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 25 #include "precompiled.hpp" 26 #include "gc/g1/g1Predictions.hpp" 27 #include "unittest.hpp" 28 29 static const double epsilon = 1e-6; 30 31 // Some basic formula tests with confidence = 0.0 32 TEST_VM(G1Predictions, basic_predictions) { 33 G1Predictions predictor(0.0); 34 TruncatedSeq s; 35 36 double p0 = predictor.get_new_prediction(&s); 37 ASSERT_LT(p0, epsilon) << "Initial prediction of empty sequence must be 0.0"; 38 39 s.add(5.0); 40 double p1 = predictor.get_new_prediction(&s); 41 ASSERT_NEAR(p1, 5.0, epsilon); 42 43 for (int i = 0; i < 40; i++) { 44 s.add(5.0); 45 } 46 double p2 = predictor.get_new_prediction(&s); 47 ASSERT_NEAR(p2, 5.0, epsilon); 48 } 49 50 // The following tests checks that the initial predictions are based on 51 // the average of the sequence and not on the stddev (which is 0). 52 TEST_VM(G1Predictions, average_not_stdev_predictions) { 53 G1Predictions predictor(0.5); 54 TruncatedSeq s; 55 56 s.add(1.0); 57 double p1 = predictor.get_new_prediction(&s); 58 ASSERT_GT(p1, s.davg()) << "First prediction must be greater than average"; 59 60 s.add(1.0); 61 double p2 = predictor.get_new_prediction(&s); 62 ASSERT_GT(p1, p2) << "First prediction must be greater than second"; 63 64 s.add(1.0); 65 double p3 = predictor.get_new_prediction(&s); 66 ASSERT_GT(p2, p3) << "Second prediction must be greater than third"; 67 68 s.add(1.0); 69 s.add(1.0); // Five elements are now in the sequence. 70 double p4 = predictor.get_new_prediction(&s); 71 ASSERT_LT(p4, p3) << "Fourth prediction must be smaller than third"; 72 ASSERT_NEAR(p4, 1.0, epsilon); 73 } 74 75 // The following tests checks that initially prediction based on 76 // the average is used, that gets overridden by the stddev prediction at 77 // the end. 78 TEST_VM(G1Predictions, average_stdev_predictions) { 79 G1Predictions predictor(0.5); 80 TruncatedSeq s; 81 82 s.add(0.5); 83 double p1 = predictor.get_new_prediction(&s); 84 ASSERT_GT(p1, s.davg()) << "First prediction must be greater than average"; 85 86 s.add(0.2); 87 double p2 = predictor.get_new_prediction(&s); 88 ASSERT_GT(p1, p2) << "First prediction must be greater than second"; 89 90 s.add(0.5); 91 double p3 = predictor.get_new_prediction(&s); 92 ASSERT_GT(p2, p3) << "Second prediction must be greater than third"; 93 94 s.add(0.2); 95 s.add(2.0); 96 double p4 = predictor.get_new_prediction(&s); 97 ASSERT_GT(p4, p3) << "Fourth prediction must be greater than third"; 98 }