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8085978: LinkedTransferQueue<T>.spliterator can report LTQ.Node object, not T

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Reviewed-by: psandoz, martin
This commit is contained in:
Doug Lea 2015-06-16 13:13:05 +02:00
parent 38a04dd009
commit 975075a8c8
2 changed files with 126 additions and 8 deletions
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20
jdk/src/java.base/share/classes/java/util/concurrent/LinkedTransferQueue.java
View File

@ -780,7 +780,9 @@ public class LinkedTransferQueue<E> extends AbstractQueue<E>
}
/**
* Version of firstOfMode used by Spliterator
* Version of firstOfMode used by Spliterator. Callers must
* recheck if the returned node's item field is null or
* self-linked before using.
*/
final Node firstDataNode() {
for (Node p = head; p != null;) {
@ -953,11 +955,12 @@ public class LinkedTransferQueue<E> extends AbstractQueue<E>
Object[] a = new Object[n];
int i = 0;
do {
if ((a[i] = p.item) != null)
Object e = p.item;
if (e != p && (a[i] = e) != null)
++i;
if (p == (p = p.next))
p = q.firstDataNode();
} while (p != null && i < n);
} while (p != null && i < n && p.isData);
if ((current = p) == null)
exhausted = true;
if (i > 0) {
@ -980,11 +983,11 @@ public class LinkedTransferQueue<E> extends AbstractQueue<E>
exhausted = true;
do {
Object e = p.item;
if (e != null && e != p)
action.accept((E)e);
if (p == (p = p.next))
p = q.firstDataNode();
if (e != null)
action.accept((E)e);
} while (p != null);
} while (p != null && p.isData);
}
}
@ -997,10 +1000,11 @@ public class LinkedTransferQueue<E> extends AbstractQueue<E>
((p = current) != null || (p = q.firstDataNode()) != null)) {
Object e;
do {
e = p.item;
if ((e = p.item) == p)
e = null;
if (p == (p = p.next))
p = q.firstDataNode();
} while (e == null && p != null);
} while (e == null && p != null && p.isData);
if ((current = p) == null)
exhausted = true;
if (e != null) {

114
jdk/test/java/util/concurrent/LinkedTransferQueue/SpliteratorTraverseAddRemoveTest.java Normal file
View File

@ -0,0 +1,114 @@
/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @run testng SpliteratorTraverseAddRemoveTest
* @bug 8085978
* @summary repeatedly traverse the queue using the spliterator while
* concurrently adding and removing an element to test that self-linked
* nodes are never erroneously reported on traversal
*/
import org.testng.Assert;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import java.util.ArrayList;
import java.util.List;
import java.util.Queue;
import java.util.Spliterator;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Consumer;
@Test
public class SpliteratorTraverseAddRemoveTest {
static Object[] of(String desc, Consumer<Queue<?>> c) {
return new Object[]{desc, c};
}
static void assertIsString(Object e) {
Assert.assertTrue(e instanceof String,
String.format("Object instanceof %s (actual: instanceof %s)",
String.class.getName(),
e.getClass().getName()));
}
@DataProvider()
public static Object[][] spliteratorTraversers() {
return new Object[][]{
of("forEachRemaining", q -> {
q.spliterator().forEachRemaining(SpliteratorTraverseAddRemoveTest::assertIsString);
}),
of("tryAdvance", q -> {
Spliterator<?> s = q.spliterator();
while (s.tryAdvance(SpliteratorTraverseAddRemoveTest::assertIsString))
;
}),
of("trySplit then forEachRemaining", q -> {
Spliterator<?> r = q.spliterator();
List<Spliterator<?>> ss = new ArrayList<>();
Spliterator<?> l;
while ((l = r.trySplit()) != null) {
ss.add(l);
}
ss.add(r);
ss.forEach(s -> s.forEachRemaining(SpliteratorTraverseAddRemoveTest::assertIsString));
}),
};
}
@Test(dataProvider = "spliteratorTraversers")
public void testQueue(String desc, Consumer<Queue<String>> c)
throws InterruptedException {
AtomicBoolean done = new AtomicBoolean(false);
Queue<String> msgs = new LinkedTransferQueue<>();
CompletableFuture<Void> traversalTask = CompletableFuture.runAsync(() -> {
while (!done.get()) {
// Traversal will fail if self-linked nodes of
// LinkedTransferQueue are erroneously reported
c.accept(msgs);
}
});
CompletableFuture<Void> addAndRemoveTask = CompletableFuture.runAsync(() -> {
while (!traversalTask.isDone()) {
msgs.add("msg");
msgs.remove("msg");
}
});
Thread.sleep(TimeUnit.SECONDS.toMillis(1));
done.set(true);
addAndRemoveTask.join();
Assert.assertTrue(traversalTask.isDone());
traversalTask.join();
}
}