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 "gc/g1/g1Predictions.hpp" 26 #include "unittest.hpp" 27 28 static const double epsilon = 1e-6; 29 30 // Some basic formula tests with confidence = 0.0 31 TEST_VM(G1Predictions, basic_predictions) { 32 G1Predictions predictor(0.0); 33 TruncatedSeq s; 34 35 double p0 = predictor.get_new_prediction(&s); 36 ASSERT_LT(p0, epsilon) << "Initial prediction of empty sequence must be 0.0"; 37 38 s.add(5.0); 39 double p1 = predictor.get_new_prediction(&s); 40 ASSERT_NEAR(p1, 5.0, epsilon); 41 42 for (int i = 0; i < 40; i++) { 43 s.add(5.0); 44 } 45 double p2 = predictor.get_new_prediction(&s); 46 ASSERT_NEAR(p2, 5.0, epsilon); 47 } 48 49 // The following tests checks that the initial predictions are based on 50 // the average of the sequence and not on the stddev (which is 0). 51 TEST_VM(G1Predictions, average_not_stdev_predictions) { 52 G1Predictions predictor(0.5); 53 TruncatedSeq s; 54 55 s.add(1.0); 56 double p1 = predictor.get_new_prediction(&s); 57 ASSERT_GT(p1, s.davg()) << "First prediction must be larger than average"; 58 59 s.add(1.0); 60 double p2 = predictor.get_new_prediction(&s); 61 ASSERT_GT(p1, p2) << "First prediction must be larger than second"; 62 63 s.add(1.0); 64 double p3 = predictor.get_new_prediction(&s); 65 ASSERT_GT(p2, p3) << "Second prediction must be larger than third"; 66 67 s.add(1.0); 68 s.add(1.0); // Five elements are now in the sequence. 69 double p4 = predictor.get_new_prediction(&s); 70 ASSERT_LT(p4, p3) << "Fourth prediction must be smaller than third"; 71 ASSERT_NEAR(p4, 1.0, epsilon); 72 } 73 74 // The following tests checks that initially prediction based on 75 // the average is used, that gets overridden by the stddev prediction at 76 // the end. 77 TEST_VM(G1Predictions, average_stdev_predictions) { 78 G1Predictions predictor(0.5); 79 TruncatedSeq s; 80 81 s.add(0.5); 82 double p1 = predictor.get_new_prediction(&s); 83 ASSERT_GT(p1, s.davg()) << "First prediction must be larger than average"; 84 85 s.add(0.2); 86 double p2 = predictor.get_new_prediction(&s); 87 ASSERT_GT(p1, p2) << "First prediction must be larger than second"; 88 89 s.add(0.5); 90 double p3 = predictor.get_new_prediction(&s); 91 ASSERT_GT(p2, p3) << "Second prediction must be larger than third"; 92 93 s.add(0.2); 94 s.add(2.0); 95 double p4 = predictor.get_new_prediction(&s); 96 ASSERT_GT(p4, p3) << "Fourth prediction must be larger than third"; 97 }