1 /*

     2  * Copyright (c) 2018, 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 /**

    25  * @test TestPeriodicCollection

    26  * @requires vm.gc.G1

    27  * @requires vm.compMode != "Xcomp"

    28  * @summary Verify that heap shrinks when the application is idle.

    29  * @library /test/lib /

    30  * @modules java.base/jdk.internal.misc

    31  * @modules java.management/sun.management

    32  * @run main/othervm -XX:MaxNewSize=32M -XX:InitialHeapSize=48M -Xmx128M -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=25 -XX:+UseG1GC -XX:G1PeriodicGCInterval=3000 -XX:+G1PeriodicGCInvokesConcurrent -Xlog:gc,gc+periodic=debug,gc+ergo+heap=debug TestPeriodicCollection

    33  * @run main/othervm -XX:MaxNewSize=32M -XX:InitialHeapSize=48M -Xmx128M -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=25 -XX:+UseG1GC -XX:G1PeriodicGCInterval=3000 -XX:-G1PeriodicGCInvokesConcurrent -Xlog:gc,gc+periodic=debug,gc+ergo+heap=debug TestPeriodicCollection

    34  */

    35 

    36 import com.sun.management.HotSpotDiagnosticMXBean;

    37 

    38 import gc.testlibrary.Helpers;

    39 

    40 import java.lang.management.GarbageCollectorMXBean;

    41 import java.lang.management.ManagementFactory;

    42 import java.lang.management.MemoryUsage;

    43 import java.text.NumberFormat;

    44 import static jdk.test.lib.Asserts.*;

    45 

    46 public class TestPeriodicCollection {

    47 

    48     public static final String MIN_FREE_RATIO_FLAG_NAME = "MinHeapFreeRatio";

    49     public static final String MAX_FREE_RATIO_FLAG_NAME = "MaxHeapFreeRatio";

    50 

    51     private static final int IDLE_TIME = 7 * 1000;

    52 

    53     private static boolean gcOccurred() {

    54         for (GarbageCollectorMXBean b : ManagementFactory.getGarbageCollectorMXBeans()) {

    55             if (b.getCollectionCount() != 0) {

    56                 return true;

    57             }

    58         }

    59         return false;

    60     }

    61 

    62     public static void main(String[] args) {

    63         MemoryUsage muInitial = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();

    64         MemoryUsagePrinter.printMemoryUsage("initial", muInitial);

    65 

    66         if (gcOccurred()) {

    67           System.out.println("At least one garbage collection occurred. Exiting as this may have already shrunk the heap.");

    68           return;

    69         }

    70 

    71         try {

    72             Thread.sleep(IDLE_TIME);

    73         } catch (InterruptedException ie) {

    74             System.err.println("Skipped. Failed to wait for idle collection");

    75         }

    76 

    77         MemoryUsage muAfter = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();

    78         MemoryUsagePrinter.printMemoryUsage("after", muAfter);

    79 

    80         assertLessThan(muAfter.getCommitted(), muInitial.getCommitted(), String.format(

    81                 "committed free heap size is not less than committed full heap size, heap hasn't been shrunk?%n"

    82                 + "%s = %s%n%s = %s",

    83                 MIN_FREE_RATIO_FLAG_NAME,

    84                 ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class)

    85                     .getVMOption(MIN_FREE_RATIO_FLAG_NAME).getValue(),

    86                 MAX_FREE_RATIO_FLAG_NAME,

    87                 ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class)

    88                     .getVMOption(MAX_FREE_RATIO_FLAG_NAME).getValue()

    89         ));

    90     }

    91 }

    92 

    93 /**

    94  * Prints memory usage to standard output

    95  */

    96 class MemoryUsagePrinter {

    97 

    98     public static final NumberFormat NF = Helpers.numberFormatter();

    99 

   100     public static void printMemoryUsage(String label, MemoryUsage memusage) {

   101         float freeratio = 1f - (float) memusage.getUsed() / memusage.getCommitted();

   102         System.out.format("[%-24s] init: %-7s, used: %-7s, comm: %-7s, freeRatio ~= %.1f%%%n",

   103                 label,

   104                 NF.format(memusage.getInit()),

   105                 NF.format(memusage.getUsed()),

   106                 NF.format(memusage.getCommitted()),

   107                 freeratio * 100

   108         );

   109     }

   110 }