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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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.

 *

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/**

 * @test

 * @bug 8005698

 * @summary Check operation of jdk.map.useRandomSeed property

 * @run main CheckRandomHashSeed

 * @run main/othervm -Djdk.map.useRandomSeed=false CheckRandomHashSeed

 * @run main/othervm -Djdk.map.useRandomSeed=bogus CheckRandomHashSeed

 * @run main/othervm -Djdk.map.useRandomSeed=true CheckRandomHashSeed true

 * @author Brent Christian

 */

import java.lang.reflect.Field;

import java.util.Map;

import java.util.HashMap;

import java.util.LinkedHashMap;

import java.util.Hashtable;

import java.util.WeakHashMap;

public class CheckRandomHashSeed {

    private final static String PROP_NAME = "jdk.map.useRandomSeed";

    static boolean expectRandom = false;

    public static void main(String[] args) {

        if (args.length > 0 && args[0].equals("true")) {

            expectRandom = true;

        }

        String hashSeedProp = System.getProperty(PROP_NAME);

        boolean propSet = (null != hashSeedProp)

                ? Boolean.parseBoolean(hashSeedProp) : false;

        if (expectRandom != propSet) {

            throw new Error("Error in test setup: " + (expectRandom ? "" : "not " ) + "expecting random hashSeed, but " + PROP_NAME + " is " + (propSet ? "" : "not ") + "enabled");

        }

        testMap(new WeakHashMap());

        testMap(new Hashtable());

    }

    private static void testMap(Map map) {

        int hashSeed = getHashSeed(map);

        boolean hashSeedIsZero = (hashSeed == 0);

        if (expectRandom != hashSeedIsZero) {

            System.out.println("Test passed for " + map.getClass().getSimpleName() + " - expectRandom: " + expectRandom + ", hashSeed: " + hashSeed);

        } else {

            throw new Error ("Test FAILED for " + map.getClass().getSimpleName() + " -  expectRandom: " + expectRandom + ", hashSeed: " + hashSeed);

        }

    }

    private static int getHashSeed(Map map) {

        try {

            if (map instanceof HashMap || map instanceof LinkedHashMap) {

                map.put("Key", "Value");

                Field hashSeedField = HashMap.class.getDeclaredField("hashSeed");

                hashSeedField.setAccessible(true);

                int hashSeed = hashSeedField.getInt(map);

                return hashSeed;

            } else {

                map.put("Key", "Value");

                Field hashSeedField = map.getClass().getDeclaredField("hashSeed");

                hashSeedField.setAccessible(true);

                int hashSeed = hashSeedField.getInt(map);

                return hashSeed;

            }

        } catch(Exception e) {

            e.printStackTrace();

            throw new Error(e);

        }

    }

}