Mercurial > hg > graal-compiler
view src/share/vm/utilities/numberSeq.hpp @ 2149:7e37af9d69ef
7011379: G1: overly long concurrent marking cycles
Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr
author | tonyp |
---|---|
date | Wed, 19 Jan 2011 09:35:17 -0500 |
parents | f95d63e2154a |
children | 2c0751569716 |
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/* * Copyright (c) 2001, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_UTILITIES_NUMBERSEQ_HPP #define SHARE_VM_UTILITIES_NUMBERSEQ_HPP /** ** 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" // Debugging/Printing virtual void dump(); virtual void dump_on(outputStream* s); }; 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; } // Debugging/Printing virtual void dump_on(outputStream* s); }; 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 // Debugging/Printing virtual void dump_on(outputStream* s); }; #endif // SHARE_VM_UTILITIES_NUMBERSEQ_HPP