            assertTrue(q.offer(new PDelay(i)));
+        for (int i = (n & 1); i < n; i += 2)
+            assertTrue(q.offer(new PDelay(i)));
         assertFalse(q.isEmpty());
-        assertEquals(NOCAP, q.remainingCapacity());
-	assertEquals(n, q.size());
+        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
+        assertEquals(n, q.size());
+        assertEquals(new PDelay(0), q.peek());
         return q;
     }
- 
+
     /**
-     *
+     * A new queue has unbounded capacity
      */
     public void testConstructor1() {
-        assertEquals(NOCAP, new DelayQueue().remainingCapacity());
+        assertEquals(Integer.MAX_VALUE, new DelayQueue().remainingCapacity());
     }
 
     /**
-     *
+     * Initializing from null Collection throws NPE
      */
     public void testConstructor3() {
         try {
-            DelayQueue q = new DelayQueue(null);
+            new DelayQueue(null);
             shouldThrow();
-        }
-        catch (NullPointerException success) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     *
+     * Initializing from Collection of null elements throws NPE
      */
     public void testConstructor4() {
         try {
-            PDelay[] ints = new PDelay[SIZE];
-            DelayQueue q = new DelayQueue(Arrays.asList(ints));
+            new DelayQueue(Arrays.asList(new PDelay[SIZE]));
             shouldThrow();
-        }
-        catch (NullPointerException success) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     *
+     * Initializing from Collection with some null elements throws NPE
      */
     public void testConstructor5() {
+        PDelay[] a = new PDelay[SIZE];
+        for (int i = 0; i < SIZE - 1; ++i)
+            a[i] = new PDelay(i);
         try {
-            PDelay[] ints = new PDelay[SIZE];
-            for (int i = 0; i < SIZE-1; ++i)
-                ints[i] = new PDelay(i);
-            DelayQueue q = new DelayQueue(Arrays.asList(ints));
+            new DelayQueue(Arrays.asList(a));
             shouldThrow();
-        }
-        catch (NullPointerException success) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     *
+     * Queue contains all elements of collection used to initialize
      */
     public void testConstructor6() {
-        try {
-            PDelay[] ints = new PDelay[SIZE];
-            for (int i = 0; i < SIZE; ++i)
-                ints[i] = new PDelay(i);
-            DelayQueue q = new DelayQueue(Arrays.asList(ints));
-            for (int i = 0; i < SIZE; ++i)
-                assertEquals(ints[i], q.poll());
-        }
-        finally {}
+        PDelay[] ints = new PDelay[SIZE];
+        for (int i = 0; i < SIZE; ++i)
+            ints[i] = new PDelay(i);
+        DelayQueue q = new DelayQueue(Arrays.asList(ints));
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(ints[i], q.poll());
     }
 
     /**
-     *
+     * isEmpty is true before add, false after
      */
     public void testEmpty() {
         DelayQueue q = new DelayQueue();
         assertTrue(q.isEmpty());
-        assertEquals(NOCAP, q.remainingCapacity());
+        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
         q.add(new PDelay(1));
         assertFalse(q.isEmpty());
         q.add(new PDelay(2));
@@ -203,35 +197,24 @@ public class DelayQueueTest extends JSR1
     }
 
     /**
-     *
+     * remainingCapacity() always returns Integer.MAX_VALUE
      */
     public void testRemainingCapacity() {
-        DelayQueue q = populatedQueue(SIZE);
+        BlockingQueue q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(NOCAP, q.remainingCapacity());
-            assertEquals(SIZE-i, q.size());
-            q.remove();
+            assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
+            assertEquals(SIZE - i, q.size());
+            assertTrue(q.remove() instanceof PDelay);
         }
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(NOCAP, q.remainingCapacity());
+            assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
             assertEquals(i, q.size());
-            q.add(new PDelay(i));
+            assertTrue(q.add(new PDelay(i)));
         }
     }
 
     /**
-     *
-     */
-    public void testOfferNull() {
-	try {
-            DelayQueue q = new DelayQueue();
-            q.offer(null);
-            shouldThrow();
-        } catch (NullPointerException success) { }   
-    }
-
-    /**
-     *
+     * offer non-null succeeds
      */
     public void testOffer() {
         DelayQueue q = new DelayQueue();
@@ -240,7 +223,7 @@ public class DelayQueueTest extends JSR1
     }
 
