test/loops/DequeBash.java

/*
 * Written by Josh Bloch of Google Inc. and released to the public domain,
 * as explained at http://creativecommons.org/publicdomain/zero/1.0/.
 */

import java.io.*;
import java.util.*;

/**
 * Interface-based Deque tester.  This test currently makes three
 * assumptions about the implementation under test:
 *
 *   1) It has no size limitation.
 *   2) It implements Serializable.
 *   3) It has a conventional (Collection) constructor.
 *
 * All of these assumptions could be relaxed.
 */
public class DequeBash {
    static int seed = 7;
    static int nextTail =  0;
    static int nextHead = -1;
    static int size() { return nextTail - nextHead - 1; }

    static int random() {
        int r = seed;
        r ^= r << 13;   // xorshift
        r ^= r >>> 17;
        return seed = r ^ (r << 5);
    }

    static int random(int bound) {
        return (random() & 0x7fffffff) % bound;
    }
    
    public static void main(String[] args) throws Exception {
        Class<?> cls = Class.forName(args[0]);
        long startTime = System.nanoTime();
        for (int j = 0; j < 200; ++j) {
            @SuppressWarnings("unchecked")
            Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
            nextTail =  0;
            nextHead = -1;
            mainTest(deque, (random() & ((1 << 20) - 1)));
            if (deque.isEmpty()) System.out.print(" ");
            if ((j % 10) == 9) System.out.print(".");
        }
        long now = System.nanoTime();
        long elapsedTimeMillis = (now - startTime) / (1000L * 1000L);
        System.out.printf("\ntotal time %d ms\n", elapsedTimeMillis);
        
    }

    static void mainTest(Deque<Integer> deque, int n) throws Exception {
        /*
         * Perform a random sequence of operations, keeping contiguous
         * sequence of integers on the deque.
         */
        for (int i = 0; i < n; i++) {
            sizeTests(deque);
            randomOp(deque);

            // Test iterator occasionally
            if ((i & 1023) == 0) {
                testIter(deque);
                testDescendingIter(deque);
            }

            // Test serialization and copying
            if ((i & 4095) == 0) {
                testEqual(deque, serialClone(deque));
                testEqual(deque, copyConstructorClone(deque));
            }

            // Test fancy removal stuff once in a blue moon
            if ((i & 8191) == 0)
                testRemove(deque);
        }

        // Stupid tests for clear, toString
        deque.clear();
        testEmpty(deque);
        Collection<Integer> c = Arrays.asList(1, 2, 3);
        deque.addAll(c);
        if (!deque.toString().equals("[1, 2, 3]"))
            throw new Exception("Deque.toString():  " + deque.toString());
    }

    static void testIter(Deque<Integer> deque) throws Exception {
        int next = nextHead + 1;
        int count = 0;
        for (int j : deque) {
            if (j != next++)
                throw new Exception("Element "+ j + " != " + (next-1));
            count++;
        }
        if (count != size())
            throw new Exception("Count " + count + " != " + size());
    }

    static void testDescendingIter(Deque<Integer> deque) throws Exception {
        int next = deque.size() + nextHead;
        int count = 0;
        for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) {
            int j = it.next();
            if (j != next--)
                throw new Exception("Element "+ j + " != " + (next-1));
            count++;
        }
        if (count != size())
            throw new Exception("Count " + count + " != " + size());
    }

    static void sizeTests(Deque<Integer> deque) throws Exception {
        if (deque.size() != size())
            throw new Exception("Size: " + deque.size() +
                                ", expecting " + size());
        if (deque.isEmpty() != (size() == 0))
            throw new Exception(
                                "IsEmpty " + deque.isEmpty() + ", size " + size());
        // Check head and tail
        if (size() == 0)
            testEmpty(deque);
        else
            nonEmptyTest(deque);

    }

    static void nonEmptyTest(Deque<Integer> deque) throws Exception {
        if (deque.getFirst() != nextHead + 1)
            throw new Exception("getFirst got: " +
                                deque.getFirst() + " expecting " + (nextHead + 1));
        if (deque.element() != nextHead + 1)
            throw new Exception("element got: " + deque.element() +
                                " expecting " + (nextHead + 1));
        if (deque.peekFirst() != nextHead + 1)
            throw new Exception("peekFirst got: "+deque.peekFirst() +
                                " expecting " + (nextHead + 1));
        if (deque.peek() != nextHead + 1)
            throw new Exception("peek got: " +  deque.peek() +
                                " expecting " + (nextHead + 1));

