LastElement.java

/*
 * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * 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.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

/*
 * @test
 * @bug 6215625
 * @summary Check correct behavior when last element is removed.
 * @author Martin Buchholz
 */

import java.util.*;
import java.util.concurrent.*;

public class LastElement {
    static volatile int passed = 0, failed = 0;

    static void fail(String msg) {
        failed++;
        new Exception(msg).printStackTrace();
    }

    static void pass() {
        passed++;
    }

    static void unexpected(Throwable t) {
        failed++;
        t.printStackTrace();
    }

    static void check(boolean condition, String msg) {
        if (condition)
            passed++;
        else
            fail(msg);
    }

    static void check(boolean condition) {
        check(condition, "Assertion failure");
    }

    public static void main(String[] args) throws Throwable {
        testQueue(new LinkedBlockingQueue<Integer>());
        // Uncomment when LinkedBlockingDeque is integrated
        //testQueue(new LinkedBlockingDeque<Integer>());
        testQueue(new ArrayBlockingQueue<Integer>(10));

        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
        if (failed > 0) throw new Exception("Some tests failed");
    }

    private static void testQueue(BlockingQueue<Integer> q) throws Throwable {
        Integer one = 1;
        Integer two = 2;
        Integer three = 3;

        // remove(Object)
        q.put(one);
        q.put(two);
        check(! q.isEmpty() && q.size() == 2);
        check(q.remove(one));
        check(q.remove(two));
        check(q.isEmpty() && q.size() == 0);
        q.put(three);
        try {check(q.take() == three);}
        catch (Throwable t) {unexpected(t);}
        check(q.isEmpty() && q.size() == 0);

        // iterator().remove()
        q.clear();
        q.put(one);
        check(q.offer(two));
        check(! q.isEmpty() && q.size() == 2);
        Iterator<Integer> i = q.iterator();
        check(i.next() == one);
        i.remove();
        check(i.next() == two);
        i.remove();
        check(q.isEmpty() && q.size() == 0);
        q.put(three);
        try {check(q.take() == three);}
        catch (Throwable t) {unexpected(t);}
        check(q.isEmpty() && q.size() == 0);
    }
}