     /**
-     *
+     * add succeeds
      */
     public void testAdd() {
         DelayQueue q = new DelayQueue();
@@ -251,371 +234,257 @@ public class DelayQueueTest extends JSR1
     }
 
     /**
-     *
+     * addAll(this) throws IAE
      */
-    public void testAddAll1() {
-        try {
-            DelayQueue q = new DelayQueue();
-            q.addAll(null);
-            shouldThrow();
-        }
-        catch (NullPointerException success) {}
-    }
-    /**
-     *
-     */
-    public void testAddAll2() {
+    public void testAddAllSelf() {
+        DelayQueue q = populatedQueue(SIZE);
         try {
-            DelayQueue q = new DelayQueue();
-            PDelay[] ints = new PDelay[SIZE];
-            q.addAll(Arrays.asList(ints));
+            q.addAll(q);
             shouldThrow();
-        }
-        catch (NullPointerException success) {}
+        } catch (IllegalArgumentException success) {}
     }
+
     /**
-     *
+     * addAll of a collection with any null elements throws NPE after
+     * possibly adding some elements
      */
     public void testAddAll3() {
+        DelayQueue q = new DelayQueue();
+        PDelay[] a = new PDelay[SIZE];
+        for (int i = 0; i < SIZE - 1; ++i)
+            a[i] = new PDelay(i);
         try {
-            DelayQueue q = new DelayQueue();
-            PDelay[] ints = new PDelay[SIZE];
-            for (int i = 0; i < SIZE-1; ++i)
-                ints[i] = new PDelay(i);
-            q.addAll(Arrays.asList(ints));
+            q.addAll(Arrays.asList(a));
             shouldThrow();
-        }
-        catch (NullPointerException success) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     *
+     * Queue contains all elements of successful addAll
      */
     public void testAddAll5() {
-        try {
-            PDelay[] empty = new PDelay[0];
-            PDelay[] ints = new PDelay[SIZE];
-            for (int i = SIZE-1; i >= 0; --i)
-                ints[i] = new PDelay(i);
-            DelayQueue q = new DelayQueue();
-            assertFalse(q.addAll(Arrays.asList(empty)));
-            assertTrue(q.addAll(Arrays.asList(ints)));
-            for (int i = 0; i < SIZE; ++i)
-                assertEquals(ints[i], q.poll());
-        }
-        finally {}
+        PDelay[] empty = new PDelay[0];
+        PDelay[] ints = new PDelay[SIZE];
+        for (int i = SIZE - 1; i >= 0; --i)
+            ints[i] = new PDelay(i);
+        DelayQueue q = new DelayQueue();
+        assertFalse(q.addAll(Arrays.asList(empty)));
+        assertTrue(q.addAll(Arrays.asList(ints)));
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(ints[i], q.poll());
     }
 
     /**
-     *
-     */
-     public void testPutNull() {
-	try {
-            DelayQueue q = new DelayQueue();
-            q.put(null);
-            shouldThrow();
-        } 
-        catch (NullPointerException success){
-	}   
-     }
-
-    /**
-     *
+     * all elements successfully put are contained
      */
-     public void testPut() {
-         try {
-             DelayQueue q = new DelayQueue();
-             for (int i = 0; i < SIZE; ++i) {
-                 PDelay I = new PDelay(i);
-                 q.put(I);
-                 assertTrue(q.contains(I));
-             }
-             assertEquals(SIZE, q.size());
-         }
-         finally {
+    public void testPut() {
+        DelayQueue q = new DelayQueue();
+        for (int i = 0; i < SIZE; ++i) {
+            PDelay x = new PDelay(i);
+            q.put(x);
+            assertTrue(q.contains(x));
         }
+        assertEquals(SIZE, q.size());
     }
 
