test/loops/DequeBash.java

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

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:	1.6
Committed:	Mon Sep 13 08:01:18 2010 UTC (13 years, 8 months ago) by jsr166
Branch:	MAIN
Changes since 1.5:	+27 -33 lines
Log Message:	fix javac warnings; currentTimeMillis => nanoTime
#	Content
1	/*
2	* Written by Josh Bloch of Google Inc. and released to the public domain,
3	* as explained at http://creativecommons.org/licenses/publicdomain.
4	*/
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
26	static int random(int bound) {
27	int x = seed;
28	int t = (x % 127773) * 16807 - (x / 127773) * 2836;
29	seed = (t > 0) ? t : t + 0x7fffffff;
30	return (t & 0x7fffffff) % bound;
31	}
32
33	static int random() {
34	int x = seed;
35	int t = (x % 127773) * 16807 - (x / 127773) * 2836;
36	seed = (t > 0) ? t : t + 0x7fffffff;
37	return (t & 0x7fffffff);
38	}
39
40	public static void main(String args[]) throws Exception {
41	Class<?> cls = Class.forName(args[0]);
42	int n = 1000000;
43
44	for (int j = 0; j < 3; ++j) {
45	@SuppressWarnings("unchecked")
46	Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
47	nextTail = 0;
48	nextHead = -1;
49	long start = System.nanoTime();
50	mainTest(deque, n);
51	long end = System.nanoTime();
52	long elapsedTimeMillis = (end - start) / (1000L * 1000L);
53	System.out.printf("Time: %d ms%n", elapsedTimeMillis);
54	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	if ((i & 1023) == 0) {
70	testIter(deque);
71	testDescendingIter(deque);
72	}
73
74	// Test serialization and copying
75	if ((i & 4095) == 0) {
76	testEqual(deque, serialClone(deque));
77	testEqual(deque, copyConstructorClone(deque));
78	}
79
80	// Test fancy removal stuff once in a blue moon
81	if ((i & 8191) == 0)
82	testRemove(deque);
83
84	}
85
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	static void testIter(Deque<Integer> deque) throws Exception {
96	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	static void testDescendingIter(Deque<Integer> deque) throws Exception {
108	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	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	if (size() == 0)
129	testEmpty(deque);
130	else
131	nonEmptyTest(deque);
132
133	}
134
135	static void nonEmptyTest(Deque<Integer> deque) throws Exception {
136	if (deque.getFirst() != nextHead + 1)
137	throw new Exception("getFirst got: " +
138	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
149	if (deque.peekLast() != nextTail - 1)
150	throw new Exception("peekLast got: " + deque.peekLast() +
151	" expecting " + (nextTail - 1));
152	if (deque.getLast() != nextTail - 1)
153	throw new Exception("getLast got: " +
154	deque.getLast() + " expecting " + (nextTail - 1));
155	}
156
157
158	static void randomOp(Deque<Integer> deque) throws Exception {
159
160	// Perform a random operation
161	switch (random() & 3) {
162	case 0:
163	switch (random() & 3) {
164	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	switch (random(3)) {
177	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	} catch (NoSuchElementException e) {
183	threw = true;
184	}
185	if (!threw)
186	throw new Exception("Remove-no exception: " + result);
187	} else { // deque nonempty
188	int result = -1;
189	switch (random(5)) {
190	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	switch (random(3)) {
204	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	} catch (NoSuchElementException e) {
217	threw = true;
218	}
219	if (!threw)
220	throw new Exception("Remove-no exception: " + result);
221	} else { // deque nonempty
222	int result = ((random() & 1) == 0 ?
223	deque.removeLast() : deque.pollLast());
224	if (result != --nextTail)
225	throw new Exception(
226	"Removed "+ result + " expecting "+(nextTail + 1));
227	}
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	for (int i : d1) {
242	int j = it.next();
243	if (j != i)
244	throw new Exception("Element " + j + " != " + i);
245	}
246
247	for (int i : d1)
248	if (!d2.contains(i))
249	throw new Exception("d2 doesn't contain " + i);
250	for (int i : d2)
251	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	@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	return (T) ois.readObject();
290	}
291
292	private static void testRemove(Deque<Integer> deque) throws Exception {
293	Deque<Integer> copy = ((random() & 1) == 0) ?
294	copyConstructorClone(deque) :
295	serialClone(deque);
296
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	switch (random(3)) {
319	case 0: removed = copy.remove(e); break;
320	case 1: removed = copy.removeFirstOccurrence(e); break;
321	case 2: removed = copy.removeLastOccurrence(e); break;
322	default: throw new Exception("How'd we get here");
323	}
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	copy = copyConstructorClone(deque);
334	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	result = ((random() & 1) == 0 ?
366	deque.getFirst() : deque.element());
367	} catch (NoSuchElementException e) {
368	threw = true;
369	}
370	if (!threw)
371	throw new Exception("getFirst-no exception: "+result);
372	threw = false;
373	try {
374	result = deque.getLast();
375	} catch (NoSuchElementException e) {
376	threw = true;
377	}
378	if (!threw)
379	throw new Exception("getLast-no exception: "+result);
380	}
381
382	}
383	}