/*

 * Copyright (c) 2003, 2004, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @bug     4858522

 * @summary Basic unit test of UnixOperatingSystemMXBean.getOpenFileDescriptorCount()

 * @author  Steve Bohne

 */

/*

 * This test is just a sanity check and does not check for the correct

 * value.  The correct value should be checked manually:

 * Solaris/Linux:

 *   1. Find the pid of the java process.

 *   2. In a shell, enter the command: "ls -1 /proc/<pid>/fd | wc -l"

 */

import com.sun.management.UnixOperatingSystemMXBean;

import java.lang.management.*;

public class GetOpenFileDescriptorCount {

    private static UnixOperatingSystemMXBean mbean =

        (UnixOperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();

    // Careful with these values.

    private static final long MIN_COUNT_FOR_PASS = 1;

    // Max count for pass dynamically determined below

    private static long       max_count_for_pass = Long.MAX_VALUE;

    private static boolean trace = false;

    public static void main(String args[]) throws Exception {

        if (args.length > 0 && args[0].equals("trace")) {

            trace = true;

        }

        long max_count = mbean.getMaxFileDescriptorCount();

        if (max_count > 0) {

            max_count_for_pass = max_count;

        }

        long count = mbean.getOpenFileDescriptorCount();

        if (trace) {

            System.out.println("Open file descriptor count: " + count);

        }

        if (count < MIN_COUNT_FOR_PASS || count > max_count_for_pass) {

            throw new RuntimeException("Open file descriptor count " +

                                       "illegal value: " + count + " bytes " +

                                       "(MIN = " + MIN_COUNT_FOR_PASS + "; " +

                                       "MAX = " + max_count_for_pass + ")");

        }

        System.out.println("Test passed.");

    }

}