1 /*

     2  * Copyright (c) 2015, 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 

    28 #ifndef PRODUCT

    29 

    30 void G1Predictions::test() {

    31   double const epsilon = 1e-6;

    32   {

    33     // Some basic formula tests with confidence = 0.0

    34     G1Predictions predictor(0.0);

    35     TruncatedSeq s;

    36 

    37     double p0 = predictor.get_new_prediction(&s);

    38     assert(p0 < epsilon, "Initial prediction of empty sequence must be 0.0 but is %f", p0);

    39 

    40     s.add(5.0);

    41     double p1 = predictor.get_new_prediction(&s);

    42     assert(fabs(p1 - 5.0) < epsilon, "Prediction should be 5.0 but is %f", p1);

    43     for (int i = 0; i < 40; i++) {

    44       s.add(5.0);

    45     }

    46     double p2 = predictor.get_new_prediction(&s);

    47     assert(fabs(p2 - 5.0) < epsilon, "Prediction should be 5.0 but is %f", p1);

    48   }

    49 

    50   {

    51     // The following tests checks that the initial predictions are based on the

    52     // average of the sequence and not on the stddev (which is 0).

    53     G1Predictions predictor(0.5);

    54     TruncatedSeq s;

    55 

    56     s.add(1.0);

    57     double p1 = predictor.get_new_prediction(&s);

    58     assert(p1 > 1.0, "First prediction must be larger than average, but avg is %f and prediction %f", s.davg(), p1);

    59     s.add(1.0);

    60     double p2 = predictor.get_new_prediction(&s);

    61     assert(p2 < p1, "First prediction must be larger than second, but they are %f %f", p1, p2);

    62     s.add(1.0);

    63     double p3 = predictor.get_new_prediction(&s);

    64     assert(p3 < p2, "Second prediction must be larger than third, but they are %f %f", p2, p3);

    65     s.add(1.0);

    66     s.add(1.0); // Five elements are now in the sequence.

    67     double p5 = predictor.get_new_prediction(&s);

    68     assert(p5 < p3, "Fifth prediction must be smaller than third, but they are %f %f", p3, p5);

    69     assert(fabs(p5 - 1.0) < epsilon, "Prediction must be 1.0+epsilon, but is %f", p5);

    70   }

    71 

    72   {

    73     // The following tests checks that initially prediction based on the average is

    74     // used, that gets overridden by the stddev prediction at the end.

    75     G1Predictions predictor(0.5);

    76     TruncatedSeq s;

    77 

    78     s.add(0.5);

    79     double p1 = predictor.get_new_prediction(&s);

    80     assert(p1 > 0.5, "First prediction must be larger than average, but avg is %f and prediction %f", s.davg(), p1);

    81     s.add(0.2);

    82     double p2 = predictor.get_new_prediction(&s);

    83     assert(p2 < p1, "First prediction must be larger than second, but they are %f %f", p1, p2);

    84     s.add(0.5);

    85     double p3 = predictor.get_new_prediction(&s);

    86     assert(p3 < p2, "Second prediction must be larger than third, but they are %f %f", p2, p3);

    87     s.add(0.2);

    88     s.add(2.0);

    89     double p5 = predictor.get_new_prediction(&s);

    90     assert(p5 > p3, "Fifth prediction must be bigger than third, but they are %f %f", p3, p5);

    91   }

    92 }

    93 

    94 void TestPredictions_test() {

    95   G1Predictions::test();

    96 }

    97 

    98 #endif