        if (deque.peekLast() != nextTail - 1)
            throw new Exception("peekLast got: " + deque.peekLast() +
                                " expecting " + (nextTail - 1));
        if (deque.getLast() != nextTail - 1)
            throw new Exception("getLast got: " +
                                deque.getLast() + " expecting " + (nextTail - 1));
    }

    static void randomOp(Deque<Integer> deque) throws Exception {

        // Perform a random operation
        switch (random() & 3) {
        case 0:
            switch (random() & 3) {
            case 0: deque.addLast(nextTail++);   break;
            case 1: deque.offerLast(nextTail++); break;
            case 2: deque.offer(nextTail++);     break;
            case 3: deque.add(nextTail++);       break;
            default: throw new Exception("How'd we get here");
            }
            break;
        case 1:
            if (size() == 0) {
                int result = 666;
                boolean threw = false;
                try {
                    switch (random(3)) {
                    case 0: result = deque.removeFirst(); break;
                    case 1: result = deque.remove();      break;
                    case 2: result = deque.pop();         break;
                    default: throw new Exception("How'd we get here");
                    }
                } catch (NoSuchElementException e) {
                    threw = true;
                }
                if (!threw)
                    throw new Exception("Remove-no exception: " + result);
            } else { // deque nonempty
                int result = -1;
                switch (random(5)) {
                case 0: result = deque.removeFirst(); break;
                case 1: result = deque.remove();      break;
                case 2: result = deque.pop();         break;
                case 3: result = deque.pollFirst();   break;
                case 4: result = deque.poll();        break;
                default: throw new Exception("How'd we get here");
                }
                if (result != ++nextHead)
                    throw new Exception(
                                        "Removed "+ result + " expecting "+(nextHead - 1));
            }
            break;
        case 2:
            switch (random(3)) {
            case 0: deque.addFirst(nextHead--);   break;
            case 1: deque.offerFirst(nextHead--); break;
            case 2: deque.push(nextHead--);       break;
            default: throw new Exception("How'd we get here");
            }
            break;
        case 3:
            if (size() == 0) {
                int result = -1;
                boolean threw = false;
                try {
                    result = deque.removeLast();
                } catch (NoSuchElementException e) {
                    threw = true;
                }
                if (!threw)
                    throw new Exception("Remove-no exception: " + result);
            } else { // deque nonempty
                int result = ((random() & 1) == 0 ?
                              deque.removeLast() : deque.pollLast());
                if (result != --nextTail)
                    throw new Exception(
                        "Removed "+ result + " expecting "+(nextTail + 1));
            }
            break;
        default:
            throw new Exception("How'd we get here");
        }
    }

    private static void testEqual(Deque<Integer> d1, Deque<Integer> d2)
        throws Exception
    {
        if (d1.size() != d2.size())
            throw new Exception("Size " + d1.size() + " != " + d2.size());
        Iterator<Integer> it = d2.iterator();
        for (int i : d1) {
            int j = it.next();
            if (j != i)
                throw new Exception("Element " + j + " != " + i);
        }

        for (int i : d1)
            if (!d2.contains(i))
                throw new Exception("d2 doesn't contain " + i);
        for (int i : d2)
            if (!d1.contains(i))
                throw new Exception("d2 doesn't contain " + i);

        if (d1.contains(Integer.MIN_VALUE))
            throw new Exception("d2 contains Integer.MIN_VALUE");
        if (d2.contains(Integer.MIN_VALUE))
            throw new Exception("d2 contains Integer.MIN_VALUE");
        if (d1.contains(null))
            throw new Exception("d1 contains null");
        if (d2.contains(null))
            throw new Exception("d2 contains null");

        if (!d1.containsAll(d2))
            throw new Exception("d1 doesn't contain all of d2");
        if (!d2.containsAll(d1))
            throw new Exception("d2 doesn't contain all of d1");
        Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE);
        if (d1.containsAll(c))
            throw new Exception("d1 contains all of {Integer.MIN_VALUE }");
        if (d2.containsAll(c))
            throw new Exception("d2 contains all of {Integer.MIN_VALUE }");
    }

    @SuppressWarnings("unchecked")
    private static <T> T copyConstructorClone(T o) throws Exception {
        return (T) o.getClass().getConstructor(Collection.class).newInstance(o);
    }

