1 /*

     2  * Copyright 2003-2004 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug     4530538

    27  * @summary Basic Test for HotspotThreadMBean.getInternalThreadCount()

    28  *          and getInternalThreadCpuTime()

    29  * @author  Mandy Chung

    30  */

    31 

    32 import sun.management.*;

    33 import java.util.*;

    34 import java.lang.management.ThreadMXBean;

    35 

    36 public class GetInternalThreads {

    37     private static HotspotThreadMBean mbean =

    38         ManagementFactory.getHotspotThreadMBean();

    39 

    40     // Minimum number of VM internal threads

    41     //   VM thread, watcher thread, Low memory detector, compiler thread

    42     private static final long MIN_VALUE_FOR_PASS = 4;

    43     private static final long MAX_VALUE_FOR_PASS = Long.MAX_VALUE;

    44 

    45     public static void main(String[] args) {

    46         long value = mbean.getInternalThreadCount();

    47 

    48         if (value < MIN_VALUE_FOR_PASS || value > MAX_VALUE_FOR_PASS) {

    49             throw new RuntimeException("Internal thread count " +

    50                                        "illegal value: " + value + " " +

    51                                        "(MIN = " + MIN_VALUE_FOR_PASS + "; " +

    52                                        "MAX = " + MAX_VALUE_FOR_PASS + ")");

    53         }

    54 

    55         System.out.println("Internal Thread Count = " + value);

    56 

    57         ThreadMXBean thread =

    58             java.lang.management.ManagementFactory.getThreadMXBean();

    59         if (!thread.isThreadCpuTimeSupported()) {

    60             System.out.println("Thread Cpu Time is not supported.");

    61             return;

    62         }

    63 

    64         Map times = mbean.getInternalThreadCpuTimes();

    65         Iterator iter = times.entrySet().iterator();

    66         for (; iter.hasNext(); ) {

    67             Map.Entry entry = (Map.Entry) iter.next();

    68             System.out.println(entry.getKey() +

    69                 " CPU time = " + entry.getValue() + "ns");

    70             if (((Long) entry.getValue()).longValue() < 0) {

    71                 throw new RuntimeException("Thread CPU time" +

    72                     "illegal value: " + entry.getValue());

    73             }

    74         }

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

    76     }

    77 }