Example usage for java.lang.management ThreadMXBean setThreadCpuTimeEnabled

Introduction

In this page you can find the example usage for java.lang.management ThreadMXBean setThreadCpuTimeEnabled.

Prototype

public void setThreadCpuTimeEnabled(boolean enable);

Source Link

Document

Enables or disables thread CPU time measurement.

Usage

From source file:eu.planets_project.tb.gui.backing.exp.ExpTypeMigrate.java

public static void main(String args[]) {

    Properties p = System.getProperties();

    ByteArrayOutputStream byos = new ByteArrayOutputStream();
    try {/*from w w w. j a  va2 s  .c o  m*/
        p.storeToXML(byos, "Automatically generated for PLANETS Service ", "UTF-8");
        String res = byos.toString("UTF-8");
        System.out.println(res);
    } catch (IOException e) {
        e.printStackTrace();
    }

    // This.
    List<String> pl = new ArrayList<String>();
    for (Object key : p.keySet()) {
        pl.add((String) key);
    }
    Collections.sort(pl);

    //
    for (String key : pl) {
        System.out.println(key + " = " + p.getProperty(key));
    }

    /*
     * http://java.sun.com/j2se/1.5.0/docs/api/java/lang/management/ThreadMXBean.html#getCurrentThreadCpuTime()
     * 
     * http://www.java-forums.org/new-java/5303-how-determine-cpu-usage-using-java.html
     * 
     */

    ThreadMXBean TMB = ManagementFactory.getThreadMXBean();
    int mscale = 1000000;
    long time = 0, time2 = 0;
    long cput = 0, cput2 = 0;
    double cpuperc = -1;

    //Begin loop.
    for (int i = 0; i < 10; i++) {

        if (TMB.isThreadCpuTimeSupported()) {
            if (!TMB.isThreadCpuTimeEnabled()) {
                TMB.setThreadCpuTimeEnabled(true);
            }

            //                if(new Date().getTime() * mscale - time > 1000000000) //Reset once per second
            //                {
            System.out.println("Resetting...");
            time = System.currentTimeMillis() * mscale;
            cput = TMB.getCurrentThreadCpuTime();
            //                cput = TMB.getCurrentThreadUserTime();
            //                }

        }

        //Do cpu intensive stuff
        for (int k = 0; k < 10; k++) {
            for (int j = 0; j < 100000; j++) {
                double a = Math.pow(i, j);
                double b = a / j + Math.random();
                a = b * Math.random();
                b = a * Math.random();
            }

            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }

        if (TMB.isThreadCpuTimeSupported()) {
            //                if(new Date().getTime() * mscale - time != 0) {
            cput2 = TMB.getCurrentThreadCpuTime();
            System.out.println("cpu: " + (cput2 - cput) / (1000.0 * mscale));
            //                cput2 = TMB.getCurrentThreadUserTime();

            time2 = System.currentTimeMillis() * mscale;
            System.out.println("time: " + (time2 - time) / (1000.0 * mscale));

            cpuperc = 100.0 * (cput2 - cput) / (double) (time2 - time);
            System.out.println("cpu perc = " + cpuperc);
            //                }
        }
        //End Loop
    }
    System.out.println("Done.");
}

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From source file:io.pcp.parfait.benchmark.CPUThreadTest.java

private void runBenchmark(boolean cpuTracingEnabled, CPUThreadTestRunner.CpuLookupMethod cpuLookupMethod) {
    ExecutorService executorService = Executors.newFixedThreadPool(numThreads);
    List<CPUThreadTestRunner> executions = newArrayList();

    ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
    threadBean.setThreadCpuTimeEnabled(cpuTracingEnabled);

    threadBean.setThreadContentionMonitoringEnabled(true);

    long begin = currentTimeMillis();

    for (int i = 0; i < numThreads; i++) {
        CPUThreadTestRunner cpuThreadTestRunner = new CPUThreadTestRunner(iterations, cpuLookupMethod);
        executorService.execute(cpuThreadTestRunner);
        executions.add(cpuThreadTestRunner);
    }/*from w  w w. ja va2s.c o  m*/

    awaitExecutionCompletion(executorService);

    long end = currentTimeMillis();
    long timeTakenms = end - begin;

    report(executions, timeTakenms, iterations, cpuTracingEnabled, cpuLookupMethod);
}

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