/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * 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.wamblee.concurrency;

import junit.framework.TestCase;

import org.wamblee.test.EventTracker;
import org.wamblee.test.TimingUtils;

/**
 * Tests for the JVMLock.
 * 
 * @author Erik Brakkee
 */
public abstract class AbstractLockTestCase extends TestCase {
    protected static final int SLEEP_TIME = 1000;
    protected static final String STARTED = "started";
    protected static final String ACQUIRED = "acquired";
    protected static final String RELEASED = "released";
    private EventTracker<String> tracker;

    /*
     * (non-Javadoc)
     * 
     * @see junit.framework.TestCase#setUp()
     */
    @Override
    protected void setUp() throws Exception {
        tracker = new EventTracker<String>();
    }

    protected EventTracker<String> getTracker() {
        return tracker;
    }

    /**
     * Must be implemented to generate the events {@link #STARTED},
     * {@link #ACQUIRED}, and {@link #RELEASED} in that order. The lock should
     * be acquired for the time specified by {@link #SLEEP_TIME}.
     * 
     * @return Thread which does the work.
     */
    protected abstract Thread runThread();

    /**
     * Tests the operation of the lock.
     */
    public void testLock() throws InterruptedException {
        Thread t1 = runThread();
        Thread t2 = runThread();
        TimingUtils.sleep(SLEEP_TIME / 2); // give threads a chance to start
        // up.

        assertEquals(2, tracker.getEventCount(STARTED)); // both threads
        // should have
        // started.

        assertEquals(1, tracker.getEventCount(ACQUIRED)); // one thread has
        // acquired the
        // lock.

        TimingUtils.sleep(SLEEP_TIME);
        assertEquals(2, tracker.getEventCount(ACQUIRED)); // now the other
        // thread could also
        // acquire the lock

        assertEquals(1, tracker.getEventCount(RELEASED)); // and the first
        // thread has
        // released it.

        TimingUtils.sleep(SLEEP_TIME);
        assertEquals(2, tracker.getEventCount(RELEASED)); // both threads
        // should be
        // finished.

        t1.join();
        t2.join();
    }
}