lib/classpath/examples/gnu/classpath/examples/management/TestThread.java

   1 /* TestThread.java -- Tests the thread bean.
   2    Copyright (C) 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath examples.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA. */
  20
  21 package gnu.classpath.examples.management;
  22
  23 import java.lang.management.ManagementFactory;
  24 import java.lang.management.ThreadInfo;
  25 import java.lang.management.ThreadMXBean;
  26
  27 import java.util.Arrays;
  28
  29 public class TestThread
  30 {
  31
  32   public static void main(String[] args)
  33   {
  34     ThreadMXBean bean = ManagementFactory.getThreadMXBean();
  35     System.out.println("Bean: " + bean);
  36     System.out.println("Monitor deadlocked threads: " + bean.findMonitorDeadlockedThreads());
  37     long[] ids = bean.getAllThreadIds();
  38     System.out.println("Live thread ids: " + Arrays.toString(ids));
  39     boolean currentTimeMonitoring = bean.isCurrentThreadCpuTimeSupported();
  40     System.out.println("Current thread CPU time monitoring supported: " + currentTimeMonitoring);
  41     if (currentTimeMonitoring)
  42       {
  43         boolean timeEnabled = bean.isThreadCpuTimeEnabled();
  44         System.out.println("Is time monitoring enabled... " +
  45                            (timeEnabled ? "yes" : "no"));
  46         if (!timeEnabled)
  47           {
  48             System.out.println("Enabling...");
  49             bean.setThreadCpuTimeEnabled(true);
  50             timeEnabled = bean.isThreadCpuTimeEnabled();
  51             System.out.println("Should now be enabled... " +
  52                            (timeEnabled ? "yes" : "no"));
  53           }
  54         if (timeEnabled)
  55           {
  56             System.out.println("Current thread CPU time: "
  57                                + bean.getCurrentThreadCpuTime()
  58                                + "ns");
  59             System.out.println("Current thread user time: "
  60                                + bean.getCurrentThreadUserTime()
  61                                + "ns");
  62           }
  63       }
  64     System.out.println("Daemon thread count: " + bean.getDaemonThreadCount());
  65     System.out.println("Peak thread count: " + bean.getPeakThreadCount());
  66     System.out.println("Resetting...");
  67     bean.resetPeakThreadCount();
  68     System.out.println("Peak thread count: " + bean.getPeakThreadCount());
  69     System.out.println("Thread count: " + bean.getThreadCount());
  70     boolean timeMonitoring = bean.isThreadCpuTimeSupported();
  71     System.out.println("Thread CPU time monitoring supported: " + timeMonitoring);
  72     if (timeMonitoring)
  73       {
  74         for (int a = 0; a < ids.length; ++a)
  75           {
  76             System.out.println("Thread " + a
  77                                + " CPU time: "
  78                                + bean.getThreadCpuTime(ids[a]) + "ns");
  79             System.out.println("Thread "
  80                                + a + " user time: "
  81                                + bean.getThreadUserTime(ids[a]) + "ns");
  82           }
  83       }
  84     System.out.println("Current thread info: "
  85                        + bean.getThreadInfo(Thread.currentThread().getId()));
  86     System.out.println("All thread info: " + Arrays.toString(bean.getThreadInfo(ids)));
  87     System.out.println("Total started threads: " + bean.getTotalStartedThreadCount());
  88     boolean contentionMonitoring = bean.isThreadContentionMonitoringSupported();
  89     System.out.println("Thread contention monitoring supported: " + contentionMonitoring);
  90     if (contentionMonitoring)
  91       {
  92         boolean contentionEnabled = bean.isThreadContentionMonitoringEnabled();
  93         System.out.println("Thread contention monitoring shouldn't be enabled... " +
  94                            (contentionEnabled ? "but it is" : "true"));
  95         if (!contentionEnabled)
  96           {
  97             System.out.println("Enabling...");
  98             bean.setThreadContentionMonitoringEnabled(true);
  99             contentionEnabled = bean.isThreadContentionMonitoringEnabled();
 100             System.out.println("Should now be enabled... " +
 101                                (contentionEnabled ? "it is" : "nope"));
 102           }
 103         if (contentionEnabled)
 104           {
 105             ThreadInfo[] info = bean.getThreadInfo(ids);
 106             for (int a = 0; a < info.length; ++a)
 107               {
 108                 System.out.println("Blocked time for thread "
 109                                    + info[a].getThreadId() + ": "
 110                                    + info[a].getBlockedTime() + "ms");
 111                 System.out.println("Waited time for thread "
 112                                    + info[a].getThreadId() + ": "
 113                                    + info[a].getWaitedTime() + "ms");
 114               }
 115           }
 116       }
 117   }
 118 }