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 *
44 * @library /lib /
45 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.compiler.TestAllocInNewTLAB
46 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -XX:-FastTLABRefill jdk.jfr.event.compiler.TestAllocInNewTLAB
47 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.compiler.TestAllocInNewTLAB
48 */
49
50 /**
51 * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB)
52 * an event will be triggered. The test is done for C1-compiler,
53 * C2-compiler (-XX:-FastTLABRefill) and interpreted mode (-Xint).
54 *
55 * To force objects to be allocated in a new TLAB:
56 * the size of TLAB is set to 100k (-XX:TLABSize=100k);
57 * the size of allocated objects is set to 100k minus 16 bytes overhead;
58 * max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1),
59 * to provoke a new TLAB creation.
60 */
61 public class TestAllocInNewTLAB {
62 private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB;
63
64 private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array.
65 private static final int OBJECT_SIZE = 100 * 1024;
66 private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops
67 private static final int OBJECTS_TO_ALLOCATE = 100;
68 private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName();
69 private static final int INITIAL_TLAB_SIZE = 100 * 1024;
70
71 // make sure allocation isn't dead code eliminated
72 public static byte[] tmp;
73
74 public static void main(String[] args) throws Exception {
75 Recording recording = new Recording();
76 recording.enable(EVENT_NAME).withThreshold(Duration.ofMillis(0));
77
78 recording.start();
79 System.gc();
80 for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) {
81 tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD];
82 }
83 recording.stop();
84
85 int countAllTlabs = 0; // Count all matching tlab allocations.
86 int countFullTlabs = 0; // Count matching tlab allocations with full tlab size.
87 for (RecordedEvent event : Events.fromRecording(recording)) {
88 if (!EVENT_NAME.equals(event.getEventType().getName())) {
89 continue;
90 }
91 System.out.println("Event:" + event);
92
93 long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue();
94 long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue();
95 String className = Events.assertField(event, "objectClass.name").notEmpty().getValue();
96
97 boolean isMyEvent = Thread.currentThread().getId() == event.getThread().getJavaThreadId()
98 && className.equals(BYTE_ARRAY_CLASS_NAME)
99 && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT);
100 if (isMyEvent) {
101 countAllTlabs++;
102 if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) {
103 countFullTlabs++;
104 }
105 }
106 }
107
108 int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80);
109 assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated");
110 assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated");
111
112 // For most GCs we expect the size of each tlab to be
113 // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1.
114 // G1 may use a smaller tlab size if the full tlab does not fit in the
115 // selected memory region.
116 //
117 // For example, if a G1 memory region has room for 4.7 tlabs,
118 // then the first 4 tlabs will have the expected size,
119 // but the fifth tlab would only have a size of 0.7*expected.
120 //
121 // It is only the last tlab in each region that has a smaller size.
122 // This means that at least 50% of the allocated tlabs should
123 // have the expected size (1 full tlab, and 1 fractional tlab).
124 assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs.");
125 }
126
127 }