Mercurial > hg > truffle
comparison src/share/vm/utilities/numberSeq.hpp @ 342:37f87013dfd8
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author | ysr |
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date | Thu, 05 Jun 2008 15:57:56 -0700 |
parents | |
children | 89f1b9ae8991 |
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1 /* | |
2 * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 /** | |
26 ** This file contains a few classes that represent number sequence, | |
27 ** x1, x2, x3, ..., xN, and can calculate their avg, max, and sd. | |
28 ** | |
29 ** Here's a quick description of the classes: | |
30 ** | |
31 ** AbsSeq: abstract superclass | |
32 ** NumberSeq: the sequence is assumed to be very long and the | |
33 ** maximum, avg, sd, davg, and dsd are calculated over all its elements | |
34 ** TruncatedSeq: this class keeps track of the last L elements | |
35 ** of the sequence and calculates avg, max, and sd only over them | |
36 **/ | |
37 | |
38 #define DEFAULT_ALPHA_VALUE 0.7 | |
39 | |
40 class AbsSeq { | |
41 private: | |
42 void init(double alpha); | |
43 | |
44 protected: | |
45 int _num; // the number of elements in the sequence | |
46 double _sum; // the sum of the elements in the sequence | |
47 double _sum_of_squares; // the sum of squares of the elements in the sequence | |
48 | |
49 double _davg; // decaying average | |
50 double _dvariance; // decaying variance | |
51 double _alpha; // factor for the decaying average / variance | |
52 | |
53 // This is what we divide with to get the average. In a standard | |
54 // number sequence, this should just be the number of elements in it. | |
55 virtual double total() const { return (double) _num; }; | |
56 | |
57 public: | |
58 AbsSeq(double alpha = DEFAULT_ALPHA_VALUE); | |
59 | |
60 virtual void add(double val); // adds a new element to the sequence | |
61 void add(unsigned val) { add((double) val); } | |
62 virtual double maximum() const = 0; // maximum element in the sequence | |
63 virtual double last() const = 0; // last element added in the sequence | |
64 | |
65 // the number of elements in the sequence | |
66 int num() const { return _num; } | |
67 // the sum of the elements in the sequence | |
68 double sum() const { return _sum; } | |
69 | |
70 double avg() const; // the average of the sequence | |
71 double variance() const; // the variance of the sequence | |
72 double sd() const; // the standard deviation of the sequence | |
73 | |
74 double davg() const; // decaying average | |
75 double dvariance() const; // decaying variance | |
76 double dsd() const; // decaying "standard deviation" | |
77 }; | |
78 | |
79 class NumberSeq: public AbsSeq { | |
80 private: | |
81 bool check_nums(NumberSeq* total, int n, NumberSeq** parts); | |
82 | |
83 protected: | |
84 double _last; | |
85 double _maximum; // keep track of maximum value | |
86 | |
87 public: | |
88 NumberSeq(double alpha = DEFAULT_ALPHA_VALUE); | |
89 NumberSeq(NumberSeq* total, int n_parts, NumberSeq** parts); | |
90 | |
91 virtual void add(double val); | |
92 virtual double maximum() const { return _maximum; } | |
93 virtual double last() const { return _last; } | |
94 }; | |
95 | |
96 class TruncatedSeq: public AbsSeq { | |
97 private: | |
98 enum PrivateConstants { | |
99 DefaultSeqLength = 10 | |
100 }; | |
101 void init(); | |
102 protected: | |
103 double *_sequence; // buffers the last L elements in the sequence | |
104 int _length; // this is L | |
105 int _next; // oldest slot in the array, i.e. next to be overwritten | |
106 | |
107 public: | |
108 // accepts a value for L | |
109 TruncatedSeq(int length = DefaultSeqLength, | |
110 double alpha = DEFAULT_ALPHA_VALUE); | |
111 virtual void add(double val); | |
112 virtual double maximum() const; | |
113 virtual double last() const; // the last value added to the sequence | |
114 | |
115 double oldest() const; // the oldest valid value in the sequence | |
116 double predict_next() const; // prediction based on linear regression | |
117 }; |