     /**
-     *
+     * put doesn't block waiting for take
      */
-    public void testPutWithTake() {
+    public void testPutWithTake() throws InterruptedException {
         final DelayQueue q = new DelayQueue();
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    int added = 0;
-                    try {
-                        q.put(new PDelay(0));
-                        ++added;
-                        q.put(new PDelay(0));
-                        ++added;
-                        q.put(new PDelay(0));
-                        ++added;
-                        q.put(new PDelay(0));
-                        ++added;
-                        threadAssertTrue(added == 4);
-                    } finally {
-                    }
-                }
-            });
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            q.take();
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            unexpectedException();
-        }
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                q.put(new PDelay(0));
+                q.put(new PDelay(0));
+                q.put(new PDelay(0));
+                q.put(new PDelay(0));
+            }});
+
+        awaitTermination(t);
+        assertEquals(4, q.size());
     }
 
     /**
-     *
+     * timed offer does not time out
      */
-    public void testTimedOffer() {
+    public void testTimedOffer() throws InterruptedException {
         final DelayQueue q = new DelayQueue();
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        q.put(new PDelay(0));
-                        q.put(new PDelay(0));
-                        threadAssertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-                        threadAssertTrue(q.offer(new PDelay(0), LONG_DELAY_MS, TimeUnit.MILLISECONDS));
-                    } finally { }
-                }
-            });
-        
-        try {
-            t.start();
-            Thread.sleep(SMALL_DELAY_MS);
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            unexpectedException();
-        }
-    }
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                q.put(new PDelay(0));
+                q.put(new PDelay(0));
+                assertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, MILLISECONDS));
+                assertTrue(q.offer(new PDelay(0), LONG_DELAY_MS, MILLISECONDS));
+            }});
 
-    /**
-     *
-     */
-    public void testTake() {
-	try {
-            DelayQueue q = populatedQueue(SIZE);
-            for (int i = 0; i < SIZE; ++i) {
-                assertEquals(new PDelay(i), ((PDelay)q.take()));
-            }
-        } catch (InterruptedException e){
-	    unexpectedException();
-	}   
+        awaitTermination(t);
     }
 
     /**
-     *
+     * take retrieves elements in priority order
      */
-    public void testTakeFromEmpty() {
-        final DelayQueue q = new DelayQueue();
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        q.take();
-			threadShouldThrow();
-                    } catch (InterruptedException success){ }                
-                }
-            });
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            unexpectedException();
+    public void testTake() throws InterruptedException {
+        DelayQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(new PDelay(i), q.take());
         }
     }
 
     /**
-     *
-     */
-    public void testBlockingTake() {
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        DelayQueue q = populatedQueue(SIZE);
-                        for (int i = 0; i < SIZE; ++i) {
-                            threadAssertEquals(new PDelay(i), ((PDelay)q.take()));
-                        }
-                        q.take();
-                        threadShouldThrow();
-                    } catch (InterruptedException success){
-                    }   
-                }});
-        t.start();
-        try { 
-           Thread.sleep(SHORT_DELAY_MS); 
-           t.interrupt();
-           t.join();
-        }
-        catch (InterruptedException ie) {
-	    unexpectedException();
-        }
-    }
+     * Take removes existing elements until empty, then blocks interruptibly
+     */
+    public void testBlockingTake() throws InterruptedException {
+        final DelayQueue 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(new PDelay(i), ((PDelay)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());
+            }});
 
+        await(pleaseInterrupt);
+        assertThreadBlocks(t, Thread.State.WAITING);
+        t.interrupt();
+        awaitTermination(t);
+    }
 
     /**
-     *
+     * poll succeeds unless empty
      */
     public void testPoll() {
         DelayQueue q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(new PDelay(i), ((PDelay)q.poll()));
+            assertEquals(new PDelay(i), q.poll());
         }
-	assertNull(q.poll());
+        assertNull(q.poll());
     }
 
     /**
-     *
+     * timed poll with zero timeout succeeds when non-empty, else times out
      */
-    public void testTimedPoll0() {
-        try {
-            DelayQueue q = populatedQueue(SIZE);
-            for (int i = 0; i < SIZE; ++i) {
-                assertEquals(new PDelay(i), ((PDelay)q.poll(0, TimeUnit.MILLISECONDS)));
-            }
-            assertNull(q.poll(0, TimeUnit.MILLISECONDS));
-        } catch (InterruptedException e){
-	    unexpectedException();
-	}   
+    public void testTimedPoll0() throws InterruptedException {
+        DelayQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(new PDelay(i), q.poll(0, MILLISECONDS));
+        }
+        assertNull(q.poll(0, MILLISECONDS));
     }
 
