GetClassInitializationTime.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/*
 * @test
 * @bug     4858522
 * @summary Basic unit test of HotspotClassLoadingMBean.getClassInitializationTime()
 * @author  Steve Bohne
 *
 * @run main/othervm -XX:+UsePerfData GetClassInitializationTime
 */

/*
 * This test is just a sanity check and does not check for the correct value.
 */

import sun.management.*;

public class GetClassInitializationTime {

    private static HotspotClassLoadingMBean mbean =
        (HotspotClassLoadingMBean)ManagementFactoryHelper.getHotspotClassLoadingMBean();

    // Careful with these values.
    private static final long MIN_TIME_FOR_PASS = 1;
    private static final long MAX_TIME_FOR_PASS = Long.MAX_VALUE;

    private static boolean trace = false;

    public static void main(String args[]) throws Exception {
        if (args.length > 0 && args[0].equals("trace")) {
            trace = true;
        }

        long time = mbean.getClassInitializationTime();

        if (trace) {
            System.out.println("Class initialization time (ms): " + time);
        }

        if (time < MIN_TIME_FOR_PASS || time > MAX_TIME_FOR_PASS) {
            throw new RuntimeException("Class initialization time " +
                                       "illegal value: " + time + " ms " +
                                       "(MIN = " + MIN_TIME_FOR_PASS + "; " +
                                       "MAX = " + MAX_TIME_FOR_PASS + ")");
        }

        // Load a class and make sure the time increases
        Class.forName("ClassToInitialize");

        long time2 = mbean.getClassInitializationTime();

        if (trace) {
            System.out.println("Class initialization time2 (ms): " + time2);
        }

        if (time2 <= time) {
            throw new RuntimeException("Class initialization time " +
                                       "did not increase when class loaded " +
                                       "(time = " + time + "; " +
                                       "time2 = " + time2 + ")");
        }

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

// This class should just cause the initialization timer to run
class ClassToInitialize {
    static {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException ie) {
            // do nothing
        }
    }
}