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

/**
 * 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 bound) {
        int x = seed;
        int t = (x % 127773) * 16807 - (x / 127773) * 2836;
        seed = (t > 0) ? t : t + 0x7fffffff;
        return (t & 0x7fffffff) % bound;
    }

    static int random() {
        int x = seed;
        int t = (x % 127773) * 16807 - (x / 127773) * 2836;
        seed = (t > 0) ? t : t + 0x7fffffff;
        return (t & 0x7fffffff);
    }

    public static void main(String args[]) throws Exception {
        Class<?> cls = Class.forName(args[0]);
        int n = 1000000;

        for (int j = 0; j < 3; ++j) {
            @SuppressWarnings("unchecked")
            Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
            nextTail =  0;
            nextHead = -1;
            long start = System.nanoTime();
            mainTest(deque, n);
            long end = System.nanoTime();
            long elapsedTimeMillis = (end - start) / (1000L * 1000L);
            System.out.printf("Time: %d ms%n", elapsedTimeMillis);
            if (deque.isEmpty()) System.out.print(" ");
        }

    }

    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:	1.8
Committed:	Thu Apr 14 23:16:10 2011 UTC (13 years, 1 month ago) by jsr166
Branch:	MAIN
CVS Tags:	release-1_7_0
Changes since 1.7:	+1 -1 lines
Log Message:	whitespace
#	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			import java.util.*;
7			import java.io.*;
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	jsr166	1.3
26			static int random(int bound) {
27	dl	1.1	int x = seed;
28			int t = (x % 127773) * 16807 - (x / 127773) * 2836;
29	jsr166	1.4	seed = (t > 0) ? t : t + 0x7fffffff;
30	dl	1.1	return (t & 0x7fffffff) % bound;
31			}
32
33	jsr166	1.3	static int random() {
34	dl	1.1	int x = seed;
35			int t = (x % 127773) * 16807 - (x / 127773) * 2836;
36	jsr166	1.4	seed = (t > 0) ? t : t + 0x7fffffff;
37	dl	1.1	return (t & 0x7fffffff);
38			}
39
40			public static void main(String args[]) throws Exception {
41	jsr166	1.6	Class<?> cls = Class.forName(args[0]);
42	dl	1.1	int n = 1000000;
43
44			for (int j = 0; j < 3; ++j) {
45	jsr166	1.6	@SuppressWarnings("unchecked")
46	dl	1.1	Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
47			nextTail = 0;
48			nextHead = -1;
49	jsr166	1.6	long start = System.nanoTime();
50	dl	1.1	mainTest(deque, n);
51	jsr166	1.6	long end = System.nanoTime();
52			long elapsedTimeMillis = (end - start) / (1000L * 1000L);
53			System.out.printf("Time: %d ms%n", elapsedTimeMillis);
54	dl	1.1	if (deque.isEmpty()) System.out.print(" ");
55			}
56
57			}
58
59			static void mainTest(Deque<Integer> deque, int n) throws Exception {
60			/*
61			* Perform a random sequence of operations, keeping contiguous
62			* sequence of integers on the deque.