     /**
-     *
+     * timed poll with nonzero timeout succeeds when non-empty, else times out
      */
-    public void testTimedPoll() {
-        try {
-            DelayQueue q = populatedQueue(SIZE);
-            for (int i = 0; i < SIZE; ++i) {
-                assertEquals(new PDelay(i), ((PDelay)q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)));
-            }
-            assertNull(q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-        } catch (InterruptedException e){
-	    unexpectedException();
-	}   
-    }
-
-    /**
-     *
-     */
-    public void testInterruptedTimedPoll() {
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        DelayQueue q = populatedQueue(SIZE);
-                        for (int i = 0; i < SIZE; ++i) {
-                            threadAssertEquals(new PDelay(i), ((PDelay)q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)));
-                        }
-                        threadAssertNull(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) {
-	    unexpectedException();
+    public void testTimedPoll() throws InterruptedException {
+        DelayQueue q = populatedQueue(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            long startTime = System.nanoTime();
+            assertEquals(new PDelay(i), 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);
     }
 
     /**
-     *
+     * Interrupted timed poll throws InterruptedException instead of
+     * returning timeout status
      */
-    public void testTimedPollWithOffer() {
-        final DelayQueue q = new DelayQueue();
-        Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-                        threadAssertNull(q.poll(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-                        q.poll(LONG_DELAY_MS, TimeUnit.MILLISECONDS);
-                        q.poll(LONG_DELAY_MS, TimeUnit.MILLISECONDS);
-			threadFail("Should block");
-                    } catch (InterruptedException success) { }                
-                }
-            });
-        try {
-            t.start();
-            Thread.sleep(SMALL_DELAY_MS);
-            assertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
-            t.interrupt();
-            t.join();
-        } catch (Exception e){
-            unexpectedException();
-        }
-    }  
+    public void testInterruptedTimedPoll() throws InterruptedException {
+        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
+        final DelayQueue q = populatedQueue(SIZE);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                long startTime = System.nanoTime();
+                for (int i = 0; i < SIZE; i++)
+                    assertEquals(new PDelay(i),
+                                 ((PDelay)q.poll(LONG_DELAY_MS, MILLISECONDS)));
+
+                Thread.currentThread().interrupt();
+                try {
+                    q.poll(LONG_DELAY_MS, MILLISECONDS);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
 
+                pleaseInterrupt.countDown();
+                try {
+                    q.poll(LONG_DELAY_MS, MILLISECONDS);
+                    shouldThrow();
+                } catch (InterruptedException success) {}
+                assertFalse(Thread.interrupted());
+
+                assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
+            }});
+
+        await(pleaseInterrupt);
+        assertThreadBlocks(t, Thread.State.TIMED_WAITING);
+        t.interrupt();
+        awaitTermination(t);
+        checkEmpty(q);
+    }
 
     /**
-     *
+     * peek returns next element, or null if empty
      */
     public void testPeek() {
         DelayQueue q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(new PDelay(i), ((PDelay)q.peek()));
-            q.poll();
-            assertTrue(q.peek() == null ||
-                       i != ((PDelay)q.peek()).intValue());
+            assertEquals(new PDelay(i), q.peek());
+            assertEquals(new PDelay(i), q.poll());
+            if (q.isEmpty())
+                assertNull(q.peek());
+            else
+                assertFalse(new PDelay(i).equals(q.peek()));
         }
-	assertNull(q.peek());
+        assertNull(q.peek());
     }
 
     /**
-     *
+     * element returns next element, or throws NSEE if empty
      */
     public void testElement() {
         DelayQueue q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(new PDelay(i), ((PDelay)q.element()));
+            assertEquals(new PDelay(i), q.element());
             q.poll();
         }
         try {
             q.element();
             shouldThrow();
-        }
-        catch (NoSuchElementException success) {}
+        } catch (NoSuchElementException success) {}
     }
 
     /**
-     *
+     * remove removes next element, or throws NSEE if empty
      */
     public void testRemove() {
         DelayQueue q = populatedQueue(SIZE);
         for (int i = 0; i < SIZE; ++i) {
-            assertEquals(new PDelay(i), ((PDelay)q.remove()));
+            assertEquals(new PDelay(i), q.remove());
         }
         try {
             q.remove();
             shouldThrow();
-        } catch (NoSuchElementException success){
-	}   
+        } catch (NoSuchElementException success) {}
     }
 
