1 /*
2 * Copyright (c) 2018, 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_HEAPSHARED_HPP
26 #define SHARE_VM_MEMORY_HEAPSHARED_HPP
27
28 #include "classfile/systemDictionary.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/universe.hpp"
31 #include "oops/objArrayKlass.hpp"
32 #include "oops/oop.hpp"
33 #include "oops/typeArrayKlass.hpp"
34 #include "utilities/bitMap.hpp"
35 #include "utilities/growableArray.hpp"
36 #include "utilities/resourceHash.hpp"
37
38 #if INCLUDE_CDS_JAVA_HEAP
39 // A dump time sub-graph info for Klass _k. It includes the entry points
40 // (static fields in _k's mirror) of the archived sub-graphs reachable
41 // from _k's mirror. It also contains a list of Klasses of the objects
42 // within the sub-graphs.
43 class KlassSubGraphInfo: public CHeapObj<mtClass> {
44 private:
45 KlassSubGraphInfo* _next;
46 // The class that contains the static field(s) as the entry point(s)
47 // of archived object sub-graph(s).
48 Klass* _k;
49 // A list of classes need to be loaded and initialized before the archived
50 // object sub-graphs can be accessed at runtime.
51 GrowableArray<Klass*>* _subgraph_object_klasses;
52 // A list of _k's static fields as the entry points of archived sub-graphs.
53 // For each entry field, it is a pair of field_offset and field_value.
54 GrowableArray<juint>* _subgraph_entry_fields;
55
56 public:
57 KlassSubGraphInfo(Klass* k, KlassSubGraphInfo* next) :
58 _next(next), _k(k), _subgraph_object_klasses(NULL),
59 _subgraph_entry_fields(NULL) {}
60 ~KlassSubGraphInfo() {
61 if (_subgraph_object_klasses != NULL) {
62 delete _subgraph_object_klasses;
63 }
64 if (_subgraph_entry_fields != NULL) {
65 delete _subgraph_entry_fields;
66 }
67 };
68
69 KlassSubGraphInfo* next() { return _next; }
70 Klass* klass() { return _k; }
71 GrowableArray<Klass*>* subgraph_object_klasses() {
72 return _subgraph_object_klasses;
73 }
74 GrowableArray<juint>* subgraph_entry_fields() {
75 return _subgraph_entry_fields;
76 }
77 void add_subgraph_entry_field(int static_field_offset, oop v);
78 void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);
79 int num_subgraph_object_klasses() {
80 return _subgraph_object_klasses == NULL ? 0 :
81 _subgraph_object_klasses->length();
82 }
83 };
84
85 // An archived record of object sub-graphs reachable from static
86 // fields within _k's mirror. The record is reloaded from the archive
87 // at runtime.
88 class ArchivedKlassSubGraphInfoRecord {
89 private:
90 ArchivedKlassSubGraphInfoRecord* _next;
91 Klass* _k;
92
93 // contains pairs of field offset and value for each subgraph entry field
94 Array<juint>* _entry_field_records;
95
96 // klasses of objects in archived sub-graphs referenced from the entry points
97 // (static fields) in the containing class
98 Array<Klass*>* _subgraph_object_klasses;
99 public:
100 ArchivedKlassSubGraphInfoRecord() :
101 _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_object_klasses(NULL) {}
102 void init(KlassSubGraphInfo* info);
103 Klass* klass() { return _k; }
104 ArchivedKlassSubGraphInfoRecord* next() { return _next; }
105 void set_next(ArchivedKlassSubGraphInfoRecord* next) { _next = next; }
106 Array<juint>* entry_field_records() { return _entry_field_records; }
107 Array<Klass*>* subgraph_object_klasses() { return _subgraph_object_klasses; }
108 };
109 #endif // INCLUDE_CDS_JAVA_HEAP
110
111 class HeapShared: AllStatic {
112 friend class VerifySharedOopClosure;
113 private:
114 #if INCLUDE_CDS_JAVA_HEAP
115 // This is a list of subgraph infos built at dump time while
116 // archiving object subgraphs.
117 static KlassSubGraphInfo* _subgraph_info_list;
118
119 // Contains a list of ArchivedKlassSubGraphInfoRecords that is stored
120 // in the archive file and reloaded at runtime.
