histogram.hpp revision 2721:f08d439fab8c 
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.
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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.
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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#ifdef TARGET_OS_FAMILY_bsd
41# include "os_bsd.inline.hpp"
42#endif
43
44// This class provides a framework for collecting various statistics.
45// The current implementation is oriented towards counting invocations
46// of various types, but that can be easily changed.
47//
48// To use it, you need to declare a Histogram*, and a subtype of
49// HistogramElement:
50//
51//  HistogramElement* MyHistogram;
52//
53//  class MyHistogramElement : public HistogramElement {
54//    public:
55//      MyHistogramElement(char* name);
56//  };
57//
58//  MyHistogramElement::MyHistogramElement(char* elementName) {
59//    _name = elementName;
60//
61//    if(MyHistogram == NULL)
62//      MyHistogram = new Histogram("My Call Counts",100);
63//
64//    MyHistogram->add_element(this);
65//  }
66//
67//  #define MyCountWrapper(arg) static MyHistogramElement* e = new MyHistogramElement(arg); e->increment_count()
68//
69// This gives you a simple way to count invocations of specfic functions:
70//
71// void a_function_that_is_being_counted() {
72//   MyCountWrapper("FunctionName");
73//   ...
74// }
75//
76// To print the results, invoke print() on your Histogram*.
77
78#ifdef ASSERT
79
80class HistogramElement : public CHeapObj {
81 protected:
82  jint _count;
83  const char* _name;
84
85 public:
86  HistogramElement();
87  virtual int count();
88  virtual const char* name();
89  virtual void increment_count();
90  void print_on(outputStream* st) const;
91  virtual int compare(HistogramElement* e1,HistogramElement* e2);
92};
93
94class Histogram : public CHeapObj {
95 protected:
96  GrowableArray<HistogramElement*>* _elements;
97  GrowableArray<HistogramElement*>* elements() { return _elements; }
98  const char* _title;
99  const char* title() { return _title; }
100  static int sort_helper(HistogramElement** e1,HistogramElement** e2);
101  virtual void print_header(outputStream* st);
102  virtual void print_elements(outputStream* st);
103
104 public:
105  Histogram(const char* title,int estimatedSize);
106  virtual void add_element(HistogramElement* element);
107  void print_on(outputStream* st) const;
108};
109
110#endif
111
112#endif // SHARE_VM_UTILITIES_HISTOGRAM_HPP
113