1 /*
2 * Copyright (c) 2017, Google 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 package MyPackage;
25
26 /**
27 * @test
28 * @build Frame HeapMonitor
29 * @summary Verifies the JVMTI Heap Monitor Statistics
30 * @compile HeapMonitorStatObjectCorrectnessTest.java
31 * @run main/othervm/native -agentlib:HeapMonitor MyPackage.HeapMonitorStatObjectCorrectnessTest
32 */
33
34 /** This test is checking the object allocation path works with heap sampling. */
35 public class HeapMonitorStatObjectCorrectnessTest {
36
37 // Do 200000 iterations and expect maxIteration / multiplier samples.
38 private static final int maxIteration = 200000;
39 private static BigObject obj;
40
41 private native static boolean statsHaveExpectedNumberSamples(int expected, int percentError);
42
43 private static void allocate() {
44 for (int j = 0; j < maxIteration; j++) {
45 obj = new BigObject();
46 }
47 }
48
49 public static void main(String[] args) {
50 final int sizeObject = 1400;
51
52 // 111 is as good a number as any.
53 final int samplingMultiplier = 111;
54 HeapMonitor.enableSampling(samplingMultiplier * sizeObject);
55
56 if (!HeapMonitor.areSamplingStatisticsZero()) {
57 throw new RuntimeException("Statistics should be null to begin with.");
58 }
59
60 allocate();
61
62 // For simplifications, the code is allocating:
63 // (BigObject size) * maxIteration.
64 //
65 // We ignore the class memory usage apart from field memory usage for BigObject. BigObject
66 // allocates 250 long, so 2000 bytes, so whatever is used for the class is negligible.
67 //
68 // That means that with maxIterations, the loop in the method allocate requests:
69 // maxIterations * 2000 bytes.
70 //
71 // Via the enable sampling, the code requests a sample every samplingMultiplier * sizeObject bytes.
72 //
73 // Therefore, the expected sample number is:
74 // (maxIterations * sizeObject) / (samplingMultiplier * sizeObject);
75 //
76 // Which becomes:
77 // maxIterations / samplingMultiplier
78 double expected = maxIteration;
79 expected /= samplingMultiplier;
80
81 // 10% error ensures a sanity test without becoming flaky.
82 if (!HeapMonitor.statsHaveExpectedNumberSamples((int) expected, 10)) {
83 throw new RuntimeException("Statistics should show about " + expected + " samples.");
84 }
85
86 HeapMonitor.disableSampling();
87 }
88
89 /**
90 * Big class on purpose to just be able to ignore the class memory space overhead.
91 *
92 * Class contains 175 long fields, so 175 * 8 = 1400 bytes.
93 */
94 private static class BigObject {
95 private long a0_0, a0_1, a0_2, a0_3, a0_4, a0_5, a0_6, a0_7, a0_8, a0_9;
96 private long a1_0, a1_1, a1_2, a1_3, a1_4, a1_5, a1_6, a1_7, a1_8, a1_9;
97 private long a2_0, a2_1, a2_2, a2_3, a2_4, a2_5, a2_6, a2_7, a2_8, a2_9;
98 private long a3_0, a3_1, a3_2, a3_3, a3_4, a3_5, a3_6, a3_7, a3_8, a3_9;
99 private long a4_0, a4_1, a4_2, a4_3, a4_4, a4_5, a4_6, a4_7, a4_8, a4_9;
100 private long a5_0, a5_1, a5_2, a5_3, a5_4, a5_5, a5_6, a5_7, a5_8, a5_9;
101 private long a6_0, a6_1, a6_2, a6_3, a6_4, a6_5, a6_6, a6_7, a6_8, a6_9;
102 private long a7_0, a7_1, a7_2, a7_3, a7_4, a7_5, a7_6, a7_7, a7_8, a7_9;
103 private long a8_0, a8_1, a8_2, a8_3, a8_4, a8_5, a8_6, a8_7, a8_8, a8_9;
104 private long a9_0, a9_1, a9_2, a9_3, a9_4, a9_5, a9_6, a9_7, a9_8, a9_9;
105 private long a10_0, a10_1, a10_2, a10_3, a10_4, a10_5, a10_6, a10_7, a10_8, a10_9;
106 private long a11_0, a11_1, a11_2, a11_3, a11_4, a11_5, a11_6, a11_7, a11_8, a11_9;
107 private long a12_0, a12_1, a12_2, a12_3, a12_4, a12_5, a12_6, a12_7, a12_8, a12_9;
108 private long a13_0, a13_1, a13_2, a13_3, a13_4, a13_5, a13_6, a13_7, a13_8, a13_9;
109 private long a14_0, a14_1, a14_2, a14_3, a14_4, a14_5, a14_6, a14_7, a14_8, a14_9;
110 private long a15_0, a15_1, a15_2, a15_3, a15_4, a15_5, a15_6, a15_7, a15_8, a15_9;
111 private long a16_0, a16_1, a16_2, a16_3, a16_4, a16_5, a16_6, a16_7, a16_8, a16_9;
112 private long a17_0, a17_1, a17_2, a17_3, a17_4;
113 }
114 }