    @SuppressWarnings("unchecked")
    private static <T> T serialClone(T o) throws Exception {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        oos.writeObject(o);
        oos.flush();
        oos.close();
        ByteArrayInputStream bin =
            new ByteArrayInputStream(bos.toByteArray());
        ObjectInputStream ois = new ObjectInputStream(bin);
            return (T) ois.readObject();
    }

    private static void testRemove(Deque<Integer> deque) throws Exception {
        Deque<Integer> copy = ((random() & 1) == 0) ?
            copyConstructorClone(deque) :
            serialClone(deque);

        int numRemoved = 0;
        for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) {
            if ((it.next() & 1) == 0) {
                it.remove();
                numRemoved++;
            }
        }

        if (copy.size() + numRemoved != size())
            throw new Exception((copy.size() + numRemoved) + " != " + size());
        for (int i : copy)
            if ((i & 1) == 0)
                throw new Exception("Even number still present: " + i);

        List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0]));
        Collections.shuffle(elements);
        for (int e : elements) {
            if (!copy.contains(e))
                throw new Exception(e + " missing.");

            boolean removed = false;
            switch (random(3)) {
                case 0:  removed = copy.remove(e);                break;
                case 1:  removed = copy.removeFirstOccurrence(e); break;
                case 2:  removed = copy.removeLastOccurrence(e);  break;
                default: throw new Exception("How'd we get here");
            }
            if (!removed)
                throw new Exception(e + " not removed.");

            if (copy.contains(e))
                throw new Exception(e + " present after removal.");
        }

        testEmpty(copy);

        copy = copyConstructorClone(deque);
        copy.retainAll(deque);
        testEqual(deque, copy);
        copy.removeAll(deque);
        testEmpty(copy);
    }

    static boolean checkedThrows;

    private static void testEmpty(Deque<Integer> deque) throws Exception {
        if (!deque.isEmpty())
            throw new Exception("Deque isn't empty");
        if (deque.size() != 0)
            throw new Exception("Deque size isn't zero");
        if (!(deque.pollFirst() == null))
            throw new Exception("pollFirst lies");
        if (!(deque.poll() == null))
            throw new Exception("poll lies");
        if (!(deque.peekFirst() == null))
            throw new Exception("peekFirst lies");
        if (!(deque.peek() == null))
            throw new Exception("peek lies");
        if (!(deque.pollLast() == null))
            throw new Exception("pollLast lies");
        if (!(deque.peekLast() == null))
            throw new Exception("peekLast lies");

        if (!checkedThrows) {
            checkedThrows = true;
            boolean threw = false;
            int result = 666;
            try {
                result = ((random() & 1) == 0 ?
                          deque.getFirst() : deque.element());
            } catch (NoSuchElementException e) {
                threw = true;
            }
            if (!threw)
                throw new Exception("getFirst-no exception: "+result);
            threw = false;
            try {
                result = deque.getLast();
            } catch (NoSuchElementException e) {
                threw = true;
            }
            if (!threw)
                throw new Exception("getLast-no exception: "+result);
        }

