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/growableArray.hpp"
34
35 #if INCLUDE_CDS_JAVA_HEAP
36 // A dump time sub-graph info for Klass _k. It includes the entry points
37 // (static fields in _k's mirror) of the archived sub-graphs reachable
38 // from _k's mirror. It also contains a list of Klasses of the objects
39 // within the sub-graphs.
40 class KlassSubGraphInfo: public CHeapObj<mtClass> {
41 private:
42 KlassSubGraphInfo* _next;
43 // The class that contains the static field(s) as the entry point(s)
44 // of archived object sub-graph(s).
45 Klass* _k;
46 // A list of classes need to be loaded and initialized before the archived
47 // object sub-graphs can be accessed at runtime.
48 GrowableArray<Klass*>* _subgraph_object_klasses;
49 // A list of _k's static fields as the entry points of archived sub-graphs.
50 // For each entry field, it is a pair of field_offset and field_value.
51 GrowableArray<juint>* _subgraph_entry_fields;
52
53 public:
54 KlassSubGraphInfo(Klass* k, KlassSubGraphInfo* next) :
55 _next(next), _k(k), _subgraph_object_klasses(NULL),
56 _subgraph_entry_fields(NULL) {}
57 ~KlassSubGraphInfo() {
58 if (_subgraph_object_klasses != NULL) {
59 delete _subgraph_object_klasses;
60 }
61 if (_subgraph_entry_fields != NULL) {
62 delete _subgraph_entry_fields;
63 }
64 };
65
66 KlassSubGraphInfo* next() { return _next; }
67 Klass* klass() { return _k; }
68 GrowableArray<Klass*>* subgraph_object_klasses() {
69 return _subgraph_object_klasses;
70 }
71 GrowableArray<juint>* subgraph_entry_fields() {
72 return _subgraph_entry_fields;
73 }
74 void add_subgraph_entry_field(int static_field_offset, oop v);
75 void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);
76 };
77
78 // An archived record of object sub-graphs reachable from static
79 // fields within _k's mirror. The record is reloaded from the archive
80 // at runtime.
81 class ArchivedKlassSubGraphInfoRecord {
82 private:
83 ArchivedKlassSubGraphInfoRecord* _next;
84 Klass* _k;
85
86 // contains pairs of field offset and value for each subgraph entry field
87 Array<juint>* _entry_field_records;
88
89 // klasses of objects in archived sub-graphs referenced from the entry points
90 // (static fields) in the containing class
91 Array<Klass*>* _subgraph_klasses;
92 public:
93 ArchivedKlassSubGraphInfoRecord() :
94 _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_klasses(NULL) {}
95 void init(KlassSubGraphInfo* info);
96 Klass* klass() { return _k; }
97 ArchivedKlassSubGraphInfoRecord* next() { return _next; }
98 void set_next(ArchivedKlassSubGraphInfoRecord* next) { _next = next; }
99 Array<juint>* entry_field_records() { return _entry_field_records; }
100 Array<Klass*>* subgraph_klasses() { return _subgraph_klasses; }
101 };
102 #endif // INCLUDE_CDS_JAVA_HEAP
103
104 class HeapShared: AllStatic {
105 private:
106 #if INCLUDE_CDS_JAVA_HEAP
107 // This is a list of subgraph infos built at dump time while
108 // archiving object subgraphs.
109 static KlassSubGraphInfo* _subgraph_info_list;
110
111 // Contains a list of ArchivedKlassSubGraphInfoRecords that is stored
112 // in the archive file and reloaded at runtime.
113 static int _num_archived_subgraph_info_records;
114 static Array<ArchivedKlassSubGraphInfoRecord>* _archived_subgraph_info_records;
115
116 // Archive object sub-graph starting from the given static field
117 // in Klass k's mirror.
118 static void archive_reachable_objects_from_static_field(
119 Klass* k, int field_ofset, BasicType field_type, TRAPS);
120
121 static KlassSubGraphInfo* find_subgraph_info(Klass *k);
122 static KlassSubGraphInfo* get_subgraph_info(Klass *k);
123 static int num_of_subgraph_infos();
124
125 static size_t build_archived_subgraph_info_records(int num_records);
126 #endif // INCLUDE_CDS_JAVA_HEAP
127 public:
128 static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);
129 static void write_archived_subgraph_infos() NOT_CDS_JAVA_HEAP_RETURN;
130 static void initialize_from_archived_subgraph(Klass* k) NOT_CDS_JAVA_HEAP_RETURN;
131
132 static void archive_module_graph_objects(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
133 };
134 #endif // SHARE_VM_MEMORY_HEAPSHARED_HPP