121 static int _num_archived_subgraph_info_records;
122 static Array<ArchivedKlassSubGraphInfoRecord>* _archived_subgraph_info_records;
123
124 // Archive object sub-graph starting from the given static field
125 // in Klass k's mirror.
126 static void archive_reachable_objects_from_static_field(
127 InstanceKlass* k, const char* klass_name,
128 int field_offset, const char* field_name, TRAPS);
129 static void verify_subgraph_from_static_field(
130 InstanceKlass* k, int field_offset) PRODUCT_RETURN;
131
132 static void verify_reachable_objects_from(oop obj, bool is_archived) PRODUCT_RETURN;
133
134 static KlassSubGraphInfo* find_subgraph_info(Klass *k);
135 static KlassSubGraphInfo* get_subgraph_info(Klass *k);
136 static int num_of_subgraph_infos();
137
138 static size_t build_archived_subgraph_info_records(int num_records);
139
140 // Used by decode_from_archive
141 static address _narrow_oop_base;
142 static int _narrow_oop_shift;
143
144 static bool oop_equals(oop const& p1, oop const& p2) {
145 return primitive_equals<oop>(p1, p2);
146 }
147
148 static unsigned oop_hash(oop const& p) {
149 return primitive_hash<address>((address)p);
150 }
151
152 typedef ResourceHashtable<oop, bool,
153 HeapShared::oop_hash,
154 HeapShared::oop_equals,
155 15889, // prime number
156 ResourceObj::C_HEAP> SeenObjectsTable;
157
158 static SeenObjectsTable *_seen_objects_table;
159
160 static void init_seen_objects_table() {
161 assert(_seen_objects_table == NULL, "must be");
162 _seen_objects_table = new (ResourceObj::C_HEAP, mtClass)SeenObjectsTable();
163 }
164 static void delete_seen_objects_table() {
165 assert(_seen_objects_table != NULL, "must be");
166 delete _seen_objects_table;
167 _seen_objects_table = NULL;
168 }
169
170 // Statistics (for one round of start_recording_subgraph ... done_recording_subgraph)
171 static int _num_new_walked_objs;
172 static int _num_new_archived_objs;
173 static int _num_old_recorded_klasses;
174
175 // Statistics (for all archived subgraphs)
176 static int _num_total_subgraph_recordings;
177 static int _num_total_walked_objs;
178 static int _num_total_archived_objs;
179 static int _num_total_recorded_klasses;
180 static int _num_total_verifications;
181
182 static void start_recording_subgraph(InstanceKlass *k, const char* klass_name);
183 static void done_recording_subgraph(InstanceKlass *k, const char* klass_name);
184
185 static bool has_been_seen_during_subgraph_recording(oop obj);
186 static void set_has_been_seen_during_subgraph_recording(oop obj);
187 #endif // INCLUDE_CDS_JAVA_HEAP
188 public:
189 static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);
190 static void write_archived_subgraph_infos() NOT_CDS_JAVA_HEAP_RETURN;
191 static void initialize_from_archived_subgraph(Klass* k) NOT_CDS_JAVA_HEAP_RETURN;
192
193 // NarrowOops stored in the CDS archive may use a different encoding scheme
194 // than Universe::narrow_oop_{base,shift} -- see FileMapInfo::map_heap_regions_impl.
195 // To decode them, do not use CompressedOops::decode_not_null. Use this
196 // function instead.
197 inline static oop decode_from_archive(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
198
199 static void init_narrow_oop_decoding(address base, int shift) NOT_CDS_JAVA_HEAP_RETURN;
200
201 static void patch_archived_heap_embedded_pointers(MemRegion mem, address oopmap,
202 size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
203
204 static void init_archivable_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
205 static void archive_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
206
207 #if INCLUDE_CDS_JAVA_HEAP
208 static ResourceBitMap calculate_oopmap(MemRegion region);
209 static oop archive_reachable_objects_from(int level, KlassSubGraphInfo* subgraph_info, oop orig_obj, TRAPS);
210 static void verify_subgraph_from(oop orig_obj) PRODUCT_RETURN;
211 #endif
212 };
213 #endif // SHARE_VM_MEMORY_HEAPSHARED_HPP