PhantomReferenceTestCase.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jboss.modules.ref;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;

import java.lang.ref.ReferenceQueue;
import java.util.ArrayList;
import java.util.Collection;

import org.jboss.modules.ref.Reference.Type;
import org.jboss.modules.ref.util.TestReaper;
import org.junit.Test;

/**
 * Test for PhantomReference.
 *
 * @author <a href="mailto:flavia.rainone@jboss.com">Flavia Rainone</a>
 * @see PhantomReference
 */
public class PhantomReferenceTestCase extends AbstractReapableReferenceTest {

    @Test
    public void plainPhantomReference() {
        final Reference<String, String> reference = new PhantomReference<String, String>("referent", "attachment",
                (ReferenceQueue<String>) null);
        assertReference(reference, null, "attachment", null);
    }

    @Test
    public void nullPhantomReference() throws Exception {
        final Reference<Thing, Integer> reference = new PhantomReference<Thing, Integer>(null, Integer.valueOf(0), new ReferenceQueue<Thing>());
        assertReference(reference, null, Integer.valueOf(0), null);
    }

    @Test
    public void phantomReferenceWithReferenceQueue() throws Exception {
        final ReferenceQueue<Collection<Object>> referenceQueue = new ReferenceQueue<Collection<Object>>();
        Collection<Object> collection = new ArrayList<Object>();
        final Reference<Collection<Object>, String> reference = new PhantomReference<Collection<Object>, String>(collection, "collection", referenceQueue);
        assertReference(reference, null, "collection", null);
        collection = null;
        System.gc();
        assertSame(reference, referenceQueue.remove(300));
    }

    @Test
    public void phantomReferenceWithReaper() throws Exception {
        Thing thing = new Thing();
        final TestReaper<Thing, Void> reaper = new TestReaper<Thing, Void>();
        final Reference<Thing, Void> reference = new PhantomReference<Thing, Void>(thing, null, reaper);
        assertReference(reference, null, null, reaper);
        thing = null;
        System.gc();
        assertSame(reference, reaper.getReapedReference());
    }

    @Override @Test
    public void clearReference() {
        final Reference<Boolean, String> reference = createReference(Boolean.TRUE, "attachment for true");
        assertNull(reference.get());
        assertEquals("attachment for true", reference.getAttachment());

        reference.clear();
        assertNull(reference.get());
        assertEquals("attachment for true", reference.getAttachment());
    }

    @Override
    <T, A> Reference<T, A> createReference(T value, A attachment) {
        return new PhantomReference<T, A>(value, attachment, new TestReaper<T, A>());
    }

    @Override
    Type getTestedReferenceType() {
        return Type.PHANTOM;
    }
}