jdk8-mips64-public/hotspot: src/share/vm/utilities/numberSeq.hpp@36c186bcc085 (annotated)

src/share/vm/utilities/numberSeq.hpp@36c186bcc085 (annotated)

src/share/vm/utilities/numberSeq.hpp

Mon, 03 Jan 2011 14:09:11 -0500

author: coleenp
date: Mon, 03 Jan 2011 14:09:11 -0500
changeset 2418: 36c186bcc085
parent 2314: f95d63e2154a
child 3641: 2c0751569716
permissions: -rw-r--r--

6302804: Hotspot VM dies ungraceful death when C heap is exhausted in various places.
Summary: enhance the error reporting mechanism to help user to fix the problem rather than making it look like a VM error.
Reviewed-by: kvn, kamg

 /*
  * 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/numberSeq.hpp@36c186bcc085 (annotated)

src/share/vm/utilities/numberSeq.hpp