    }
}
Revision:	1.13
Committed:	Sat Oct 22 19:30:48 2016 UTC (7 years, 6 months ago) by dl
Branch:	MAIN
Changes since 1.12:	+16 -19 lines
Log Message:	longer randomized tests
#	User	Rev	Content
1	dl	1.1	/*
2			* Written by Josh Bloch of Google Inc. and released to the public domain,
3	jsr166	1.7	* as explained at http://creativecommons.org/publicdomain/zero/1.0/.
4	dl	1.1	*/
5
6	jsr166	1.10	import java.io.*;
7	dl	1.1	import java.util.*;
8
9			/**
10			* Interface-based Deque tester. This test currently makes three
11			* assumptions about the implementation under test:
12			*
13			* 1) It has no size limitation.
14			* 2) It implements Serializable.
15			* 3) It has a conventional (Collection) constructor.
16			*
17			* All of these assumptions could be relaxed.
18			*/
19			public class DequeBash {
20			static int seed = 7;
21			static int nextTail = 0;
22			static int nextHead = -1;
23			static int size() { return nextTail - nextHead - 1; }
24
25	dl	1.13	static int random() {
26			int r = seed;
27			r ^= r << 13; // xorshift
28			r ^= r >>> 17;
29			return seed = r ^ (r << 5);
30	dl	1.1	}
31
32	dl	1.13	static int random(int bound) {
33			return (random() & 0x7fffffff) % bound;
34	dl	1.1	}
35	dl	1.13
36	jsr166	1.9	public static void main(String[] args) throws Exception {
37	jsr166	1.6	Class<?> cls = Class.forName(args[0]);
38	dl	1.13	long startTime = System.nanoTime();
39			for (int j = 0; j < 200; ++j) {
40	jsr166	1.6	@SuppressWarnings("unchecked")
41	dl	1.1	Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
42			nextTail = 0;
43			nextHead = -1;
44	dl	1.13	mainTest(deque, (random() & ((1 << 20) - 1)));
45	dl	1.1	if (deque.isEmpty()) System.out.print(" ");
46	dl	1.13	if ((j % 10) == 9) System.out.print(".");
47	dl	1.1	}
48	dl	1.13	long now = System.nanoTime();
49			long elapsedTimeMillis = (now - startTime) / (1000L * 1000L);
50			System.out.printf("\ntotal time %d ms\n", elapsedTimeMillis);
51
52	dl	1.1	}
53
54			static void mainTest(Deque<Integer> deque, int n) throws Exception {
55			/*
56			* Perform a random sequence of operations, keeping contiguous
57			* sequence of integers on the deque.
58			*/
59			for (int i = 0; i < n; i++) {
60			sizeTests(deque);
61			randomOp(deque);
62
63			// Test iterator occasionally
64	dl	1.2	if ((i & 1023) == 0) {
65	dl	1.1	testIter(deque);
66	dl	1.2	testDescendingIter(deque);
67			}
68	dl	1.1
69			// Test serialization and copying
70			if ((i & 4095) == 0) {
71	jsr166	1.6	testEqual(deque, serialClone(deque));
72			testEqual(deque, copyConstructorClone(deque));
73	dl	1.1	}
74	jsr166	1.3
75	dl	1.1	// Test fancy removal stuff once in a blue moon
76			if ((i & 8191) == 0)
77			testRemove(deque);
78	jsr166	1.8	}
79	dl	1.1
80			// Stupid tests for clear, toString
81			deque.clear();
82			testEmpty(deque);
83			Collection<Integer> c = Arrays.asList(1, 2, 3);
84			deque.addAll(c);
85			if (!deque.toString().equals("[1, 2, 3]"))
86			throw new Exception("Deque.toString(): " + deque.toString());
87			}
88
89	jsr166	1.3	static void testIter(Deque<Integer> deque) throws Exception {
90	dl	1.1	int next = nextHead + 1;
91			int count = 0;
92			for (int j : deque) {
93			if (j != next++)
94			throw new Exception("Element "+ j + " != " + (next-1));
95			count++;
96			}
97			if (count != size())
98			throw new Exception("Count " + count + " != " + size());
99			}
100
101	jsr166	1.3	static void testDescendingIter(Deque<Integer> deque) throws Exception {
102	dl	1.2	int next = deque.size() + nextHead;
103			int count = 0;
104			for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) {
105			int j = it.next();
106			if (j != next--)
107			throw new Exception("Element "+ j + " != " + (next-1));
108			count++;
109			}
110			if (count != size())
111			throw new Exception("Count " + count + " != " + size());
112			}
113
114	dl	1.1	static void sizeTests(Deque<Integer> deque) throws Exception {
115			if (deque.size() != size())
116			throw new Exception("Size: " + deque.size() +
117			", expecting " + size());
118			if (deque.isEmpty() != (size() == 0))
119			throw new Exception(
120			"IsEmpty " + deque.isEmpty() + ", size " + size());
121			// Check head and tail
122	jsr166	1.3	if (size() == 0)
123	dl	1.1	testEmpty(deque);
124	jsr166	1.3	else
125	dl	1.1	nonEmptyTest(deque);
126
127			}
128