63			*/
64			for (int i = 0; i < n; i++) {
65			sizeTests(deque);
66			randomOp(deque);
67
68			// Test iterator occasionally
69	dl	1.2	if ((i & 1023) == 0) {
70	dl	1.1	testIter(deque);
71	dl	1.2	testDescendingIter(deque);
72			}
73	dl	1.1
74			// Test serialization and copying
75			if ((i & 4095) == 0) {
76	jsr166	1.6	testEqual(deque, serialClone(deque));
77			testEqual(deque, copyConstructorClone(deque));
78	dl	1.1	}
79	jsr166	1.3
80	dl	1.1	// Test fancy removal stuff once in a blue moon
81			if ((i & 8191) == 0)
82			testRemove(deque);
83	jsr166	1.3
84	jsr166	1.8	}
85	dl	1.1
86			// Stupid tests for clear, toString
87			deque.clear();
88			testEmpty(deque);
89			Collection<Integer> c = Arrays.asList(1, 2, 3);
90			deque.addAll(c);
91			if (!deque.toString().equals("[1, 2, 3]"))
92			throw new Exception("Deque.toString(): " + deque.toString());
93			}
94
95	jsr166	1.3	static void testIter(Deque<Integer> deque) throws Exception {
96	dl	1.1	int next = nextHead + 1;
97			int count = 0;
98			for (int j : deque) {
99			if (j != next++)
100			throw new Exception("Element "+ j + " != " + (next-1));
101			count++;
102			}
103			if (count != size())
104			throw new Exception("Count " + count + " != " + size());
105			}
106
107	jsr166	1.3	static void testDescendingIter(Deque<Integer> deque) throws Exception {
108	dl	1.2	int next = deque.size() + nextHead;
109			int count = 0;
110			for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) {
111			int j = it.next();
112			if (j != next--)
113			throw new Exception("Element "+ j + " != " + (next-1));
114			count++;
115			}
116			if (count != size())
117			throw new Exception("Count " + count + " != " + size());
118			}
119
120	dl	1.1	static void sizeTests(Deque<Integer> deque) throws Exception {
121			if (deque.size() != size())
122			throw new Exception("Size: " + deque.size() +
123			", expecting " + size());
124			if (deque.isEmpty() != (size() == 0))
125			throw new Exception(
126			"IsEmpty " + deque.isEmpty() + ", size " + size());
127			// Check head and tail
128	jsr166	1.3	if (size() == 0)
129	dl	1.1	testEmpty(deque);
130	jsr166	1.3	else
131	dl	1.1	nonEmptyTest(deque);
132
133			}
134
135	jsr166	1.3	static void nonEmptyTest(Deque<Integer> deque) throws Exception {
136	dl	1.1	if (deque.getFirst() != nextHead + 1)
137	jsr166	1.3	throw new Exception("getFirst got: " +
138	dl	1.1	deque.getFirst() + " expecting " + (nextHead + 1));
139			if (deque.element() != nextHead + 1)
140			throw new Exception("element got: " + deque.element() +
141			" expecting " + (nextHead + 1));
142			if (deque.peekFirst() != nextHead + 1)
143			throw new Exception("peekFirst got: "+deque.peekFirst() +
144			" expecting " + (nextHead + 1));
145			if (deque.peek() != nextHead + 1)
146			throw new Exception("peek got: " + deque.peek() +
147			" expecting " + (nextHead + 1));
148	jsr166	1.3
149	dl	1.1	if (deque.peekLast() != nextTail - 1)
150			throw new Exception("peekLast got: " + deque.peekLast() +
151			" expecting " + (nextTail - 1));
152			if (deque.getLast() != nextTail - 1)
153	jsr166	1.3	throw new Exception("getLast got: " +
154	dl	1.1	deque.getLast() + " expecting " + (nextTail - 1));
155	jsr166	1.3	}
156
157	dl	1.1
158			static void randomOp(Deque<Integer> deque) throws Exception {
159	jsr166	1.3
160	dl	1.1	// Perform a random operation
161	jsr166	1.5	switch (random() & 3) {
162	dl	1.1	case 0:
163	jsr166	1.5	switch (random() & 3) {
164	dl	1.1	case 0: deque.addLast(nextTail++); break;
165			case 1: deque.offerLast(nextTail++); break;
166			case 2: deque.offer(nextTail++); break;
167			case 3: deque.add(nextTail++); break;
168			default: throw new Exception("How'd we get here");
169			}
170			break;
171			case 1:
172			if (size() == 0) {
173			int result = 666;
174			boolean threw = false;
175			try {
176	jsr166	1.5	switch (random(3)) {
177	dl	1.1	case 0: result = deque.removeFirst(); break;
178			case 1: result = deque.remove(); break;
179			case 2: result = deque.pop(); break;
