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/universe.hpp"
30 #include "oops/objArrayKlass.hpp"
31 #include "oops/oop.hpp"
32 #include "oops/typeArrayKlass.hpp"
33 #include "utilities/bitMap.hpp"
34 #include "utilities/growableArray.hpp"
35
36 #if INCLUDE_CDS_JAVA_HEAP
37 // A dump time sub-graph info for Klass _k. It includes the entry points
38 // (static fields in _k's mirror) of the archived sub-graphs reachable
39 // from _k's mirror. It also contains a list of Klasses of the objects
40 // within the sub-graphs.
41 class KlassSubGraphInfo: public CHeapObj<mtClass> {
42 private:
43 KlassSubGraphInfo* _next;
44 // The class that contains the static field(s) as the entry point(s)
45 // of archived object sub-graph(s).
46 Klass* _k;
47 // A list of classes need to be loaded and initialized before the archived
48 // object sub-graphs can be accessed at runtime.
49 GrowableArray<Klass*>* _subgraph_object_klasses;
50 // A list of _k's static fields as the entry points of archived sub-graphs.
51 // For each entry field, it is a pair of field_offset and field_value.
52 GrowableArray<juint>* _subgraph_entry_fields;
53
54 public:
55 KlassSubGraphInfo(Klass* k, KlassSubGraphInfo* next) :
56 _next(next), _k(k), _subgraph_object_klasses(NULL),
57 _subgraph_entry_fields(NULL) {}
58 ~KlassSubGraphInfo() {
59 if (_subgraph_object_klasses != NULL) {
60 delete _subgraph_object_klasses;
61 }
62 if (_subgraph_entry_fields != NULL) {
63 delete _subgraph_entry_fields;
64 }
65 };
66
67 KlassSubGraphInfo* next() { return _next; }
68 Klass* klass() { return _k; }
69 GrowableArray<Klass*>* subgraph_object_klasses() {
70 return _subgraph_object_klasses;
71 }
72 GrowableArray<juint>* subgraph_entry_fields() {
73 return _subgraph_entry_fields;
74 }
75 void add_subgraph_entry_field(int static_field_offset, oop v);
76 void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);
77 };
78
79 // An archived record of object sub-graphs reachable from static
80 // fields within _k's mirror. The record is reloaded from the archive
81 // at runtime.
82 class ArchivedKlassSubGraphInfoRecord {
83 private:
84 ArchivedKlassSubGraphInfoRecord* _next;
85 Klass* _k;
86
87 // contains pairs of field offset and value for each subgraph entry field
88 Array<juint>* _entry_field_records;
89
90 // klasses of objects in archived sub-graphs referenced from the entry points
91 // (static fields) in the containing class
92 Array<Klass*>* _subgraph_klasses;
93 public:
94 ArchivedKlassSubGraphInfoRecord() :
95 _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_klasses(NULL) {}
96 void init(KlassSubGraphInfo* info);
97 Klass* klass() { return _k; }
98 ArchivedKlassSubGraphInfoRecord* next() { return _next; }
99 void set_next(ArchivedKlassSubGraphInfoRecord* next) { _next = next; }
100 Array<juint>* entry_field_records() { return _entry_field_records; }
101 Array<Klass*>* subgraph_klasses() { return _subgraph_klasses; }
102 };
103 #endif // INCLUDE_CDS_JAVA_HEAP
104
105 class HeapShared: AllStatic {
106 private:
107 #if INCLUDE_CDS_JAVA_HEAP
108 // This is a list of subgraph infos built at dump time while
109 // archiving object subgraphs.
110 static KlassSubGraphInfo* _subgraph_info_list;
111
112 // Contains a list of ArchivedKlassSubGraphInfoRecords that is stored
113 // in the archive file and reloaded at runtime.
114 static int _num_archived_subgraph_info_records;
115 static Array<ArchivedKlassSubGraphInfoRecord>* _archived_subgraph_info_records;
116
117 // Archive object sub-graph starting from the given static field
118 // in Klass k's mirror.
119 static void archive_reachable_objects_from_static_field(
120 Klass* k, int field_ofset, BasicType field_type, TRAPS);
121
122 static KlassSubGraphInfo* find_subgraph_info(Klass *k);
123 static KlassSubGraphInfo* get_subgraph_info(Klass *k);
124 static int num_of_subgraph_infos();
125
126 static size_t build_archived_subgraph_info_records(int num_records);
127
128 // Used by decode_with_archived_oop_encoding_mode
129 static address _narrow_oop_base;
130 static int _narrow_oop_shift;
131
132 #endif // INCLUDE_CDS_JAVA_HEAP
133 public:
134 static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);
135 static void write_archived_subgraph_infos() NOT_CDS_JAVA_HEAP_RETURN;
136 static void initialize_from_archived_subgraph(Klass* k) NOT_CDS_JAVA_HEAP_RETURN;
137
138 // NarrowOops stored in the CDS archive may use a different encoding scheme
139 // than Universe::narrow_oop_{base,shift} -- see FileMapInfo::map_heap_regions_impl.
140 // To decode them, do not use CompressedOops::decode_not_null. Use this
141 // function instead.
142 inline static oop decode_with_archived_oop_encoding_mode(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
143
144 static void init_narrow_oop_decoding(address base, int shift) NOT_CDS_JAVA_HEAP_RETURN;
145
146 static void patch_archived_heap_embedded_pointers(MemRegion mem, address oopmap,
147 size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
148
149 static void init_archivable_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
150 static void archive_module_graph_objects(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
151
152 #if INCLUDE_CDS_JAVA_HEAP
153 static ResourceBitMap calculate_oopmap(MemRegion region);
154 #endif
155 };
156 #endif // SHARE_VM_MEMORY_HEAPSHARED_HPP