129	jsr166	1.3	static void nonEmptyTest(Deque<Integer> deque) throws Exception {
130	dl	1.1	if (deque.getFirst() != nextHead + 1)
131	jsr166	1.3	throw new Exception("getFirst got: " +
132	dl	1.1	deque.getFirst() + " expecting " + (nextHead + 1));
133			if (deque.element() != nextHead + 1)
134			throw new Exception("element got: " + deque.element() +
135			" expecting " + (nextHead + 1));
136			if (deque.peekFirst() != nextHead + 1)
137			throw new Exception("peekFirst got: "+deque.peekFirst() +
138			" expecting " + (nextHead + 1));
139			if (deque.peek() != nextHead + 1)
140			throw new Exception("peek got: " + deque.peek() +
141			" expecting " + (nextHead + 1));
142	jsr166	1.3
143	dl	1.1	if (deque.peekLast() != nextTail - 1)
144			throw new Exception("peekLast got: " + deque.peekLast() +
145			" expecting " + (nextTail - 1));
146			if (deque.getLast() != nextTail - 1)
147	jsr166	1.3	throw new Exception("getLast got: " +
148	dl	1.1	deque.getLast() + " expecting " + (nextTail - 1));
149	jsr166	1.3	}
150
151	dl	1.1	static void randomOp(Deque<Integer> deque) throws Exception {
152	jsr166	1.3
153	dl	1.1	// Perform a random operation
154	jsr166	1.5	switch (random() & 3) {
155	dl	1.1	case 0:
156	jsr166	1.5	switch (random() & 3) {
157	dl	1.1	case 0: deque.addLast(nextTail++); break;
158			case 1: deque.offerLast(nextTail++); break;
159			case 2: deque.offer(nextTail++); break;
160			case 3: deque.add(nextTail++); break;
161			default: throw new Exception("How'd we get here");
162			}
163			break;
164			case 1:
165			if (size() == 0) {
166			int result = 666;
167			boolean threw = false;
168			try {
169	jsr166	1.5	switch (random(3)) {
170	dl	1.1	case 0: result = deque.removeFirst(); break;
171			case 1: result = deque.remove(); break;
172			case 2: result = deque.pop(); break;
173			default: throw new Exception("How'd we get here");
174			}
175	jsr166	1.4	} catch (NoSuchElementException e) {
176	dl	1.1	threw = true;
177			}
178			if (!threw)
179			throw new Exception("Remove-no exception: " + result);
180			} else { // deque nonempty
181			int result = -1;
182	jsr166	1.5	switch (random(5)) {
183	dl	1.1	case 0: result = deque.removeFirst(); break;
184			case 1: result = deque.remove(); break;
185			case 2: result = deque.pop(); break;
186			case 3: result = deque.pollFirst(); break;
187			case 4: result = deque.poll(); break;
188			default: throw new Exception("How'd we get here");
189			}
190			if (result != ++nextHead)
191			throw new Exception(
192			"Removed "+ result + " expecting "+(nextHead - 1));
193			}
194			break;
195			case 2:
196	jsr166	1.5	switch (random(3)) {
197	dl	1.1	case 0: deque.addFirst(nextHead--); break;
198			case 1: deque.offerFirst(nextHead--); break;
199			case 2: deque.push(nextHead--); break;
200			default: throw new Exception("How'd we get here");
201			}
202			break;
203			case 3:
204			if (size() == 0) {
205			int result = -1;
206			boolean threw = false;
207			try {
208			result = deque.removeLast();
209	jsr166	1.4	} catch (NoSuchElementException e) {
210	dl	1.1	threw = true;
211			}
212			if (!threw)
213			throw new Exception("Remove-no exception: " + result);
214			} else { // deque nonempty
215	jsr166	1.4	int result = ((random() & 1) == 0 ?
216	dl	1.1	deque.removeLast() : deque.pollLast());
217			if (result != --nextTail)
218			throw new Exception(
219	jsr166	1.4	"Removed "+ result + " expecting "+(nextTail + 1));
220	dl	1.1	}
221			break;
222			default:
223			throw new Exception("How'd we get here");
224			}
225			}
226
227			private static void testEqual(Deque<Integer> d1, Deque<Integer> d2)
228			throws Exception
229			{
230			if (d1.size() != d2.size())
231			throw new Exception("Size " + d1.size() + " != " + d2.size());
232			Iterator<Integer> it = d2.iterator();
233	jsr166	1.4	for (int i : d1) {
234	dl	1.1	int j = it.next();
235			if (j != i)
236			throw new Exception("Element " + j + " != " + i);
237			}
238
239	jsr166	1.4	for (int i : d1)
240	dl	1.1	if (!d2.contains(i))
241			throw new Exception("d2 doesn't contain " + i);
242	jsr166	1.4	for (int i : d2)
243	dl	1.1	if (!d1.contains(i))
244			throw new Exception("d2 doesn't contain " + i);
245
246			if (d1.contains(Integer.MIN_VALUE))
247			throw new Exception("d2 contains Integer.MIN_VALUE");
248			if (d2.contains(Integer.MIN_VALUE))