     /**
-     *
-     */
-    public void testRemoveElement() {
-        DelayQueue q = populatedQueue(SIZE);
-        for (int i = 1; i < SIZE; i+=2) {
-            assertTrue(q.remove(new PDelay(i)));
-        }
-        for (int i = 0; i < SIZE; i+=2) {
-            assertTrue(q.remove(new PDelay(i)));
-            assertFalse(q.remove(new PDelay(i+1)));
-        }
-        assertTrue(q.isEmpty());
-    }
-	
-    /**
-     *
+     * contains(x) reports true when elements added but not yet removed
      */
     public void testContains() {
         DelayQueue q = populatedQueue(SIZE);
@@ -627,22 +496,24 @@ public class DelayQueueTest extends JSR1
     }
 
     /**
-     *
+     * clear removes all elements
      */
     public void testClear() {
         DelayQueue q = populatedQueue(SIZE);
         q.clear();
         assertTrue(q.isEmpty());
         assertEquals(0, q.size());
-        assertEquals(NOCAP, q.remainingCapacity());
-        q.add(new PDelay(1));
+        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
+        PDelay x = new PDelay(1);
+        q.add(x);
         assertFalse(q.isEmpty());
+        assertTrue(q.contains(x));
         q.clear();
         assertTrue(q.isEmpty());
     }
 
     /**
-     *
+     * containsAll(c) is true when c contains a subset of elements
      */
     public void testContainsAll() {
         DelayQueue q = populatedQueue(SIZE);
@@ -656,7 +527,7 @@ public class DelayQueueTest extends JSR1
     }
 
     /**
-     *
+     * retainAll(c) retains only those elements of c and reports true if changed
      */
     public void testRetainAll() {
         DelayQueue q = populatedQueue(SIZE);
@@ -669,171 +540,250 @@ public class DelayQueueTest extends JSR1
                 assertTrue(changed);
 
             assertTrue(q.containsAll(p));
-            assertEquals(SIZE-i, q.size());
+            assertEquals(SIZE - i, q.size());
             p.remove();
         }
     }
 
     /**
-     *
+     * removeAll(c) removes only those elements of c and reports true if changed
      */
     public void testRemoveAll() {
         for (int i = 1; i < SIZE; ++i) {
             DelayQueue q = populatedQueue(SIZE);
             DelayQueue p = populatedQueue(i);
             assertTrue(q.removeAll(p));
-            assertEquals(SIZE-i, q.size());
+            assertEquals(SIZE - i, q.size());
             for (int j = 0; j < i; ++j) {
-                PDelay I = (PDelay)(p.remove());
-                assertFalse(q.contains(I));
+                PDelay x = (PDelay)(p.remove());
+                assertFalse(q.contains(x));
             }
         }
     }
 
     /**
-     *
+     * toArray contains all elements
      */
-    public void testToArray() {
+    public void testToArray() throws InterruptedException {
         DelayQueue q = populatedQueue(SIZE);
-	Object[] o = q.toArray();
+        Object[] o = q.toArray();
         Arrays.sort(o);
-	try {
-	for(int i = 0; i < o.length; i++)
-	    assertEquals(o[i], q.take());
-	} catch (InterruptedException e){
-	    unexpectedException();
-	}    
+        for (int i = 0; i < o.length; i++)
+            assertSame(o[i], q.take());
     }
 
