test/jdk/jdk/jfr/event/compiler/TestAllocInNewTLAB.java
changeset 50113 caf115bb98ad
child 51214 67736b4846a0
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50112:7a2a740815b7 50113:caf115bb98ad
       
     1 /*
       
     2  * Copyright (c) 2013, 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.  Oracle designates this
       
     8  * particular file as subject to the "Classpath" exception as provided
       
     9  * by Oracle in the LICENSE file that accompanied this code.
       
    10  *
       
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    14  * version 2 for more details (a copy is included in the LICENSE file that
       
    15  * accompanied this code).
       
    16  *
       
    17  * You should have received a copy of the GNU General Public License version
       
    18  * 2 along with this work; if not, write to the Free Software Foundation,
       
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    20  *
       
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
       
    22  * or visit www.oracle.com if you need additional information or have any
       
    23  * questions.
       
    24  */
       
    25 
       
    26 package jdk.jfr.event.compiler;
       
    27 
       
    28 import static java.lang.Math.floor;
       
    29 import static jdk.test.lib.Asserts.assertGreaterThanOrEqual;
       
    30 import static jdk.test.lib.Asserts.assertLessThanOrEqual;
       
    31 
       
    32 import java.time.Duration;
       
    33 
       
    34 import jdk.jfr.Recording;
       
    35 import jdk.jfr.consumer.RecordedEvent;
       
    36 import jdk.test.lib.jfr.EventNames;
       
    37 import jdk.test.lib.jfr.Events;
       
    38 
       
    39 /*
       
    40  * @test
       
    41  * @summary Test that event is triggered when an object is allocated in a new TLAB.
       
    42  * @key jfr
       
    43  * @library /test/lib
       
    44  * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.compiler.TestAllocInNewTLAB
       
    45  * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -XX:-FastTLABRefill jdk.jfr.event.compiler.TestAllocInNewTLAB
       
    46  * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.compiler.TestAllocInNewTLAB
       
    47  */
       
    48 
       
    49 /**
       
    50  * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB)
       
    51  * an event will be triggered. The test is done for C1-compiler,
       
    52  * C2-compiler (-XX:-FastTLABRefill) and interpreted mode (-Xint).
       
    53  *
       
    54  * To force objects to be allocated in a new TLAB:
       
    55  *      the size of TLAB is set to 100k (-XX:TLABSize=100k);
       
    56  *      the size of allocated objects is set to 100k minus 16 bytes overhead;
       
    57  *      max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1),
       
    58  *          to provoke a new TLAB creation.
       
    59  */
       
    60 public class TestAllocInNewTLAB {
       
    61     private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB;
       
    62 
       
    63     private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array.
       
    64     private static final int OBJECT_SIZE  = 100 * 1024;
       
    65     private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops
       
    66     private static final int OBJECTS_TO_ALLOCATE = 100;
       
    67     private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName();
       
    68     private static final int INITIAL_TLAB_SIZE = 100 * 1024;
       
    69 
       
    70     // make sure allocation isn't dead code eliminated
       
    71     public static byte[] tmp;
       
    72 
       
    73     public static void main(String[] args) throws Exception {
       
    74         Recording recording = new Recording();
       
    75         recording.enable(EVENT_NAME).withThreshold(Duration.ofMillis(0));
       
    76 
       
    77         recording.start();
       
    78         System.gc();
       
    79         for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) {
       
    80             tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD];
       
    81         }
       
    82         recording.stop();
       
    83 
       
    84         int countAllTlabs = 0;  // Count all matching tlab allocations.
       
    85         int countFullTlabs = 0; // Count matching tlab allocations with full tlab size.
       
    86         for (RecordedEvent event : Events.fromRecording(recording)) {
       
    87             if (!EVENT_NAME.equals(event.getEventType().getName())) {
       
    88                 continue;
       
    89             }
       
    90             System.out.println("Event:" + event);
       
    91 
       
    92             long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue();
       
    93             long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue();
       
    94             String className = Events.assertField(event, "objectClass.name").notEmpty().getValue();
       
    95 
       
    96             boolean isMyEvent = Thread.currentThread().getId() == event.getThread().getJavaThreadId()
       
    97                  && className.equals(BYTE_ARRAY_CLASS_NAME)
       
    98                  && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT);
       
    99             if (isMyEvent) {
       
   100                 countAllTlabs++;
       
   101                 if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) {
       
   102                     countFullTlabs++;
       
   103                 }
       
   104             }
       
   105         }
       
   106 
       
   107         int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80);
       
   108         assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated");
       
   109         assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated");
       
   110 
       
   111         // For most GCs we expect the size of each tlab to be
       
   112         // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1.
       
   113         // G1 may use a smaller tlab size if the full tlab does not fit in the
       
   114         // selected memory region.
       
   115         //
       
   116         // For example, if a G1 memory region has room for 4.7 tlabs,
       
   117         // then the first 4 tlabs will have the expected size,
       
   118         // but the fifth tlab would only have a size of 0.7*expected.
       
   119         //
       
   120         // It is only the last tlab in each region that has a smaller size.
       
   121         // This means that at least 50% of the allocated tlabs should
       
   122         // have the expected size (1 full tlab, and 1 fractional tlab).
       
   123         assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs.");
       
   124     }
       
   125 
       
   126 }