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/**

 * @test

 * @bug 7042126

 * @summary Verify that we do not leak contents when we clone a HashMap

 * @author david.buck@oracle.com

 * @run main/othervm HashMapCloneLeak

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+EliminateAutoBox -XX:AutoBoxCacheMax=20000 HashMapCloneLeak

 */

import java.util.HashMap;

import java.lang.ref.WeakReference;

public class HashMapCloneLeak {

    static WeakReference<Object> wr = null;

    // helper method to keep testObject and map out of main method's scope

    private static HashMap<Integer, Object> makeMap() {

        HashMap<Integer, Object> map = new HashMap<Integer, Object>();

        Object testObject = new Object();

        wr = new WeakReference<Object>(testObject);

        map.put(42, testObject);

        return map;

    }

    public static void main(String[] args) throws Exception {

        HashMap<Integer, Object> hm = makeMap();

        hm = (HashMap<Integer, Object>)hm.clone();

        hm.clear();

        // There should no longer be a strong reference to testObject

        // the WeakReference should be nulled out by GC. If not,

        // we will hang here until timed out by the test harness.

        Object[] chain = null;

        while (wr.get() != null) {

            try {

                Object[] allocate = new Object[1000000];

                allocate[0] = chain;

                chain = allocate;

            } catch (OutOfMemoryError oome) {

                chain = null;

            }

            System.gc();

            Thread.sleep(100);

        }

    }

}