180			default: throw new Exception("How'd we get here");
181			}
182	jsr166	1.4	} catch (NoSuchElementException e) {
183	dl	1.1	threw = true;
184			}
185			if (!threw)
186			throw new Exception("Remove-no exception: " + result);
187			} else { // deque nonempty
188			int result = -1;
189	jsr166	1.5	switch (random(5)) {
190	dl	1.1	case 0: result = deque.removeFirst(); break;
191			case 1: result = deque.remove(); break;
192			case 2: result = deque.pop(); break;
193			case 3: result = deque.pollFirst(); break;
194			case 4: result = deque.poll(); break;
195			default: throw new Exception("How'd we get here");
196			}
197			if (result != ++nextHead)
198			throw new Exception(
199			"Removed "+ result + " expecting "+(nextHead - 1));
200			}
201			break;
202			case 2:
203	jsr166	1.5	switch (random(3)) {
204	dl	1.1	case 0: deque.addFirst(nextHead--); break;
205			case 1: deque.offerFirst(nextHead--); break;
206			case 2: deque.push(nextHead--); break;
207			default: throw new Exception("How'd we get here");
208			}
209			break;
210			case 3:
211			if (size() == 0) {
212			int result = -1;
213			boolean threw = false;
214			try {
215			result = deque.removeLast();
216	jsr166	1.4	} catch (NoSuchElementException e) {
217	dl	1.1	threw = true;
218			}
219			if (!threw)
220			throw new Exception("Remove-no exception: " + result);
221			} else { // deque nonempty
222	jsr166	1.4	int result = ((random() & 1) == 0 ?
223	dl	1.1	deque.removeLast() : deque.pollLast());
224			if (result != --nextTail)
225			throw new Exception(
226	jsr166	1.4	"Removed "+ result + " expecting "+(nextTail + 1));
227	dl	1.1	}
228			break;
229			default:
230			throw new Exception("How'd we get here");
231			}
232			}
233
234
235			private static void testEqual(Deque<Integer> d1, Deque<Integer> d2)
236			throws Exception
237			{
238			if (d1.size() != d2.size())
239			throw new Exception("Size " + d1.size() + " != " + d2.size());
240			Iterator<Integer> it = d2.iterator();
241	jsr166	1.4	for (int i : d1) {
242	dl	1.1	int j = it.next();
243			if (j != i)
244			throw new Exception("Element " + j + " != " + i);
245			}
246
247	jsr166	1.4	for (int i : d1)
248	dl	1.1	if (!d2.contains(i))
249			throw new Exception("d2 doesn't contain " + i);
250	jsr166	1.4	for (int i : d2)
251	dl	1.1	if (!d1.contains(i))
252			throw new Exception("d2 doesn't contain " + i);
253
254			if (d1.contains(Integer.MIN_VALUE))
255			throw new Exception("d2 contains Integer.MIN_VALUE");
256			if (d2.contains(Integer.MIN_VALUE))
257			throw new Exception("d2 contains Integer.MIN_VALUE");
258			if (d1.contains(null))
259			throw new Exception("d1 contains null");
260			if (d2.contains(null))
261			throw new Exception("d2 contains null");
262
263			if (!d1.containsAll(d2))
264			throw new Exception("d1 doesn't contain all of d2");
265			if (!d2.containsAll(d1))
266			throw new Exception("d2 doesn't contain all of d1");
267			Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE);
268			if (d1.containsAll(c))
269			throw new Exception("d1 contains all of {Integer.MIN_VALUE }");
270			if (d2.containsAll(c))
271			throw new Exception("d2 contains all of {Integer.MIN_VALUE }");
272			}
273
274	jsr166	1.6	@SuppressWarnings("unchecked")
275			private static <T> T copyConstructorClone(T o) throws Exception {
276			return (T) o.getClass().getConstructor(Collection.class).newInstance(o);
277			}
278
279			@SuppressWarnings("unchecked")
280			private static <T> T serialClone(T o) throws Exception {
281			ByteArrayOutputStream bos = new ByteArrayOutputStream();
282			ObjectOutputStream oos = new ObjectOutputStream(bos);
283			oos.writeObject(o);
284			oos.flush();
285			oos.close();
286			ByteArrayInputStream bin =
287			new ByteArrayInputStream(bos.toByteArray());
288			ObjectInputStream ois = new ObjectInputStream(bin);
289	dl	1.1	return (T) ois.readObject();
290			}
291
292			private static void testRemove(Deque<Integer> deque) throws Exception {
293	jsr166	1.6	Deque<Integer> copy = ((random() & 1) == 0) ?
