1 /*
   2  * Copyright (c) 1998, 2010, 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  *
  23  */
  24 
  25 #ifndef SHARE_VM_UTILITIES_HISTOGRAM_HPP
  26 #define SHARE_VM_UTILITIES_HISTOGRAM_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/os.hpp"
  30 #include "utilities/growableArray.hpp"
  31 #ifdef TARGET_OS_FAMILY_linux
  32 # include "os_linux.inline.hpp"
  33 #endif
  34 #ifdef TARGET_OS_FAMILY_solaris
  35 # include "os_solaris.inline.hpp"
  36 #endif
  37 #ifdef TARGET_OS_FAMILY_windows
  38 # include "os_windows.inline.hpp"
  39 #endif
  40 
  41 // This class provides a framework for collecting various statistics.
  42 // The current implementation is oriented towards counting invocations
  43 // of various types, but that can be easily changed.
  44 //
  45 // To use it, you need to declare a Histogram*, and a subtype of
  46 // HistogramElement:
  47 //
  48 //  HistogramElement* MyHistogram;
  49 //
  50 //  class MyHistogramElement : public HistogramElement {
  51 //    public:
  52 //      MyHistogramElement(char* name);
  53 //  };
  54 //
  55 //  MyHistogramElement::MyHistogramElement(char* elementName) {
  56 //    _name = elementName;
  57 //
  58 //    if(MyHistogram == NULL)
  59 //      MyHistogram = new Histogram("My Call Counts",100);
  60 //
  61 //    MyHistogram->add_element(this);
  62 //  }
  63 //
  64 //  #define MyCountWrapper(arg) static MyHistogramElement* e = new MyHistogramElement(arg); e->increment_count()
  65 //
  66 // This gives you a simple way to count invocations of specfic functions:
  67 //
  68 // void a_function_that_is_being_counted() {
  69 //   MyCountWrapper("FunctionName");
  70 //   ...
  71 // }
  72 //
  73 // To print the results, invoke print() on your Histogram*.
  74 
  75 #ifdef ASSERT
  76 
  77 class HistogramElement : public CHeapObj {
  78  protected:
  79   jint _count;
  80   const char* _name;
  81 
  82  public:
  83   HistogramElement();
  84   virtual int count();
  85   virtual const char* name();
  86   virtual void increment_count();
  87   void print_on(outputStream* st) const;
  88   virtual int compare(HistogramElement* e1,HistogramElement* e2);
  89 };
  90 
  91 class Histogram : public CHeapObj {
  92  protected:
  93   GrowableArray<HistogramElement*>* _elements;
  94   GrowableArray<HistogramElement*>* elements() { return _elements; }
  95   const char* _title;
  96   const char* title() { return _title; }
  97   static int sort_helper(HistogramElement** e1,HistogramElement** e2);
  98   virtual void print_header(outputStream* st);
  99   virtual void print_elements(outputStream* st);
 100 
 101  public:
 102   Histogram(const char* title,int estimatedSize);
 103   virtual void add_element(HistogramElement* element);
 104   void print_on(outputStream* st) const;
 105 };
 106 
 107 #endif
 108 
 109 #endif // SHARE_VM_UTILITIES_HISTOGRAM_HPP