executelockscdcscript.java.svn-base

来自「cqME :java framework for TCK test.」· SVN-BASE 代码 · 共 123 行

/*
 * $Id$
 *
 * Copyright 1996-2007 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * This program 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 program 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 at /legal/license.txt).
 *
 * 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 or visit www.sun.com if you need additional
 * information or have any questions.
 *
 */

package com.sun.tck.j2me.javatest;

import com.sun.javatest.ResourceTable;
import com.sun.javatest.Status;
import com.sun.javatest.TestDescription;
import com.sun.javatest.TestEnvironment;
import com.sun.javatest.util.StringArray;
import com.sun.tck.javatest.TCKScript;

/**
 * An extension to the {@link TCKScript base TCK Script} for CDC,
 * provides "executeLocks" functionality. Allows to use simple named
 * locks to serialize access to arbitrary resources that require
 * exclusive use.
 * <p>
 * For example, some tests might adjust security environment for their
 * testing needs via <code>SecurityManager</code>, and running such
 * security-sensitive tests concurrently would lead to interference
 * between tests, which is not desired. Marking such tests with a
 * named lock, e.g., "SecurityManager" would allow to run the tests
 * one by one to avoid interference.
 * <p>
 * <b>Note:</b> This Script should not be used in cases when test
 * bundling is involved, e.g., in CLDC/MIDP cases.
 */
public class ExecuteLocksCdcScript extends TCKScript {

    /**
     * The name of <code>TestDescription</code>'s parameter to get
     * the lock names. The lock names should be separated by spaces.
     */
    public static final String EXECUTE_LOCKS_PARAMETER = "executeLocks";

    /**
     * Creates a Script instance.
     */
    public ExecuteLocksCdcScript() {
    }

    public Status run(String[] args, TestDescription td, TestEnvironment env) {
        String[] locks = StringArray.split(
                td.getParameter(EXECUTE_LOCKS_PARAMETER));
        try {
            boolean ok = lockExecution(locks);
            if (!ok) {
                return Status.error("Timeout waiting to acquire internal "
                        + "locks on: " + StringArray.join(locks));
            }
            return super.run(args, td, env);
        } catch (InterruptedException e) {
            return Status.error(
                    "timeout waiting to acquire internal locks on: "
                    + StringArray.join(locks));
        } finally {
            unlockExecution(locks);
        }
    }

    /**
     * Tries to acquire a set of named locks. To avoid deadlocks, the
     * locks are acquired in a canonical order (alphabetical by name).
     *
     * @param locks
     *                A list of names identifying locks to be
     *                acquired.
     * @return <code>true</code> if and only if all the locks were
     *         successfully acquired
     * @throws InterruptedException
     *                 if the method was interrupted while waiting for
     *                 the locks to become available.
     */
    protected boolean lockExecution(String[] locks)
            throws InterruptedException {
        if (locks.length == 0) {
            return true;
        }
        return lockTable.acquire(locks, Integer.MAX_VALUE);
    }

    /**
     * Releases a set of previously acquired locks. The named locks are
     * only released if currently owned by the same thread that
     * acquired them.
     *
     * @param locks
     *                The names of the locks to be released.
     */
    protected void unlockExecution(String[] locks) {
        if (locks.length > 0) {
            lockTable.release(locks);
        }
    }

    private static ResourceTable lockTable = new ResourceTable();
}