/*

 * Copyright (c) 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

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 * questions.

 */

import org.testng.annotations.Test;

import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.CompletionException;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.ThreadLocalRandom;

import java.util.function.BiConsumer;

import java.util.function.Supplier;

import java.util.stream.IntStream;

import java.util.stream.Stream;

/**

 * @test

 * @bug 8028564

 * @run testng ConcurrentAssociateTest

 * @summary Test that association operations, such as put and compute,

 * place entries in the map

 */

@Test

public class ConcurrentAssociateTest {

    // The number of entries for each thread to place in a map

    private static final int N = Integer.getInteger("n", 128);

    // The number of iterations of the test

    private static final int I = Integer.getInteger("i", 256);

    // Object to be placed in the concurrent map

    static class X {

        // Limit the hash code to trigger collisions

        int hc = ThreadLocalRandom.current().nextInt(1, 9);

        public int hashCode() { return hc; }

    }

    @Test

    public void testPut() {

        test("CHM.put", (m, o) -> m.put(o, o));

    }

    @Test

    public void testCompute() {

        test("CHM.compute", (m, o) -> m.compute(o, (k, v) -> o));

    }

    @Test

    public void testComputeIfAbsent() {

        test("CHM.computeIfAbsent", (m, o) -> m.computeIfAbsent(o, (k) -> o));

    }

    @Test

    public void testMerge() {

        test("CHM.merge", (m, o) -> m.merge(o, o, (v1, v2) -> v1));

    }

    @Test

    public void testPutAll() {

        test("CHM.putAll", (m, o) -> {

            Map<Object, Object> hm = new HashMap<>();

            hm.put(o, o);

            m.putAll(hm);

        });

    }

    private static void test(String desc, BiConsumer<ConcurrentMap<Object, Object>, Object> associator) {

        for (int i = 0; i < I; i++) {

            testOnce(desc, associator);

        }

    }

    static class AssociationFailure extends RuntimeException {

        AssociationFailure(String message) {

            super(message);

        }

    }

    private static void testOnce(String desc, BiConsumer<ConcurrentMap<Object, Object>, Object> associator) {

        ConcurrentHashMap<Object, Object> m = new ConcurrentHashMap<>();

        CountDownLatch s = new CountDownLatch(1);

        Supplier<Runnable> sr = () -> () -> {

            try {

                s.await();

            }

            catch (InterruptedException e) {

            }

            for (int i = 0; i < N; i++) {

                Object o = new X();

                associator.accept(m, o);

                if (!m.containsKey(o)) {

                    throw new AssociationFailure(desc + " failed: entry does not exist");

                }

            }

        };

        int ps = Runtime.getRuntime().availableProcessors();

        Stream<CompletableFuture> runners = IntStream.range(0, ps)

                .mapToObj(i -> sr.get())

                .map(CompletableFuture::runAsync);

        CompletableFuture all = CompletableFuture.allOf(

                runners.toArray(CompletableFuture[]::new));

        // Trigger the runners to start associating

        s.countDown();

        try {

            all.join();

        } catch (CompletionException e) {

            Throwable t = e.getCause();

            if (t instanceof AssociationFailure) {

                throw (AssociationFailure) t;

            }

            else {

                throw e;

            }

        }

    }

}