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

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

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

 *

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/*

 * @test

 * @bug     4997799

 * @summary Basic test of ThreadMXBean.getThreadUserTime and

 *          getCurrentThreadUserTime.

 * @author  Mandy Chung

 */

import java.lang.management.*;

public class ThreadUserTime {

    private static ThreadMXBean mbean = ManagementFactory.getThreadMXBean();

    private static boolean testFailed = false;

    private static boolean done = false;

    private static Object obj = new Object();

    private static final int NUM_THREADS = 10;

    private static Thread[] threads = new Thread[NUM_THREADS];

    private static long[] times = new long[NUM_THREADS];

    // careful about this value

    private static final int DELTA = 100;

    public static void main(String[] argv)

        throws Exception {

        if (!mbean.isCurrentThreadCpuTimeSupported()) {

            return;

        }

        // disable user time

        if (mbean.isThreadCpuTimeEnabled()) {

            mbean.setThreadCpuTimeEnabled(false);

        }

        Thread curThread = Thread.currentThread();

        long t = mbean.getCurrentThreadUserTime();

        if (t != -1) {

            throw new RuntimeException("Invalid CurrenThreadUserTime returned = " +

                t + " expected = -1");

        }

        if (mbean.isThreadCpuTimeSupported()) {

            long t1 = mbean.getThreadUserTime(curThread.getId());

            if (t1 != -1) {

                throw new RuntimeException("Invalid ThreadUserTime returned = " +

                    t1 + " expected = -1");

            }

        }

        // Enable CPU Time measurement

        if (!mbean.isThreadCpuTimeEnabled()) {

            mbean.setThreadCpuTimeEnabled(true);

        }

        if (!mbean.isThreadCpuTimeEnabled()) {

            throw new RuntimeException("ThreadUserTime is expected to be enabled");

        }

        long time = mbean.getCurrentThreadUserTime();

        if (time < 0) {

            throw new RuntimeException("Invalid user time returned = " + time);

        }

        if (!mbean.isThreadCpuTimeSupported()) {

            return;

        }

        // Expected to be time1 >= time

        long time1 = mbean.getThreadUserTime(curThread.getId());

        if (time1 < time) {

            throw new RuntimeException("User time " + time1 +

                " expected >= " + time);

        }

        System.out.println(curThread.getName() +

            " Current Thread User Time = " + time +

            " user time = " + time1);

        for (int i = 0; i < NUM_THREADS; i++) {

            threads[i] = new MyThread("MyThread-" + i);

            threads[i].start();

        }

        waitUntilThreadBlocked();

        for (int i = 0; i < NUM_THREADS; i++) {

            times[i] = mbean.getThreadUserTime(threads[i].getId());

        }

        goSleep(200);

        for (int i = 0; i < NUM_THREADS; i++) {

            long newTime = mbean.getThreadUserTime(threads[i].getId());

            if (times[i] > newTime) {

                throw new RuntimeException("TEST FAILED: " +

                    threads[i].getName() +

                    " previous user user time = " + times[i] +

                    " > current user user time = " + newTime);

            }

            if ((times[i] + DELTA) < newTime) {

                throw new RuntimeException("TEST FAILED: " +

                    threads[i].getName() +

                    " user time = " + newTime +

                    " previous user time " + times[i] +

                    " out of expected range");

            }

            System.out.println(threads[i].getName() +

                " Previous User Time = " + times[i] +

                " Current User time = " + newTime);

        }

        synchronized (obj) {

            done = true;

            obj.notifyAll();

        }

        for (int i = 0; i < NUM_THREADS; i++) {

            try {

                threads[i].join();

            } catch (InterruptedException e) {

                System.out.println("Unexpected exception is thrown.");

                e.printStackTrace(System.out);

                testFailed = true;

                break;

            }

        }

        if (testFailed) {

            throw new RuntimeException("TEST FAILED");

        }

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

    }

    private static void goSleep(long ms) throws Exception {

        try {

            Thread.sleep(ms);

        } catch (InterruptedException e) {

            System.out.println("Unexpected exception is thrown.");

            throw e;

        }

    }

    private static void waitUntilThreadBlocked()

        throws Exception {

        int count = 0;

        while (count != NUM_THREADS) {

            goSleep(100);

            count = 0;

            for (int i = 0; i < NUM_THREADS; i++) {

                ThreadInfo info = mbean.getThreadInfo(threads[i].getId());

                if (info.getThreadState() == Thread.State.WAITING) {

                    count++;

                }

            }

        }

    }

    static class MyThread extends Thread {

        public MyThread(String name) {

            super(name);

        }

        public void run() {

            double sum = 0;

            for (int i = 0; i < 5000; i++) {

               double r = Math.random();

               double x = Math.pow(3, r);

               sum += x - r;

            }

            synchronized (obj) {

                while (!done) {

                    try {

                        obj.wait();

                    } catch (InterruptedException e) {

                        System.out.println("Unexpected exception is thrown.");

                        e.printStackTrace(System.out);

                        testFailed = true;

                        break;

                    }

                }

            }

            sum = 0;

            for (int i = 0; i < 5000; i++) {

               double r = Math.random();

               double x = Math.pow(3, r);

               sum += x - r;

            }

            long time1 = mbean.getCurrentThreadCpuTime();

            long utime1 = mbean.getCurrentThreadUserTime();

            long time2 = mbean.getThreadCpuTime(getId());

            long utime2 = mbean.getThreadUserTime(getId());

            System.out.println(getName() + ":");

            System.out.println("CurrentThreadUserTime = " + utime1 +

                " ThreadUserTime = " + utime2);

            System.out.println("CurrentThreadCpuTime  = " + time1 +

                " ThreadCpuTime  = " + time2);

            if (time1 > time2) {

                throw new RuntimeException("TEST FAILED: " + getName() +

                    " CurrentThreadCpuTime = " + time1 +

                    " > ThreadCpuTime = " + time2);

            }

            if (utime1 > utime2) {

                throw new RuntimeException("TEST FAILED: " + getName() +

                    " CurrentThreadUserTime = " + utime1 +

                    " > ThreadUserTime = " + utime2);

            }

        }

    }

}