249			throw new Exception("d2 contains Integer.MIN_VALUE");
250			if (d1.contains(null))
251			throw new Exception("d1 contains null");
252			if (d2.contains(null))
253			throw new Exception("d2 contains null");
254
255			if (!d1.containsAll(d2))
256			throw new Exception("d1 doesn't contain all of d2");
257			if (!d2.containsAll(d1))
258			throw new Exception("d2 doesn't contain all of d1");
259			Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE);
260			if (d1.containsAll(c))
261			throw new Exception("d1 contains all of {Integer.MIN_VALUE }");
262			if (d2.containsAll(c))
263			throw new Exception("d2 contains all of {Integer.MIN_VALUE }");
264			}
265
266	jsr166	1.6	@SuppressWarnings("unchecked")
267			private static <T> T copyConstructorClone(T o) throws Exception {
268			return (T) o.getClass().getConstructor(Collection.class).newInstance(o);
269			}
270
271			@SuppressWarnings("unchecked")
272			private static <T> T serialClone(T o) throws Exception {
273			ByteArrayOutputStream bos = new ByteArrayOutputStream();
274			ObjectOutputStream oos = new ObjectOutputStream(bos);
275			oos.writeObject(o);
276			oos.flush();
277			oos.close();
278			ByteArrayInputStream bin =
279			new ByteArrayInputStream(bos.toByteArray());
280			ObjectInputStream ois = new ObjectInputStream(bin);
281	dl	1.1	return (T) ois.readObject();
282			}
283
284			private static void testRemove(Deque<Integer> deque) throws Exception {
285	jsr166	1.6	Deque<Integer> copy = ((random() & 1) == 0) ?
286			copyConstructorClone(deque) :
287			serialClone(deque);
288	dl	1.1
289			int numRemoved = 0;
290			for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) {
291			if ((it.next() & 1) == 0) {
292			it.remove();
293			numRemoved++;
294			}
295			}
296
297			if (copy.size() + numRemoved != size())
298			throw new Exception((copy.size() + numRemoved) + " != " + size());
299			for (int i : copy)
300			if ((i & 1) == 0)
301			throw new Exception("Even number still present: " + i);
302
303			List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0]));
304			Collections.shuffle(elements);
305			for (int e : elements) {
306			if (!copy.contains(e))
307			throw new Exception(e + " missing.");
308
309			boolean removed = false;
310	jsr166	1.5	switch (random(3)) {
311	dl	1.1	case 0: removed = copy.remove(e); break;
312			case 1: removed = copy.removeFirstOccurrence(e); break;
313			case 2: removed = copy.removeLastOccurrence(e); break;
314	jsr166	1.3	default: throw new Exception("How'd we get here");
315	dl	1.1	}
316			if (!removed)
317			throw new Exception(e + " not removed.");
318
319			if (copy.contains(e))
320			throw new Exception(e + " present after removal.");
321			}
322
323			testEmpty(copy);
324
325	jsr166	1.6	copy = copyConstructorClone(deque);
326	dl	1.1	copy.retainAll(deque);
327			testEqual(deque, copy);
328			copy.removeAll(deque);
329			testEmpty(copy);
330			}
331
332			static boolean checkedThrows;
333
334			private static void testEmpty(Deque<Integer> deque) throws Exception {
335			if (!deque.isEmpty())
336			throw new Exception("Deque isn't empty");
337			if (deque.size() != 0)
338			throw new Exception("Deque size isn't zero");
339			if (!(deque.pollFirst() == null))
340			throw new Exception("pollFirst lies");
341			if (!(deque.poll() == null))
342			throw new Exception("poll lies");
343			if (!(deque.peekFirst() == null))
344			throw new Exception("peekFirst lies");
345			if (!(deque.peek() == null))
346			throw new Exception("peek lies");
347			if (!(deque.pollLast() == null))
348			throw new Exception("pollLast lies");
349			if (!(deque.peekLast() == null))
350			throw new Exception("peekLast lies");
351
352			if (!checkedThrows) {
353			checkedThrows = true;
354			boolean threw = false;
355			int result = 666;
356			try {
357	jsr166	1.4	result = ((random() & 1) == 0 ?
358	dl	1.1	deque.getFirst() : deque.element());
359	jsr166	1.4	} catch (NoSuchElementException e) {
360	dl	1.1	threw = true;
361			}
362			if (!threw)
363			throw new Exception("getFirst-no exception: "+result);
364			threw = false;
365			try {
366			result = deque.getLast();
367	jsr166	1.4	} catch (NoSuchElementException e) {
368	dl	1.1	threw = true;
369			}
370			if (!threw)
371			throw new Exception("getLast-no exception: "+result);
372			}
373
374			}
375			}