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) {
            Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
            nextTail =  0;
            nextHead = -1;
            long start = System.currentTimeMillis();
            mainTest(deque, n);
            long end = System.currentTimeMillis();
            System.out.println("Time: " + (end - start) + "ms");
            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, deepCopy(deque));
                testEqual(deque, (Deque<Integer>) deque.getClass().
                          getConstructor(Collection.class).newInstance(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 }");
    }

    private static <T> T deepCopy(T o) {
        try {
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(bos);
            oos.writeObject(o);
            oos.flush();
            ByteArrayInputStream bin = new ByteArrayInputStream(
                bos.toByteArray());
            ObjectInputStream ois = new ObjectInputStream(bin);
            return (T) ois.readObject();
        } catch(Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    private static void testRemove(Deque<Integer> deque) throws Exception {
        Deque<Integer> copy = null;
        switch(random() & 1) {
          case 0:
            copy = (Deque<Integer>) deque.getClass().
                getConstructor(Collection.class).newInstance(deque);
            break;
          case 1:
            copy = deepCopy(deque);
            break;
          default:
            throw new Exception("How'd we get here");
        }

        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 = (Deque<Integer>) deque.getClass().
            getConstructor(Collection.class).newInstance(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:	1.3
Committed:	Thu Oct 29 23:09:07 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.2:	+17 -17 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			* 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	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			seed = (t > 0)? t : t + 0x7fffffff;
30			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			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			Deque<Integer> deque = (Deque<Integer>) cls.newInstance();
46			nextTail = 0;
47			nextHead = -1;
48			long start = System.currentTimeMillis();
49			mainTest(deque, n);
50			long end = System.currentTimeMillis();
51			System.out.println("Time: " + (end - start) + "ms");
52			if (deque.isEmpty()) System.out.print(" ");
53			}
54
55			}
56
57			static void mainTest(Deque<Integer> deque, int n) throws Exception {
58			/*
59			* Perform a random sequence of operations, keeping contiguous
60			* sequence of integers on the deque.
61			*/
62			for (int i = 0; i < n; i++) {
63			sizeTests(deque);
64			randomOp(deque);
65
66			// Test iterator occasionally
67	dl	1.2	if ((i & 1023) == 0) {
68	dl	1.1	testIter(deque);
69	dl	1.2	testDescendingIter(deque);
70			}
71	dl	1.1
72			// Test serialization and copying
73			if ((i & 4095) == 0) {
74			testEqual(deque, deepCopy(deque));
75			testEqual(deque, (Deque<Integer>) deque.getClass().
76			getConstructor(Collection.class).newInstance(deque));
77			}
78	jsr166	1.3
79	dl	1.1	// Test fancy removal stuff once in a blue moon
80			if ((i & 8191) == 0)
81			testRemove(deque);
82	jsr166	1.3
83	dl	1.1	}
84
85			// Stupid tests for clear, toString
86			deque.clear();
87			testEmpty(deque);
88			Collection<Integer> c = Arrays.asList(1, 2, 3);
89			deque.addAll(c);
90			if (!deque.toString().equals("[1, 2, 3]"))
91			throw new Exception("Deque.toString(): " + deque.toString());
92			}
93
94	jsr166	1.3	static void testIter(Deque<Integer> deque) throws Exception {
95	dl	1.1	int next = nextHead + 1;
96			int count = 0;
97			for (int j : deque) {
98			if (j != next++)
99			throw new Exception("Element "+ j + " != " + (next-1));
100			count++;
101			}
102			if (count != size())
103			throw new Exception("Count " + count + " != " + size());
104			}
105
