1/*
2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24/*
25 * @test
26 * @bug 6324846
27 * @summary Deque implementations must behave isomorphically
28 * @author Martin Buchholz
29 */
30
31import java.util.ArrayDeque;
32import java.util.Collection;
33import java.util.Deque;
34import java.util.Iterator;
35import java.util.LinkedList;
36import java.util.NoSuchElementException;
37import java.util.concurrent.ConcurrentLinkedDeque;
38import java.util.concurrent.LinkedBlockingDeque;
39
40public class ChorusLine {
41    private interface Tweaker {
42        void run(Deque<Integer> deq);
43    }
44
45    private static final Tweaker[] tweakers = {
46        new Tweaker() { public void run(Deque<Integer> deq) {
47            for (int i = 0; i < 7; i++)
48                deq.addLast(i);
49            deq.removeFirst();
50            deq.removeFirst();
51            deq.addLast(7);
52            deq.addLast(8);
53            Iterator<Integer> it = deq.descendingIterator();
54            equal(it.next(), 8);
55            it.remove();
56
57            try {it.remove();}
58            catch (IllegalStateException e) {pass();}
59            catch (Throwable t) {unexpected(t);}
60
61            deq.addLast(9);
62            it = deq.descendingIterator();
63            equal(it.next(), 9);
64            equal(it.next(), 7);
65            it.remove();
66
67            try {it.remove();}
68            catch (IllegalStateException e) {pass();}
69            catch (Throwable t) {unexpected(t);}
70
71            equal(it.next(), 6);
72
73            System.out.println(deq);
74        }},
75        new Tweaker() { public void run(Deque<Integer> deq) {
76            deq.clear();
77            check(deq.isEmpty());
78            check(deq.size() == 0);
79            check(! deq.iterator().hasNext());
80            check(! deq.descendingIterator().hasNext());
81
82            try {deq.iterator().next(); fail();}
83            catch (NoSuchElementException e) {pass();}
84            catch (Throwable t) {unexpected(t);}
85
86            try {deq.descendingIterator().next(); fail();}
87            catch (NoSuchElementException e) {pass();}
88            catch (Throwable t) {unexpected(t);}
89        }},
90        new Tweaker() { public void run(Deque<Integer> deq) {
91            for (int i = 0; i < 11; i++)
92                deq.add(i);
93            Iterator<Integer> it = deq.iterator();
94            equal(it.next(), 0);
95            equal(it.next(), 1);
96            it.remove();
97            deq.addFirst(-1);
98            deq.addFirst(-2);
99            it = deq.iterator();
100            equal(it.next(), -2);
101            equal(it.next(), -1);
102            equal(it.next(), 0);
103            it.remove();
104
105            it = deq.descendingIterator();
106
107            try {it.remove(); fail();}
108            catch (IllegalStateException e) {pass();}
109            catch (Throwable t) {unexpected(t);}
110
111            equal(it.next(), 10);
112            it.remove();
113
114            try {it.remove(); fail();}
115            catch (IllegalStateException e) {pass();}
116            catch (Throwable t) {unexpected(t);}
117
118            equal(it.next(), 9);
119            equal(it.next(), 8);
120            it.remove();
121            System.out.println(deq);
122        }},
123        new Tweaker() { public void run(Deque<Integer> deq) {
124            while (deq.size() > 1) {
125                Iterator<Integer> it = deq.iterator();
126                it.next(); it.remove();
127                it = deq.descendingIterator();
128                it.next(); it.remove();
129            }
130            System.out.println(deq);
131        }}};
132
133    private static void realMain(String[] args) throws Throwable {
134        Collection<Deque<Integer>> deqs = new ArrayDeque<>(3);
135        deqs.add(new ArrayDeque<Integer>());
136        deqs.add(new LinkedList<Integer>());
137        deqs.add(new LinkedBlockingDeque<Integer>());
138        deqs.add(new ConcurrentLinkedDeque<Integer>());
139
140        equal(deqs);
141
142        for (Tweaker tweaker : tweakers) {
143            for (Deque<Integer> deq : deqs)
144                tweaker.run(deq);
145            equal(deqs);
146        }
147    }
148
149    private static void equal(Iterable<Deque<Integer>> deqs) {
150        Deque<Integer> prev = null;
151        for (Deque<Integer> deq : deqs) {
152            if (prev != null) {
153                equal(prev.isEmpty(), deq.isEmpty());
154                equal(prev.size(), deq.size());
155                equal(prev.toString(), deq.toString());
156            }
157            prev = deq;
158        }
159
160        Deque<Iterator<Integer>> its = new ArrayDeque<>();
161        for (Deque<Integer> deq : deqs)
162            its.addLast(deq.iterator());
163        equal(its);
164
165        Deque<Iterator<Integer>> dits = new ArrayDeque<>();
166        for (Deque<Integer> deq : deqs)
167            dits.addLast(deq.descendingIterator());
168        equal(dits);
169    }
170
171    private static void equal(Deque<Iterator<Integer>> its) {
172        Iterator<Integer> it0 = its.remove();
173        while (it0.hasNext()) {
174            Integer i = it0.next();
175            for (Iterator<Integer> it : its)
176                equal(it.next(), i);
177        }
178        for (Iterator<Integer> it : its) {
179            check(! it.hasNext());
180
181            try {it.next(); fail();}
182            catch (NoSuchElementException e) {pass();}
183            catch (Throwable t) {unexpected(t);}
184        }
185    }
186
187    //--------------------- Infrastructure ---------------------------
188    static volatile int passed = 0, failed = 0;
189    static void pass() {passed++;}
190    static void fail() {failed++; Thread.dumpStack();}
191    static void fail(String msg) {System.out.println(msg); fail();}
192    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
193    static void check(boolean cond) {if (cond) pass(); else fail();}
194    static void equal(Object x, Object y) {
195        if (x == null ? y == null : x.equals(y)) pass();
196        else fail(x + " not equal to " + y);}
197    public static void main(String[] args) throws Throwable {
198        try {realMain(args);} catch (Throwable t) {unexpected(t);}
199        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
200        if (failed > 0) throw new AssertionError("Some tests failed");}
201}
202