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