106	jsr166	1.3	static void testDescendingIter(Deque<Integer> deque) throws Exception {
107	dl	1.2	int next = deque.size() + nextHead;
108			int count = 0;
109			for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) {
110			int j = it.next();
111			if (j != next--)
112			throw new Exception("Element "+ j + " != " + (next-1));
113			count++;
114			}
115			if (count != size())
116			throw new Exception("Count " + count + " != " + size());
117			}
118
119	dl	1.1	static void sizeTests(Deque<Integer> deque) throws Exception {
120			if (deque.size() != size())
121			throw new Exception("Size: " + deque.size() +
122			", expecting " + size());
123			if (deque.isEmpty() != (size() == 0))
124			throw new Exception(
125			"IsEmpty " + deque.isEmpty() + ", size " + size());
126			// Check head and tail
127	jsr166	1.3	if (size() == 0)
128	dl	1.1	testEmpty(deque);
129	jsr166	1.3	else
130	dl	1.1	nonEmptyTest(deque);
131
132			}
133
134	jsr166	1.3	static void nonEmptyTest(Deque<Integer> deque) throws Exception {
135	dl	1.1	if (deque.getFirst() != nextHead + 1)
136	jsr166	1.3	throw new Exception("getFirst got: " +
137	dl	1.1	deque.getFirst() + " expecting " + (nextHead + 1));
138			if (deque.element() != nextHead + 1)
139			throw new Exception("element got: " + deque.element() +
140			" expecting " + (nextHead + 1));
141			if (deque.peekFirst() != nextHead + 1)
142			throw new Exception("peekFirst got: "+deque.peekFirst() +
143			" expecting " + (nextHead + 1));
144			if (deque.peek() != nextHead + 1)
145			throw new Exception("peek got: " + deque.peek() +
146			" expecting " + (nextHead + 1));
147	jsr166	1.3
148	dl	1.1	if (deque.peekLast() != nextTail - 1)
149			throw new Exception("peekLast got: " + deque.peekLast() +
150			" expecting " + (nextTail - 1));
151			if (deque.getLast() != nextTail - 1)
152	jsr166	1.3	throw new Exception("getLast got: " +
153	dl	1.1	deque.getLast() + " expecting " + (nextTail - 1));
154	jsr166	1.3	}
155
156	dl	1.1
157			static void randomOp(Deque<Integer> deque) throws Exception {
158	jsr166	1.3
159	dl	1.1	// Perform a random operation
160			switch(random() & 3) {
161			case 0:
162			switch(random() & 3) {
163			case 0: deque.addLast(nextTail++); break;
164			case 1: deque.offerLast(nextTail++); break;
165			case 2: deque.offer(nextTail++); break;
166			case 3: deque.add(nextTail++); break;
167			default: throw new Exception("How'd we get here");
168			}
169			break;
170			case 1:
171			if (size() == 0) {
172			int result = 666;
173			boolean threw = false;
174			try {
175			switch(random(3)) {
176			case 0: result = deque.removeFirst(); break;
177			case 1: result = deque.remove(); break;
178			case 2: result = deque.pop(); break;
179			default: throw new Exception("How'd we get here");
180			}
181			} catch(NoSuchElementException e) {
182			threw = true;
183			}
184			if (!threw)
185			throw new Exception("Remove-no exception: " + result);
186			} else { // deque nonempty
187			int result = -1;
188			switch(random(5)) {
189			case 0: result = deque.removeFirst(); break;
190			case 1: result = deque.remove(); break;
191			case 2: result = deque.pop(); break;
192			case 3: result = deque.pollFirst(); break;
193			case 4: result = deque.poll(); break;
194			default: throw new Exception("How'd we get here");
195			}
196			if (result != ++nextHead)
197			throw new Exception(
198			"Removed "+ result + " expecting "+(nextHead - 1));
199			}
200			break;
201			case 2:
202			switch(random(3)) {
203			case 0: deque.addFirst(nextHead--); break;
204			case 1: deque.offerFirst(nextHead--); break;
205			case 2: deque.push(nextHead--); break;
206			default: throw new Exception("How'd we get here");
207			}
208			break;
209			case 3:
210			if (size() == 0) {
211			int result = -1;
212			boolean threw = false;
213			try {
214			result = deque.removeLast();
215			} catch(NoSuchElementException e) {
216			threw = true;
217			}
218			if (!threw)
219			throw new Exception("Remove-no exception: " + result);
220			} else { // deque nonempty
221			int result = ((random() & 1) == 0?
