1 /*
2 * Copyright (c) 2016, 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 #include "precompiled.hpp"
25 #include "utilities/macros.hpp"
26 #include "gc/g1/g1Predictions.hpp"
27 #include "unittest.hpp"
28
29 #if INCLUDE_ALL_GCS
30
31 TEST_VM(gc, testPredictionsBasic) {
32 double const epsilon = 1e-6;
33
34 // Some basic formula tests with confidence = 0.0
35 G1Predictions predictor(0.0);
36 TruncatedSeq s;
37
38 double p0 = predictor.get_new_prediction(&s);
39 ASSERT_LT(p0, epsilon)
40 << "Initial prediction of empty sequence must be 0.0 ";
41 s.add(5.0);
42 double p1 = predictor.get_new_prediction(&s);
43 ASSERT_LT(fabs(p1 - 5.0), epsilon) << "Prediction should be 5.0 but is "
44 << p1;
45 for (int i = 0; i < 40; i++) {
46 s.add(5.0);
47 }
48 double p2 = predictor.get_new_prediction(&s);
49
50 ASSERT_LT(fabs(p2 - 5.0), epsilon) << "Prediction should be 5.0 but is "
51 << p1;
52 }
53
54 TEST_VM(gc, testPredictionsAverageNotStdev) {
55 double const epsilon = 1e-6;
56 // The following tests checks that the initial predictions are based on
57 // the average of the sequence and not on the stddev (which is 0).
58 G1Predictions predictor(0.5);
59 TruncatedSeq s;
60
61 s.add(1.0);
62 double p1 = predictor.get_new_prediction(&s);
63
64 ASSERT_GT(p1, s.davg()) << "First prediction must be larger than average, "
65 << "but avg is " << s.davg() << " and prediction " << p1;
66 s.add(1.0);
67 double p2 = predictor.get_new_prediction(&s);
68 ASSERT_LT(p2, p1) << "First prediction must be larger than second, but "
69 << "they are " << p1 << " " << p2;
70 s.add(1.0);
71 double p3 = predictor.get_new_prediction(&s);
72
73 ASSERT_LT(p3, p2) << "Second prediction must be larger than third, "
74 << "but they are " << p2 << " " << p3;
75 s.add(1.0);
76 s.add(1.0); // Five elements are now in the sequence.
77 double p4 = predictor.get_new_prediction(&s);
78
79 ASSERT_LT(p4, p3) << "Fourth prediction must be smaller than third, "
80 << "but they are " << p3 << " " << p4;
81
82 ASSERT_LT(fabs(p4 - 1.0), epsilon) << "Prediction must be 1.0+epsilon, "
83 << "but is " << p4;
84 }
85
86 TEST_VM(gc, testPredictionsAverageStdev) {
87 double const epsilon = 1e-6;
88 // The following tests checks that initially prediction based on
89 // the average is used, that gets overridden by the stddev prediction at
90 // the end.
91 G1Predictions predictor(0.5);
92 TruncatedSeq s;
93
94 s.add(0.5);
95 double p1 = predictor.get_new_prediction(&s);
96 ASSERT_GT(p1, s.davg()) << "First prediction must be larger than average, but"
97 << " avg is " << s.davg() << " and prediction " << p1;
98 s.add(0.2);
99 double p2 = predictor.get_new_prediction(&s);
100 ASSERT_LT(p2, p1) << "First prediction must be larger than second, but "
101 << "they are " << p1 << " " << p2;
102 s.add(0.5);
103 double p3 = predictor.get_new_prediction(&s);
104
105 ASSERT_LT(p3, p2) << "Second prediction must be larger than third, but "
106 << "they are " << p2 << " " << p3;
107 s.add(0.2);
108 s.add(2.0);
109 double p4 = predictor.get_new_prediction(&s);
110
111 ASSERT_GT(p4, p3) << "Fourth prediction must be bigger than third, but "
112 << "they are " << p3 << " " << p4;
113 }
114
115 #endif