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 * You should have received a copy of the GNU General Public License version

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 *

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import org.testng.annotations.Test;

import java.lang.management.ManagementFactory;

import java.lang.management.ThreadInfo;

import java.lang.management.ThreadMXBean;

import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.ThreadLocalRandom;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.TimeoutException;

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/timeout=1200 ConcurrentAssociateTest

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

 * place entries in the map

 */

@Test

public class ConcurrentAssociateTest {

    /** Maximum time (in seconds) to wait for a test method to complete. */

    private static final int TIMEOUT = Integer.getInteger("timeout", 200);

    /** 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", 64);

    /** Objects to be placed in the concurrent map. */

    static class X {

        // Limit the hash code to trigger collisions

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

        public int hashCode() { return hc; }

    }

    @Test

    public void testPut() throws Throwable {

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

    }

    @Test

    public void testCompute() throws Throwable {

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

    }

    @Test

    public void testComputeIfAbsent() throws Throwable {

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

    }

    @Test

    public void testMerge() throws Throwable {

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

    }

    @Test

    public void testPutAll() throws Throwable {

        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) throws Throwable {

        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) throws Throwable {

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

        CountDownLatch s = new CountDownLatch(1);

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

            try {

                if (!s.await(TIMEOUT, TimeUnit.SECONDS)) {

                    dumpTestThreads();

                    throw new AssertionError("timed out");

                }

            }

            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");

                }

            }

        };

        // Bound concurrency to avoid degenerate performance

        int ps = Math.min(Runtime.getRuntime().availableProcessors(), 8);

        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.get(TIMEOUT, TimeUnit.SECONDS);

        } catch (TimeoutException e) {

            dumpTestThreads();

            throw e;

        } catch (Throwable e) {

            dumpTestThreads();

            Throwable cause = e.getCause();

            if (cause instanceof AssociationFailure) {

                throw cause;

            }

            throw e;

        }

    }

    /**

     * A debugging tool to print stack traces of most threads, as jstack does.

     * Uninteresting threads are filtered out.

     */

    static void dumpTestThreads() {

        ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();

        System.err.println("------ stacktrace dump start ------");

        for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {

            String name = info.getThreadName();

            if ("Signal Dispatcher".equals(name))

                continue;

            if ("Reference Handler".equals(name)

                && info.getLockName().startsWith("java.lang.ref.Reference$Lock"))

                continue;

            if ("Finalizer".equals(name)

                && info.getLockName().startsWith("java.lang.ref.ReferenceQueue$Lock"))

                continue;

            System.err.print(info);

        }

        System.err.println("------ stacktrace dump end ------");

    }

}