222			deque.removeLast() : deque.pollLast());
223			if (result != --nextTail)
224			throw new Exception(
225			"Removed "+ result + " expecting "+(nextTail + 1));
226			}
227			break;
228			default:
229			throw new Exception("How'd we get here");
230			}
231			}
232
233
234			private static void testEqual(Deque<Integer> d1, Deque<Integer> d2)
235			throws Exception
236			{
237			if (d1.size() != d2.size())
238			throw new Exception("Size " + d1.size() + " != " + d2.size());
239			Iterator<Integer> it = d2.iterator();
240			for(int i : d1) {
241			int j = it.next();
242			if (j != i)
243			throw new Exception("Element " + j + " != " + i);
244			}
245
246			for(int i : d1)
247			if (!d2.contains(i))
248			throw new Exception("d2 doesn't contain " + i);
249			for(int i : d2)
250			if (!d1.contains(i))
251			throw new Exception("d2 doesn't contain " + i);
252
253			if (d1.contains(Integer.MIN_VALUE))
254			throw new Exception("d2 contains Integer.MIN_VALUE");
255			if (d2.contains(Integer.MIN_VALUE))
256			throw new Exception("d2 contains Integer.MIN_VALUE");
257			if (d1.contains(null))
258			throw new Exception("d1 contains null");
259			if (d2.contains(null))
260			throw new Exception("d2 contains null");
261
262			if (!d1.containsAll(d2))
263			throw new Exception("d1 doesn't contain all of d2");
264			if (!d2.containsAll(d1))
265			throw new Exception("d2 doesn't contain all of d1");
266			Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE);
267			if (d1.containsAll(c))
268			throw new Exception("d1 contains all of {Integer.MIN_VALUE }");
269			if (d2.containsAll(c))
270			throw new Exception("d2 contains all of {Integer.MIN_VALUE }");
271			}
272
273			private static <T> T deepCopy(T o) {
274			try {
275			ByteArrayOutputStream bos = new ByteArrayOutputStream();
276			ObjectOutputStream oos = new ObjectOutputStream(bos);
277			oos.writeObject(o);
278			oos.flush();
279			ByteArrayInputStream bin = new ByteArrayInputStream(
280			bos.toByteArray());
281			ObjectInputStream ois = new ObjectInputStream(bin);
282			return (T) ois.readObject();
283			} catch(Exception e) {
284			throw new IllegalArgumentException(e);
285			}
286			}
287
288			private static void testRemove(Deque<Integer> deque) throws Exception {
289			Deque<Integer> copy = null;
290			switch(random() & 1) {
291			case 0:
292			copy = (Deque<Integer>) deque.getClass().
293			getConstructor(Collection.class).newInstance(deque);
294			break;
295			case 1:
296			copy = deepCopy(deque);
297			break;
298			default:
299			throw new Exception("How'd we get here");
300			}
301
302			int numRemoved = 0;
303			for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) {
304			if ((it.next() & 1) == 0) {
305			it.remove();
306			numRemoved++;
307			}
308			}
309
310			if (copy.size() + numRemoved != size())
311			throw new Exception((copy.size() + numRemoved) + " != " + size());
312			for (int i : copy)
313			if ((i & 1) == 0)
314			throw new Exception("Even number still present: " + i);
315
316			List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0]));
317			Collections.shuffle(elements);
318			for (int e : elements) {
319			if (!copy.contains(e))
320			throw new Exception(e + " missing.");
321
322			boolean removed = false;
323			switch(random(3)) {
324			case 0: removed = copy.remove(e); break;
325			case 1: removed = copy.removeFirstOccurrence(e); break;
326			case 2: removed = copy.removeLastOccurrence(e); break;
327	jsr166	1.3	default: throw new Exception("How'd we get here");
328	dl	1.1	}
329			if (!removed)
330			throw new Exception(e + " not removed.");
331
332			if (copy.contains(e))
333			throw new Exception(e + " present after removal.");
334			}
335
336			testEmpty(copy);
337
338			copy = (Deque<Integer>) deque.getClass().
339			getConstructor(Collection.class).newInstance(deque);
340			copy.retainAll(deque);
341			testEqual(deque, copy);
342			copy.removeAll(deque);
343			testEmpty(copy);
344			}
345
346			static boolean checkedThrows;
347
348			private static void testEmpty(Deque<Integer> deque) throws Exception {
349			if (!deque.isEmpty())
350			throw new Exception("Deque isn't empty");
351			if (deque.size() != 0)
352			throw new Exception("Deque size isn't zero");
353			if (!(deque.pollFirst() == null))
354			throw new Exception("pollFirst lies");
355			if (!(deque.poll() == null))
356			throw new Exception("poll lies");
357			if (!(deque.peekFirst() == null))
358			throw new Exception("peekFirst lies");
359			if (!(deque.peek() == null))
360			throw new Exception("peek lies");
361			if (!(deque.pollLast() == null))
362			throw new Exception("pollLast lies");
363			if (!(deque.peekLast() == null))
364			throw new Exception("peekLast lies");
365
366			if (!checkedThrows) {
367			checkedThrows = true;
368			boolean threw = false;
369			int result = 666;
370			try {
371			result = ((random() & 1) == 0?
372			deque.getFirst() : deque.element());
373			} catch(NoSuchElementException e) {
374			threw = true;
375			}
376			if (!threw)
377			throw new Exception("getFirst-no exception: "+result);
378			threw = false;
379			try {
380			result = deque.getLast();
381			} catch(NoSuchElementException e) {
382			threw = true;
383			}
384			if (!threw)
385			throw new Exception("getLast-no exception: "+result);
386			}
387
388			}
389			}