1 /*
   2  * Copyright (c) 2002, 2013, 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  *

  86 
  87   // Useful for modifying static structures after startup.
  88   void  modify(size_t avg, unsigned wt, bool force = false)  {
  89     assert(force, "Are you sure you want to call this?");
  90     _average = (float)avg;
  91     _weight  = wt;
  92   }
  93 
  94   // Accessors
  95   float    average() const       { return _average;       }
  96   unsigned weight()  const       { return _weight;        }
  97   unsigned count()   const       { return _sample_count;  }
  98   float    last_sample() const   { return _last_sample;   }
  99   bool     is_old()  const       { return _is_old;        }
 100 
 101   // Update data with a new sample.
 102   void sample(float new_sample);
 103 
 104   static inline float exp_avg(float avg, float sample,
 105                                unsigned int weight) {
 106     assert(0 <= weight && weight <= 100, "weight must be a percent");
 107     return (100.0F - weight) * avg / 100.0F + weight * sample / 100.0F;
 108   }
 109   static inline size_t exp_avg(size_t avg, size_t sample,
 110                                unsigned int weight) {
 111     // Convert to float and back to avoid integer overflow.
 112     return (size_t)exp_avg((float)avg, (float)sample, weight);
 113   }
 114 
 115   // Printing
 116   void print_on(outputStream* st) const;
 117   void print() const;
 118 };
 119 
 120 
 121 // A weighted average that includes a deviation from the average,
 122 // some multiple of which is added to the average.
 123 //
 124 // This serves as our best estimate of an upper bound on a future
 125 // unknown.
 126 class AdaptivePaddedAverage : public AdaptiveWeightedAverage {

   1 /*
   2  * Copyright (c) 2002, 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  *

  86 
  87   // Useful for modifying static structures after startup.
  88   void  modify(size_t avg, unsigned wt, bool force = false)  {
  89     assert(force, "Are you sure you want to call this?");
  90     _average = (float)avg;
  91     _weight  = wt;
  92   }
  93 
  94   // Accessors
  95   float    average() const       { return _average;       }
  96   unsigned weight()  const       { return _weight;        }
  97   unsigned count()   const       { return _sample_count;  }
  98   float    last_sample() const   { return _last_sample;   }
  99   bool     is_old()  const       { return _is_old;        }
 100 
 101   // Update data with a new sample.
 102   void sample(float new_sample);
 103 
 104   static inline float exp_avg(float avg, float sample,
 105                                unsigned int weight) {
 106     assert(weight <= 100, "weight must be a percent");
 107     return (100.0F - weight) * avg / 100.0F + weight * sample / 100.0F;
 108   }
 109   static inline size_t exp_avg(size_t avg, size_t sample,
 110                                unsigned int weight) {
 111     // Convert to float and back to avoid integer overflow.
 112     return (size_t)exp_avg((float)avg, (float)sample, weight);
 113   }
 114 
 115   // Printing
 116   void print_on(outputStream* st) const;
 117   void print() const;
 118 };
 119 
 120 
 121 // A weighted average that includes a deviation from the average,
 122 // some multiple of which is added to the average.
 123 //
 124 // This serves as our best estimate of an upper bound on a future
 125 // unknown.
 126 class AdaptivePaddedAverage : public AdaptiveWeightedAverage {