1 /*

     2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

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

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 import java.lang.management.ManagementFactory;

    25 import utils.GarbageProducer;

    26 import common.TmTool;

    27 import utils.JstatResults;

    28 

    29 /**

    30  * Base class for jstat testing which uses GarbageProducer to allocate garbage.

    31  */

    32 public class GarbageProducerTest {

    33 

    34     // Iterations of measurement to get consistent value of counters and jstat.

    35     private final static int ITERATIONS = 10;

    36     private final static float TARGET_MEMORY_USAGE = 0.7f;

    37     private final static float MEASUREMENT_TOLERANCE = 0.05f;

    38     private final GarbageProducer garbageProducer;

    39     private final TmTool<? extends JstatResults> jstatTool;

    40 

    41     public GarbageProducerTest(TmTool<? extends JstatResults> tool) {

    42         garbageProducer = new GarbageProducer(TARGET_MEMORY_USAGE);

    43         // We will be running jstat tool

    44         jstatTool = tool;

    45     }

    46 

    47     public void run() throws Exception {

    48         // Run once and get the  results asserting that they are reasonable

    49         JstatResults measurement1 = jstatTool.measure();

    50         measurement1.assertConsistency();

    51         // Eat metaspace and heap then run the tool again and get the results  asserting that they are reasonable

    52         System.gc();

    53         garbageProducer.allocateMetaspaceAndHeap();

    54         // Collect garbage. Also update VM statistics

    55         System.gc();

    56         int i = 0;

    57         long collectionCountBefore = getCollectionCount();

    58         JstatResults measurement2 = jstatTool.measure();

    59         do {

    60             System.out.println("Measurement #" + i);

    61             long currentCounter = getCollectionCount();

    62             // Check if GC cycle occured during measurement

    63             if (currentCounter == collectionCountBefore) {

    64                 measurement2.assertConsistency();

    65                 checkOldGenMeasurement(measurement2);

    66                 return;

    67             } else {

    68                 System.out.println("GC happened during measurement.");

    69             }

    70             collectionCountBefore = getCollectionCount();

    71             measurement2 = jstatTool.measure();

    72 

    73         } while (i++ < ITERATIONS);

    74         // Checking will be performed without consistency guarantee.

    75         checkOldGenMeasurement(measurement2);

    76     }

    77 

    78     private void checkOldGenMeasurement(JstatResults measurement2) {

    79         float oldGenAllocationRatio = garbageProducer.getOldGenAllocationRatio() - MEASUREMENT_TOLERANCE;

    80         // Assert that space has been utilized accordingly

    81         JstatResults.assertSpaceUtilization(measurement2, TARGET_MEMORY_USAGE, oldGenAllocationRatio);

    82     }

    83 

    84     private static long getCollectionCount() {

    85         return ManagementFactory.getGarbageCollectorMXBeans().stream()

    86                 .mapToLong(b -> b.getCollectionCount())

    87                 .sum();

    88     }

    89 }