     /**
-     *
+     * toArray(a) contains all elements
      */
     public void testToArray2() {
-        DelayQueue q = populatedQueue(SIZE);
-	PDelay[] ints = new PDelay[SIZE];
-	ints = (PDelay[])q.toArray(ints);
+        DelayQueue<PDelay> q = populatedQueue(SIZE);
+        PDelay[] ints = new PDelay[SIZE];
+        PDelay[] array = q.toArray(ints);
+        assertSame(ints, array);
         Arrays.sort(ints);
-	try {
-	    for(int i = 0; i < ints.length; i++)
-		assertEquals(ints[i], q.take());
-	} catch (InterruptedException e){
-	    unexpectedException();
-	}    
+        for (int i = 0; i < ints.length; i++)
+            assertSame(ints[i], q.remove());
+    }
+
+    /**
+     * toArray(incompatible array type) throws ArrayStoreException
+     */
+    public void testToArray1_BadArg() {
+        DelayQueue q = populatedQueue(SIZE);
+        try {
+            q.toArray(new String[10]);
+            shouldThrow();
+        } catch (ArrayStoreException success) {}
     }
-    
+
     /**
-     *
+     * iterator iterates through all elements
      */
     public void testIterator() {
         DelayQueue q = populatedQueue(SIZE);
         int i = 0;
-	Iterator it = q.iterator();
-        while(it.hasNext()) {
+        Iterator it = q.iterator();
+        while (it.hasNext()) {
             assertTrue(q.contains(it.next()));
             ++i;
         }
         assertEquals(i, SIZE);
+        assertIteratorExhausted(it);
     }
 
     /**
-     *
+     * iterator of empty collection has no elements
      */
-    public void testIteratorRemove () {
+    public void testEmptyIterator() {
+        assertIteratorExhausted(new DelayQueue().iterator());
+    }
 
+    /**
+     * iterator.remove removes current element
+     */
+    public void testIteratorRemove() {
         final DelayQueue q = new DelayQueue();
-
         q.add(new PDelay(2));
         q.add(new PDelay(1));
         q.add(new PDelay(3));
-
         Iterator it = q.iterator();
         it.next();
         it.remove();
-
         it = q.iterator();
-        assertEquals(it.next(), new PDelay(2));
-        assertEquals(it.next(), new PDelay(3));
+        assertEquals(new PDelay(2), it.next());
+        assertEquals(new PDelay(3), it.next());
         assertFalse(it.hasNext());
     }
 
-
     /**
-     *
+     * toString contains toStrings of elements
      */
     public void testToString() {
         DelayQueue q = populatedQueue(SIZE);
         String s = q.toString();
-        for (int i = 0; i < SIZE; ++i) {
-            assertTrue(s.indexOf(String.valueOf(Integer.MIN_VALUE+i)) >= 0);
-        }
-    }        
+        for (Object e : q)
+            assertTrue(s.contains(e.toString()));
+    }
 
     /**
-     *
+     * timed poll transfers elements across Executor tasks
      */
     public void testPollInExecutor() {
-
         final DelayQueue q = new DelayQueue();
+        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
+        final ExecutorService executor = Executors.newFixedThreadPool(2);
+        try (PoolCleaner cleaner = cleaner(executor)) {
+            executor.execute(new CheckedRunnable() {
+                public void realRun() throws InterruptedException {
+                    assertNull(q.poll());
+                    threadsStarted.await();
+                    assertNotNull(q.poll(LONG_DELAY_MS, MILLISECONDS));
+                    checkEmpty(q);
+                }});
 
-        ExecutorService executor = Executors.newFixedThreadPool(2);
+            executor.execute(new CheckedRunnable() {
+                public void realRun() throws InterruptedException {
+                    threadsStarted.await();
+                    q.put(new PDelay(1));
+                }});
+        }
+    }
 
-        executor.execute(new Runnable() {
-            public void run() {
-                threadAssertNull(q.poll());
-                try {
-                    threadAssertTrue(null != q.poll(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS));
-                    threadAssertTrue(q.isEmpty());
-                }
-                catch (InterruptedException e) {
-                    threadUnexpectedException();
-                }
-            }
-        });
+    /**
+     * Delayed actions do not occur until their delay elapses
+     */
+    public void testDelay() throws InterruptedException {
+        DelayQueue<NanoDelay> q = new DelayQueue<>();
+        for (int i = 0; i < SIZE; ++i)
+            q.add(new NanoDelay(1000000L * (SIZE - i)));
+
+        long last = 0;
+        for (int i = 0; i < SIZE; ++i) {
+            NanoDelay e = q.take();
+            long tt = e.getTriggerTime();
+            assertTrue(System.nanoTime() - tt >= 0);
+            if (i != 0)
+                assertTrue(tt >= last);
+            last = tt;
+        }
+        assertTrue(q.isEmpty());
+    }
 
