TestThread.java

/* TestThread.java -- Tests the thread bean.
   Copyright (C) 2006 Free Software Foundation, Inc.

This file is part of GNU Classpath examples.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA. */

package gnu.classpath.examples.management;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;

import java.util.Arrays;

public class TestThread
{

  public static void main(String[] args)
  {
    ThreadMXBean bean = ManagementFactory.getThreadMXBean();
    System.out.println("Bean: " + bean);
    System.out.println("Monitor deadlocked threads: " + bean.findMonitorDeadlockedThreads());
    long[] ids = bean.getAllThreadIds();
    System.out.println("Live thread ids: " + Arrays.toString(ids));
    boolean currentTimeMonitoring = bean.isCurrentThreadCpuTimeSupported();
    System.out.println("Current thread CPU time monitoring supported: " + currentTimeMonitoring);
    if (currentTimeMonitoring)
      {
	boolean timeEnabled = bean.isThreadCpuTimeEnabled();
	System.out.println("Is time monitoring enabled... " + 
			   (timeEnabled ? "yes" : "no"));
	if (!timeEnabled)
	  {
	    System.out.println("Enabling...");
	    bean.setThreadCpuTimeEnabled(true);
	    timeEnabled = bean.isThreadCpuTimeEnabled();
	    System.out.println("Should now be enabled... " +
			   (timeEnabled ? "yes" : "no"));
	  }
	if (timeEnabled)
	  {
	    System.out.println("Current thread CPU time: " 
			       + bean.getCurrentThreadCpuTime()
			       + "ns");
	    System.out.println("Current thread user time: " 
			       + bean.getCurrentThreadUserTime()
			       + "ns");
	  }
      }
    System.out.println("Daemon thread count: " + bean.getDaemonThreadCount());
    System.out.println("Peak thread count: " + bean.getPeakThreadCount());
    System.out.println("Resetting...");
    bean.resetPeakThreadCount();
    System.out.println("Peak thread count: " + bean.getPeakThreadCount());
    System.out.println("Thread count: " + bean.getThreadCount());
    boolean timeMonitoring = bean.isThreadCpuTimeSupported();
    System.out.println("Thread CPU time monitoring supported: " + timeMonitoring);
    if (timeMonitoring)
      {
	for (int a = 0; a < ids.length; ++a)
	  {
	    System.out.println("Thread " + a 
			       + " CPU time: " 
			       + bean.getThreadCpuTime(ids[a]) + "ns");
	    System.out.println("Thread " 
			       + a + " user time: " 
			       + bean.getThreadUserTime(ids[a]) + "ns");
	  }
      }
    System.out.println("Current thread info: "
		       + bean.getThreadInfo(Thread.currentThread().getId()));
    System.out.println("All thread info: " + Arrays.toString(bean.getThreadInfo(ids)));
    System.out.println("Total started threads: " + bean.getTotalStartedThreadCount());
    boolean contentionMonitoring = bean.isThreadContentionMonitoringSupported();
    System.out.println("Thread contention monitoring supported: " + contentionMonitoring);
    if (contentionMonitoring)
      {
	boolean contentionEnabled = bean.isThreadContentionMonitoringEnabled();
	System.out.println("Thread contention monitoring shouldn't be enabled... " + 
			   (contentionEnabled ? "but it is" : "true"));
	if (!contentionEnabled)
	  {
	    System.out.println("Enabling...");
	    bean.setThreadContentionMonitoringEnabled(true);
	    contentionEnabled = bean.isThreadContentionMonitoringEnabled();
	    System.out.println("Should now be enabled... " +
			       (contentionEnabled ? "it is" : "nope"));
	  }
	if (contentionEnabled)
	  {
	    ThreadInfo[] info = bean.getThreadInfo(ids);
	    for (int a = 0; a < info.length; ++a)
	      {
		System.out.println("Blocked time for thread " 
				   + info[a].getThreadId() + ": " 
				   + info[a].getBlockedTime() + "ms");
		System.out.println("Waited time for thread " 
				   + info[a].getThreadId() + ": " 
				   + info[a].getWaitedTime() + "ms");
	      }
	  }
      }
  }
}