1 /*
   2  * Copyright (c) 2002, 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_MEMORY_HEAPINSPECTION_HPP
  26 #define SHARE_VM_MEMORY_HEAPINSPECTION_HPP
  27 
  28 #include "memory/allocation.inline.hpp"
  29 #include "oops/oop.inline.hpp"
  30 
  31 #if INCLUDE_SERVICES
  32 
  33 
  34 // HeapInspection
  35 
  36 // KlassInfoTable is a bucket hash table that
  37 // maps Klass*s to extra information:
  38 //    instance count and instance word size.
  39 //
  40 // A KlassInfoBucket is the head of a link list
  41 // of KlassInfoEntry's
  42 //
  43 // KlassInfoHisto is a growable array of pointers
  44 // to KlassInfoEntry's and is used to sort
  45 // the entries.
  46 
  47 class KlassInfoEntry: public CHeapObj<mtInternal> {
  48  private:
  49   KlassInfoEntry* _next;
  50   Klass*          _klass;
  51   long            _instance_count;
  52   size_t          _instance_words;
  53 
  54  public:
  55   KlassInfoEntry(Klass* k, KlassInfoEntry* next) :
  56     _klass(k), _instance_count(0), _instance_words(0), _next(next)
  57   {}
  58   KlassInfoEntry* next()     { return _next; }
  59   bool is_equal(Klass* k)  { return k == _klass; }
  60   Klass* klass()           { return _klass; }
  61   long count()               { return _instance_count; }
  62   void set_count(long ct)    { _instance_count = ct; }
  63   size_t words()             { return _instance_words; }
  64   void set_words(size_t wds) { _instance_words = wds; }
  65   int compare(KlassInfoEntry* e1, KlassInfoEntry* e2);
  66   void print_on(outputStream* st) const;
  67 };
  68 
  69 class KlassInfoClosure: public StackObj {
  70  public:
  71   // Called for each KlassInfoEntry.
  72   virtual void do_cinfo(KlassInfoEntry* cie) = 0;
  73 };
  74 
  75 class KlassInfoBucket: public CHeapObj<mtInternal> {
  76  private:
  77   KlassInfoEntry* _list;
  78   KlassInfoEntry* list()           { return _list; }
  79   void set_list(KlassInfoEntry* l) { _list = l; }
  80  public:
  81   KlassInfoEntry* lookup(Klass* const k);
  82   void initialize() { _list = NULL; }
  83   void empty();
  84   void iterate(KlassInfoClosure* cic);
  85 };
  86 
  87 class KlassInfoTable: public StackObj {
  88  private:
  89   int _size;
  90 
  91   // An aligned reference address (typically the least
  92   // address in the perm gen) used for hashing klass
  93   // objects.
  94   HeapWord* _ref;
  95 
  96   KlassInfoBucket* _buckets;
  97   uint hash(Klass* p);
  98   KlassInfoEntry* lookup(Klass* const k);
  99 
 100  public:
 101   // Table size
 102   enum {
 103     cit_size = 20011
 104   };
 105   KlassInfoTable(int size, HeapWord* ref);
 106   ~KlassInfoTable();
 107   bool record_instance(const oop obj);
 108   void iterate(KlassInfoClosure* cic);
 109   bool allocation_failed() { return _buckets == NULL; }
 110 };
 111 
 112 class KlassInfoHisto : public StackObj {
 113  private:
 114   GrowableArray<KlassInfoEntry*>* _elements;
 115   GrowableArray<KlassInfoEntry*>* elements() const { return _elements; }
 116   const char* _title;
 117   const char* title() const { return _title; }
 118   static int sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2);
 119   void print_elements(outputStream* st) const;
 120  public:
 121   enum {
 122     histo_initial_size = 1000
 123   };
 124   KlassInfoHisto(const char* title,
 125              int estimatedCount);
 126   ~KlassInfoHisto();
 127   void add(KlassInfoEntry* cie);
 128   void print_on(outputStream* st) const;
 129   void sort();
 130 };
 131 
 132 #endif // INCLUDE_SERVICES
 133 
 134 class HeapInspection : public AllStatic {
 135  public:
 136   static void heap_inspection(outputStream* st, bool need_prologue) NOT_SERVICES_RETURN;
 137   static void find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) NOT_SERVICES_RETURN;
 138 };
 139 
 140 #endif // SHARE_VM_MEMORY_HEAPINSPECTION_HPP