Mercurial > hg > truffle
diff 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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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/utilities/numberSeq.hpp Thu Jun 05 15:57:56 2008 -0700 @@ -0,0 +1,117 @@ +/* + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +/** + ** This file contains a few classes that represent number sequence, + ** x1, x2, x3, ..., xN, and can calculate their avg, max, and sd. + ** + ** Here's a quick description of the classes: + ** + ** AbsSeq: abstract superclass + ** NumberSeq: the sequence is assumed to be very long and the + ** maximum, avg, sd, davg, and dsd are calculated over all its elements + ** TruncatedSeq: this class keeps track of the last L elements + ** of the sequence and calculates avg, max, and sd only over them + **/ + +#define DEFAULT_ALPHA_VALUE 0.7 + +class AbsSeq { +private: + void init(double alpha); + +protected: + int _num; // the number of elements in the sequence + double _sum; // the sum of the elements in the sequence + double _sum_of_squares; // the sum of squares of the elements in the sequence + + double _davg; // decaying average + double _dvariance; // decaying variance + double _alpha; // factor for the decaying average / variance + + // This is what we divide with to get the average. In a standard + // number sequence, this should just be the number of elements in it. + virtual double total() const { return (double) _num; }; + +public: + AbsSeq(double alpha = DEFAULT_ALPHA_VALUE); + + virtual void add(double val); // adds a new element to the sequence + void add(unsigned val) { add((double) val); } + virtual double maximum() const = 0; // maximum element in the sequence + virtual double last() const = 0; // last element added in the sequence + + // the number of elements in the sequence + int num() const { return _num; } + // the sum of the elements in the sequence + double sum() const { return _sum; } + + double avg() const; // the average of the sequence + double variance() const; // the variance of the sequence + double sd() const; // the standard deviation of the sequence + + double davg() const; // decaying average + double dvariance() const; // decaying variance + double dsd() const; // decaying "standard deviation" +}; + +class NumberSeq: public AbsSeq { +private: + bool check_nums(NumberSeq* total, int n, NumberSeq** parts); + +protected: + double _last; + double _maximum; // keep track of maximum value + +public: + NumberSeq(double alpha = DEFAULT_ALPHA_VALUE); + NumberSeq(NumberSeq* total, int n_parts, NumberSeq** parts); + + virtual void add(double val); + virtual double maximum() const { return _maximum; } + virtual double last() const { return _last; } +}; + +class TruncatedSeq: public AbsSeq { +private: + enum PrivateConstants { + DefaultSeqLength = 10 + }; + void init(); +protected: + double *_sequence; // buffers the last L elements in the sequence + int _length; // this is L + int _next; // oldest slot in the array, i.e. next to be overwritten + +public: + // accepts a value for L + TruncatedSeq(int length = DefaultSeqLength, + double alpha = DEFAULT_ALPHA_VALUE); + virtual void add(double val); + virtual double maximum() const; + virtual double last() const; // the last value added to the sequence + + double oldest() const; // the oldest valid value in the sequence + double predict_next() const; // prediction based on linear regression +};