/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.codehaus.groovy.reflection;

import groovy.lang.GroovyClassLoader;
import org.apache.groovy.stress.util.GCUtils;
import org.codehaus.groovy.util.ReferenceBundle;

import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;

import org.codehaus.groovy.util.ReferenceManager;
import org.junit.Before;
import org.junit.Test;

import static org.junit.Assert.*;

public class ClassInfoLeakStressTest {

    private static final int NUM_OBJECTS = 3101;
    private static ReferenceBundle bundle = ReferenceBundle.getWeakBundle();

    private ReferenceQueue<ClassLoader> classLoaderQueue = new ReferenceQueue<ClassLoader>();
    private ReferenceQueue<Class<?>> classQueue = new ReferenceQueue<Class<?>>();
    private ReferenceQueue<ClassInfo> classInfoQueue = new ReferenceQueue<ClassInfo>();

    // Used to keep a hard reference to the References so they are not collected
    private List<Reference<?>> refList = new ArrayList<Reference<?>>(NUM_OBJECTS * 3);

    @Before
    public void setUp() {
        // Make sure we switch over to callback manager
        ReferenceManager manager = bundle.getManager();
        for (int i = 0; i < 1501; i++) {
            manager.afterReferenceCreation(null);
        }
    }

    @Test
    public void testLeak() {
        assertFalse(Boolean.getBoolean("groovy.use.classvalue"));
        for (int i = 0; i < NUM_OBJECTS; i++) {
            GroovyClassLoader gcl = new GroovyClassLoader();
            Class scriptClass = gcl.parseClass("int myvar = " + i);
            ClassInfo ci = ClassInfo.getClassInfo(scriptClass);
            Reference<ClassLoader> classLoaderRef = new WeakReference<ClassLoader>(gcl, classLoaderQueue);
            Reference<Class<?>> classRef = new WeakReference<Class<?>>(scriptClass, classQueue);
            Reference<ClassInfo> classInfoRef = new WeakReference<ClassInfo>(ci, classInfoQueue);
            refList.add(classLoaderRef);
            refList.add(classRef);
            refList.add(classInfoRef);
            gcl = null;
            scriptClass = null;
            ci = null;
            GCUtils.gc();
        }

        // Add new class to help evict the last collected entry
        GroovyClassLoader gcl = new GroovyClassLoader();
        Class scriptClass = gcl.parseClass("int myvar = 7777");
        ClassInfo ci = ClassInfo.getClassInfo(scriptClass);

        GCUtils.gc();

        // All objects should have been collected
        assertEquals("GroovyClassLoaders not collected by GC", NUM_OBJECTS, queueSize(classLoaderQueue));
        assertEquals("Script Classes not collected by GC", NUM_OBJECTS, queueSize(classQueue));

        int ciSize = queueSize(classInfoQueue);
        assertEquals("ClassInfo objects [" + ciSize + "] collected by GC, expected [" + NUM_OBJECTS + "]",
                NUM_OBJECTS, ciSize);
    }

    private int queueSize(ReferenceQueue<?> queue) {
        int size = 0;
        while (queue.poll() != null) {
            ++size;
        }
        return size;
    }

}