concurrent/ConcurrentHashMap/ToArray.java

/*
 * Copyright (c) 2004, 2013, 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
 * @bug 4486658 8010293
 * @summary thread safety of toArray methods of collection views
 * @author Martin Buchholz
 */

import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ThreadLocalRandom;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class ToArray {

    public static void main(String[] args) throws Throwable {
        final int runsPerTest = Integer.getInteger("jsr166.runsPerTest", 1);
        final int reps = 10 * runsPerTest;
        for (int i = reps; i--> 0; )
            executeTest();
    }

    static void executeTest() throws Throwable {
        final ConcurrentHashMap<Integer, Integer> m = new ConcurrentHashMap<>();
        final ThreadLocalRandom rnd = ThreadLocalRandom.current();
        final int nCPU = Runtime.getRuntime().availableProcessors();
        final int minWorkers = 2;
        final int maxWorkers = Math.max(minWorkers, Math.min(32, nCPU));
        final int nWorkers = rnd.nextInt(minWorkers, maxWorkers + 1);
        final int sizePerWorker = 1024;
        final int maxSize = nWorkers * sizePerWorker;

        // The foreman busy-checks that the size of the arrays obtained
        // from the keys and values views grows monotonically until it
        // reaches the maximum size.

        // NOTE: these size constraints are not specific to toArray and are
        // applicable to any form of traversal of the collection views
        CompletableFuture<?> foreman = CompletableFuture.runAsync(new Runnable() {
            private int prevSize = 0;

            private boolean checkProgress(Object[] a) {
                int size = a.length;
                if (size < prevSize || size > maxSize)
                    throw new AssertionError(
                        String.format("prevSize=%d size=%d maxSize=%d",
                                      prevSize, size, maxSize));
                prevSize = size;
                return size == maxSize;
            }

            public void run() {
                Integer[] empty = new Integer[0];
                for (;;)
                    if (checkProgress(m.values().toArray())
                        & checkProgress(m.keySet().toArray())
                        & checkProgress(m.values().toArray(empty))
                        & checkProgress(m.keySet().toArray(empty)))
                        return;
            }
        });

        // Each worker puts globally unique keys into the map
        List<CompletableFuture<?>> workers =
            IntStream.range(0, nWorkers)
            .mapToObj(w -> (Runnable) () -> {
                for (int i = 0, o = w * sizePerWorker; i < sizePerWorker; i++)
                    m.put(o + i, i);
            })
            .map(CompletableFuture::runAsync)
            .collect(Collectors.toList());

        // Wait for workers and foreman to complete
        workers.forEach(CompletableFuture<?>::join);
        foreman.join();
    }
}
Revision:	1.5
Committed:	Wed Sep 4 21:37:48 2019 UTC (4 years, 9 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.4:	+2 -2 lines
Log Message:	fix imports
#	Content
1	/*
2	* Copyright (c) 2004, 2013, 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 4486658 8010293
27	* @summary thread safety of toArray methods of collection views
28	* @author Martin Buchholz
29	*/
30
31	import java.util.List;
32	import java.util.concurrent.CompletableFuture;
33	import java.util.concurrent.ConcurrentHashMap;
34	import java.util.concurrent.ThreadLocalRandom;
35	import java.util.stream.Collectors;
36	import java.util.stream.IntStream;
37
38	public class ToArray {
39
40	public static void main(String[] args) throws Throwable {
41	final int runsPerTest = Integer.getInteger("jsr166.runsPerTest", 1);
42	final int reps = 10 * runsPerTest;
43	for (int i = reps; i--> 0; )
44	executeTest();
45	}
46
47	static void executeTest() throws Throwable {
48	final ConcurrentHashMap<Integer, Integer> m = new ConcurrentHashMap<>();
49	final ThreadLocalRandom rnd = ThreadLocalRandom.current();
50	final int nCPU = Runtime.getRuntime().availableProcessors();
51	final int minWorkers = 2;
52	final int maxWorkers = Math.max(minWorkers, Math.min(32, nCPU));
53	final int nWorkers = rnd.nextInt(minWorkers, maxWorkers + 1);
54	final int sizePerWorker = 1024;
55	final int maxSize = nWorkers * sizePerWorker;
56
57	// The foreman busy-checks that the size of the arrays obtained
58	// from the keys and values views grows monotonically until it
59	// reaches the maximum size.
60
61	// NOTE: these size constraints are not specific to toArray and are
62	// applicable to any form of traversal of the collection views
63	CompletableFuture<?> foreman = CompletableFuture.runAsync(new Runnable() {
64	private int prevSize = 0;
65
66	private boolean checkProgress(Object[] a) {
67	int size = a.length;
68	if (size < prevSize \|\| size > maxSize)
69	throw new AssertionError(
70	String.format("prevSize=%d size=%d maxSize=%d",
71	prevSize, size, maxSize));
72	prevSize = size;
73	return size == maxSize;
74	}
75
76	public void run() {
77	Integer[] empty = new Integer[0];
78	for (;;)
79	if (checkProgress(m.values().toArray())
80	& checkProgress(m.keySet().toArray())
81	& checkProgress(m.values().toArray(empty))
82	& checkProgress(m.keySet().toArray(empty)))
83	return;
84	}
85	});
86
87	// Each worker puts globally unique keys into the map
88	List<CompletableFuture<?>> workers =
89	IntStream.range(0, nWorkers)
90	.mapToObj(w -> (Runnable) () -> {
91	for (int i = 0, o = w * sizePerWorker; i < sizePerWorker; i++)
92	m.put(o + i, i);
93	})
94	.map(CompletableFuture::runAsync)
95	.collect(Collectors.toList());
96
97	// Wait for workers and foreman to complete
98	workers.forEach(CompletableFuture<?>::join);
99	foreman.join();
100	}
101	}