1 /*

     2  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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

    21  * questions.

    22  */

    23 

    24 /* @test

    25  * @bug 6606598

    26  * @summary Unit test for java.nio.BufferPoolMXBean

    27  * @run main/othervm Basic

    28  */

    29 

    30 import java.nio.ByteBuffer;

    31 import java.nio.MappedByteBuffer;

    32 import java.nio.BufferPoolMXBean;

    33 import java.nio.channels.FileChannel;

    34 import java.io.File;

    35 import java.io.RandomAccessFile;

    36 import java.lang.management.ManagementFactory;

    37 import javax.management.MBeanServer;

    38 import javax.management.ObjectName;

    39 import java.util.*;

    40 

    41 public class Basic {

    42 

    43     // static fields to ensure buffers aren't GC'ed

    44     static List<ByteBuffer> buffers;

    45     static MappedByteBuffer mbb;

    46 

    47     // check counters

    48     static void check(List<BufferPoolMXBean> pools,

    49                       int minBufferCount,

    50                       long minTotalCapacity)

    51     {

    52         int bufferCount = 0;

    53         long totalCap = 0;

    54         long totalMem = 0;

    55         for (BufferPoolMXBean pool: pools) {

    56             bufferCount += pool.getCount();

    57             totalCap += pool.getTotalCapacity();

    58             totalMem += pool.getMemoryUsed();

    59         }

    60         if (bufferCount < minBufferCount)

    61             throw new RuntimeException("Count less than expected");

    62         if (totalMem < minTotalCapacity)

    63             throw new RuntimeException("Memory usage less than expected");

    64         if (totalCap < minTotalCapacity)

    65             throw new RuntimeException("Total capacity less than expected");

    66     }

    67 

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

    69         Random rand = new Random();

    70 

    71         // allocate a few direct buffers

    72         int bufferCount = 5 + rand.nextInt(20);

    73         buffers = new ArrayList<ByteBuffer>(bufferCount);

    74         long totalCapacity = 0L;

    75         for (int i=0; i<bufferCount; i++) {

    76             int cap = 1024 + rand.nextInt(4096);

    77             buffers.add( ByteBuffer.allocateDirect(cap) );

    78             totalCapacity += cap;

    79         }

    80 

    81         // map a file

    82         File f = File.createTempFile("blah", null);

    83         f.deleteOnExit();

    84         RandomAccessFile raf = new RandomAccessFile(f, "rw");

    85         FileChannel fc = raf.getChannel();

    86         mbb = fc.map(FileChannel.MapMode.READ_WRITE, 10, 100);

    87         bufferCount++;

    88         totalCapacity += mbb.capacity();

    89 

    90         // direct

    91         List<BufferPoolMXBean> pools =

    92             ManagementFactory.getPlatformMXBeans(BufferPoolMXBean.class);

    93         check(pools, bufferCount, totalCapacity);

    94 

    95         // using MBeanServer

    96         MBeanServer server = ManagementFactory.getPlatformMBeanServer();

    97         Set<ObjectName> mbeans = server.queryNames(

    98             new ObjectName("java.nio:type=BufferPool,*"), null);

    99         pools = new ArrayList<BufferPoolMXBean>();

   100         for (ObjectName name: mbeans) {

   101             BufferPoolMXBean pool = ManagementFactory

   102                 .newPlatformMXBeanProxy(server, name.toString(), BufferPoolMXBean.class);

   103             pools.add(pool);

   104         }

   105         check(pools, bufferCount, totalCapacity);

   106     }

   107 }