-        executor.execute(new Runnable() {
-            public void run() {
-                try {
-                    Thread.sleep(SHORT_DELAY_MS);
-                    q.put(new PDelay(1));
-                }
-                catch (InterruptedException e) {
-                    threadUnexpectedException();
-                }
-            }
-        });
-        
-        joinPool(executor);
+    /**
+     * peek of a non-empty queue returns non-null even if not expired
+     */
+    public void testPeekDelayed() {
+        DelayQueue q = new DelayQueue();
+        q.add(new NanoDelay(Long.MAX_VALUE));
+        assertNotNull(q.peek());
+    }
 
+    /**
+     * poll of a non-empty queue returns null if no expired elements.
+     */
+    public void testPollDelayed() {
+        DelayQueue q = new DelayQueue();
+        q.add(new NanoDelay(Long.MAX_VALUE));
+        assertNull(q.poll());
     }
 
+    /**
+     * timed poll of a non-empty queue returns null if no expired elements.
+     */
+    public void testTimedPollDelayed() throws InterruptedException {
+        DelayQueue q = new DelayQueue();
+        q.add(new NanoDelay(LONG_DELAY_MS * 1000000L));
+        long startTime = System.nanoTime();
+        assertNull(q.poll(timeoutMillis(), MILLISECONDS));
+        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
+    }
 
     /**
-     *
+     * drainTo(c) empties queue into another collection c
      */
-    public void testDelay() {
+    public void testDrainTo() {
         DelayQueue q = new DelayQueue();
-        NanoDelay[] elements = new NanoDelay[SIZE];
-        for (int i = 0; i < SIZE; ++i) {
-            elements[i] = new NanoDelay(1000000000L + 1000000L * (SIZE - i));
-        }
+        PDelay[] elems = new PDelay[SIZE];
         for (int i = 0; i < SIZE; ++i) {
-            q.add(elements[i]);
+            elems[i] = new PDelay(i);
+            q.add(elems[i]);
         }
+        ArrayList l = new ArrayList();
+        q.drainTo(l);
+        assertEquals(0, q.size());
+        for (int i = 0; i < SIZE; ++i)
+            assertEquals(elems[i], l.get(i));
+        q.add(elems[0]);
+        q.add(elems[1]);
+        assertFalse(q.isEmpty());
+        assertTrue(q.contains(elems[0]));
+        assertTrue(q.contains(elems[1]));
+        l.clear();
+        q.drainTo(l);
+        assertEquals(0, q.size());
+        assertEquals(2, l.size());
+        for (int i = 0; i < 2; ++i)
+            assertEquals(elems[i], l.get(i));
+    }
 
-        try {
-            long last = 0;
-            for (int i = 0; i < SIZE; ++i) {
-                NanoDelay e = (NanoDelay)(q.take());
-                long tt = e.getTriggerTime();
-                assertTrue(tt <= System.nanoTime());
-                if (i != 0) 
-                    assertTrue(tt >= last);
-                last = tt;
-            }
-        }
-        catch(InterruptedException ie) {
-            unexpectedException();
+    /**
+     * drainTo empties queue
+     */
+    public void testDrainToWithActivePut() throws InterruptedException {
+        final DelayQueue q = populatedQueue(SIZE);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() {
+                q.put(new PDelay(SIZE + 1));
+            }});
+
+        t.start();
+        ArrayList l = new ArrayList();
+        q.drainTo(l);
+        assertTrue(l.size() >= SIZE);
+        t.join();
+        assertTrue(q.size() + l.size() >= SIZE);
+    }
+
+    /**
+     * drainTo(c, n) empties first min(n, size) elements of queue into c
+     */
+    public void testDrainToN() {
+        for (int i = 0; i < SIZE + 2; ++i) {
+            DelayQueue q = populatedQueue(SIZE);
+            ArrayList l = new ArrayList();
+            q.drainTo(l, i);
+            int k = (i < SIZE) ? i : SIZE;
+            assertEquals(SIZE - k, q.size());
+            assertEquals(k, l.size());
         }
     }
 
+    /**
+     * remove(null), contains(null) always return false
+     */
+    public void testNeverContainsNull() {
+        Collection<?> q = populatedQueue(SIZE);
+        assertFalse(q.contains(null));
+        assertFalse(q.remove(null));
+    }
 }