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_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_klasses(NULL),
59 _subgraph_entry_fields(NULL) {}
60 ~KlassSubGraphInfo() {
61 if (_subgraph_klasses != NULL) {
62 delete _subgraph_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_klasses() {
72 return _subgraph_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_klass(Klass *orig_k, Klass *relocated_k);
79 };
80
81 // An archived record of object sub-graphs reachable from static
82 // fields within _k's mirror. The record is reloaded from the archive
83 // at runtime.
84 class ArchivedKlassSubGraphInfoRecord {
85 private:
86 ArchivedKlassSubGraphInfoRecord* _next;
87 Klass* _k;
88
89 // contains pairs of field offset and value for each subgraph entry field
90 Array<juint>* _entry_field_records;
91
92 // klasses of objects in archived sub-graphs referenced from the entry points
93 // (static fields) in the containing class
94 Array<Klass*>* _subgraph_klasses;
95 public:
96 ArchivedKlassSubGraphInfoRecord() :
97 _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_klasses(NULL) {}
98 void init(KlassSubGraphInfo* info);
99 Klass* klass() { return _k; }
100 ArchivedKlassSubGraphInfoRecord* next() { return _next; }
101 void set_next(ArchivedKlassSubGraphInfoRecord* next) { _next = next; }
102 Array<juint>* entry_field_records() { return _entry_field_records; }
103 Array<Klass*>* subgraph_klasses() { return _subgraph_klasses; }
104 };
105 #endif // INCLUDE_CDS_JAVA_HEAP
106
107 class HeapShared: AllStatic {
108 private:
109 #if INCLUDE_CDS_JAVA_HEAP
110 // This is a list of subgraph infos built at dump time while
111 // archiving object subgraphs.
112 static KlassSubGraphInfo* _subgraph_info_list;
113
114 // Contains a list of ArchivedKlassSubGraphInfoRecords that is stored
115 // in the archive file and reloaded at runtime.
116 static int _num_archived_subgraph_info_records;
117 static Array<ArchivedKlassSubGraphInfoRecord>* _archived_subgraph_info_records;
118
119 // Archive object sub-graph starting from the given static field
120 // in Klass k's mirror.
121 static void archive_reachable_objects_from_static_field(
122 InstanceKlass* k, const char* klass_name,
123 int field_ofset, const char* field_name, TRAPS);
124
125 static KlassSubGraphInfo* find_subgraph_info(Klass *k);
126 static KlassSubGraphInfo* get_subgraph_info(Klass *k);
127 static int num_of_subgraph_infos();
128
129 static size_t build_archived_subgraph_info_records(int num_records);
130
131 // Used by decode_with_archived_oop_encoding_mode
132 static address _narrow_oop_base;
133 static int _narrow_oop_shift;
134
135 static bool oop_equals(oop const& p1, oop const& p2) {
136 return primitive_equals<oop>(p1, p2);
137 }
138
139 static unsigned oop_hash(oop const& p) {
140 return primitive_hash<address>((address)p);
141 }
142
143 typedef ResourceHashtable<oop, bool,
144 HeapShared::oop_hash,
145 HeapShared::oop_equals,
146 15889, // prime number
147 ResourceObj::C_HEAP> SeenObjectsTable;
148
149 static SeenObjectsTable *_seen_objects_table;
150
151 static void record_subgraph_klasses();
152 static void start_recording_subgraph_klasses(InstanceKlass *k, const char* klass_name);
153 static void record_subgraph_klasses_from_static_field(InstanceKlass *k,
154 const char* klass_name,
155 int field_offset,
156 const char* field_name);
157 static void done_recording_subgraph_klasses(InstanceKlass *k);
158
159 #endif // INCLUDE_CDS_JAVA_HEAP
160 public:
161 static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);
162 static void write_archived_subgraph_infos() NOT_CDS_JAVA_HEAP_RETURN;
163 static void initialize_from_archived_subgraph(Klass* k) NOT_CDS_JAVA_HEAP_RETURN;
164
165 // NarrowOops stored in the CDS archive may use a different encoding scheme
166 // than Universe::narrow_oop_{base,shift} -- see FileMapInfo::map_heap_regions_impl.
167 // To decode them, do not use CompressedOops::decode_not_null. Use this
168 // function instead.
169 inline static oop decode_with_archived_oop_encoding_mode(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
170
171 static void init_narrow_oop_decoding(address base, int shift) NOT_CDS_JAVA_HEAP_RETURN;
172
173 static void patch_archived_heap_embedded_pointers(MemRegion mem, address oopmap,
174 size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
175
176 static void init_archivable_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
177 static void archive_module_graph_objects(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
178
179 #if INCLUDE_CDS_JAVA_HEAP
180 static ResourceBitMap calculate_oopmap(MemRegion region);
181 static bool has_been_seen_during_subgraph_klasses_recording(oop obj);
182 static void record_subgraph_klasses_for(KlassSubGraphInfo* subgraph_info, oop obj);
183 #endif
184 };
185 #endif // SHARE_VM_MEMORY_HEAPSHARED_HPP