294			copyConstructorClone(deque) :
295			serialClone(deque);
296	dl	1.1
297			int numRemoved = 0;
298			for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) {
299			if ((it.next() & 1) == 0) {
300			it.remove();
301			numRemoved++;
302			}
303			}
304
305			if (copy.size() + numRemoved != size())
306			throw new Exception((copy.size() + numRemoved) + " != " + size());
307			for (int i : copy)
308			if ((i & 1) == 0)
309			throw new Exception("Even number still present: " + i);
310
311			List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0]));
312			Collections.shuffle(elements);
313			for (int e : elements) {
314			if (!copy.contains(e))
315			throw new Exception(e + " missing.");
316
317			boolean removed = false;
318	jsr166	1.5	switch (random(3)) {
319	dl	1.1	case 0: removed = copy.remove(e); break;
320			case 1: removed = copy.removeFirstOccurrence(e); break;
321			case 2: removed = copy.removeLastOccurrence(e); break;
322	jsr166	1.3	default: throw new Exception("How'd we get here");
323	dl	1.1	}
324			if (!removed)
325			throw new Exception(e + " not removed.");
326
327			if (copy.contains(e))
328			throw new Exception(e + " present after removal.");
329			}
330
331			testEmpty(copy);
332
333	jsr166	1.6	copy = copyConstructorClone(deque);
334	dl	1.1	copy.retainAll(deque);
335			testEqual(deque, copy);
336			copy.removeAll(deque);
337			testEmpty(copy);
338			}
339
340			static boolean checkedThrows;
341
342			private static void testEmpty(Deque<Integer> deque) throws Exception {
343			if (!deque.isEmpty())
344			throw new Exception("Deque isn't empty");
345			if (deque.size() != 0)
346			throw new Exception("Deque size isn't zero");
347			if (!(deque.pollFirst() == null))
348			throw new Exception("pollFirst lies");
349			if (!(deque.poll() == null))
350			throw new Exception("poll lies");
351			if (!(deque.peekFirst() == null))
352			throw new Exception("peekFirst lies");
353			if (!(deque.peek() == null))
354			throw new Exception("peek lies");
355			if (!(deque.pollLast() == null))
356			throw new Exception("pollLast lies");
357			if (!(deque.peekLast() == null))
358			throw new Exception("peekLast lies");
359
360			if (!checkedThrows) {
361			checkedThrows = true;
362			boolean threw = false;
363			int result = 666;
364			try {
365	jsr166	1.4	result = ((random() & 1) == 0 ?
366	dl	1.1	deque.getFirst() : deque.element());
367	jsr166	1.4	} catch (NoSuchElementException e) {
368	dl	1.1	threw = true;
369			}
370			if (!threw)
371			throw new Exception("getFirst-no exception: "+result);
372			threw = false;
373			try {
374			result = deque.getLast();
375	jsr166	1.4	} catch (NoSuchElementException e) {
376	dl	1.1	threw = true;
377			}
378			if (!threw)
379			throw new Exception("getLast-no exception: "+result);
380			}
381
382			}
383			}