1/*
2 * Copyright (c) 2015, 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 * @run testng SpliteratorTraverseAddRemoveTest
27 * @bug 8085978
28 * @summary repeatedly traverse the queue using the spliterator while
29 *          concurrently adding and removing an element to test that self-linked
30 *          nodes are never erroneously reported on traversal
31 */
32
33import org.testng.Assert;
34import org.testng.annotations.DataProvider;
35import org.testng.annotations.Test;
36
37import java.util.ArrayList;
38import java.util.List;
39import java.util.Queue;
40import java.util.Spliterator;
41import java.util.concurrent.CompletableFuture;
42import java.util.concurrent.LinkedTransferQueue;
43import java.util.concurrent.TimeUnit;
44import java.util.concurrent.atomic.AtomicBoolean;
45import java.util.function.Consumer;
46
47@Test
48public class SpliteratorTraverseAddRemoveTest {
49
50    static Object[] of(String desc, Consumer<Queue<?>> c) {
51        return new Object[]{desc, c};
52    }
53
54    static void assertIsString(Object e) {
55        Assert.assertTrue(e instanceof String,
56                          String.format("Object instanceof %s (actual: instanceof %s)",
57                                        String.class.getName(),
58                                        e.getClass().getName()));
59    }
60
61    @DataProvider()
62    public static Object[][] spliteratorTraversers() {
63        return new Object[][]{
64                of("forEachRemaining", q -> {
65                    q.spliterator().forEachRemaining(SpliteratorTraverseAddRemoveTest::assertIsString);
66                }),
67                of("tryAdvance", q -> {
68                    Spliterator<?> s = q.spliterator();
69                    while (s.tryAdvance(SpliteratorTraverseAddRemoveTest::assertIsString))
70                        ;
71                }),
72                of("trySplit then forEachRemaining", q -> {
73                    Spliterator<?> r = q.spliterator();
74
75                    List<Spliterator<?>> ss = new ArrayList<>();
76                    Spliterator<?> l;
77                    while ((l = r.trySplit()) != null) {
78                        ss.add(l);
79                    }
80                    ss.add(r);
81
82                    ss.forEach(s -> s.forEachRemaining(SpliteratorTraverseAddRemoveTest::assertIsString));
83                }),
84        };
85    }
86
87    @Test(dataProvider = "spliteratorTraversers")
88    public void testQueue(String desc, Consumer<Queue<String>> c)
89            throws InterruptedException {
90        AtomicBoolean done = new AtomicBoolean(false);
91        Queue<String> msgs = new LinkedTransferQueue<>();
92
93        CompletableFuture<Void> traversalTask = CompletableFuture.runAsync(() -> {
94            while (!done.get()) {
95                // Traversal will fail if self-linked nodes of
96                // LinkedTransferQueue are erroneously reported
97                c.accept(msgs);
98            }
99        });
100        CompletableFuture<Void> addAndRemoveTask = CompletableFuture.runAsync(() -> {
101            while (!traversalTask.isDone()) {
102                msgs.add("msg");
103                msgs.remove("msg");
104            }
105        });
106
107        Thread.sleep(TimeUnit.SECONDS.toMillis(1));
108        done.set(true);
109
110        addAndRemoveTask.join();
111        Assert.assertTrue(traversalTask.isDone());
112        traversalTask.join();
113    }
114}
115