1 /*
2 * Copyright (c) 2018, 2025, 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.
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23 */
24
25 #ifndef SHARE_CDS_ARCHIVEHEAPLOADER_HPP
26 #define SHARE_CDS_ARCHIVEHEAPLOADER_HPP
27
28 #include "gc/shared/gc_globals.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/allStatic.hpp"
31 #include "memory/memRegion.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "runtime/globals.hpp"
34 #include "utilities/bitMap.hpp"
35 #include "utilities/macros.hpp"
36
37 class FileMapInfo;
38 struct LoadedArchiveHeapRegion;
39
40 class ArchiveHeapLoader : AllStatic {
41 public:
42 // At runtime, the heap region in the CDS archive can be used in two different ways,
43 // depending on the GC type:
44 // - Mapped: (G1 only) the region is directly mapped into the Java heap
45 // - Loaded: At VM start-up, the objects in the heap region are copied into the
46 // Java heap. This is easier to implement than mapping but
47 // slightly less efficient, as the embedded pointers need to be relocated.
48 static bool can_use() { return can_map() || can_load(); }
49
50 // Can this VM map archived heap region? Currently only G1+compressed{oops,cp}
51 static bool can_map() {
52 CDS_JAVA_HEAP_ONLY(return (UseG1GC && UseCompressedClassPointers);)
53 NOT_CDS_JAVA_HEAP(return false;)
54 }
55
56 // Can this VM load the objects from archived heap region into the heap at start-up?
57 static bool can_load() NOT_CDS_JAVA_HEAP_RETURN_(false);
58 static void finish_initialization() NOT_CDS_JAVA_HEAP_RETURN;
59 static bool is_loaded() {
60 CDS_JAVA_HEAP_ONLY(return _is_loaded;)
61 NOT_CDS_JAVA_HEAP(return false;)
62 }
63
64 static bool is_in_use() {
65 return is_loaded() || is_mapped();
66 }
67
68 static ptrdiff_t mapped_heap_delta() {
69 CDS_JAVA_HEAP_ONLY(assert(!is_loaded(), "must be"));
70 CDS_JAVA_HEAP_ONLY(assert(_mapped_heap_relocation_initialized, "must be"));
71 CDS_JAVA_HEAP_ONLY(return _mapped_heap_delta;)
72 NOT_CDS_JAVA_HEAP_RETURN_(0L);
73 }
74
75 static void set_mapped() {
76 CDS_JAVA_HEAP_ONLY(_is_mapped = true;)
77 NOT_CDS_JAVA_HEAP_RETURN;
78 }
79 static bool is_mapped() {
80 CDS_JAVA_HEAP_ONLY(return _is_mapped;)
81 NOT_CDS_JAVA_HEAP_RETURN_(false);
82 }
83
84 // NarrowOops stored in the CDS archive may use a different encoding scheme
85 // than CompressedOops::{base,shift} -- see FileMapInfo::map_heap_region_impl.
86 // To decode them, do not use CompressedOops::decode_not_null. Use this
87 // function instead.
88 inline static oop decode_from_archive(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
89
90 // More efficient version, but works only when ArchiveHeap is mapped.
91 inline static oop decode_from_mapped_archive(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
92
93 static void patch_compressed_embedded_pointers(BitMapView bm,
94 FileMapInfo* info,
95 MemRegion region) NOT_CDS_JAVA_HEAP_RETURN;
96
97 static void patch_embedded_pointers(FileMapInfo* info,
98 MemRegion region, address oopmap,
99 size_t oopmap_size_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
100
101 static void fixup_region() NOT_CDS_JAVA_HEAP_RETURN;
102
103 #if INCLUDE_CDS_JAVA_HEAP
104 static void init_mapped_heap_info(address mapped_heap_bottom, ptrdiff_t delta, int dumptime_oop_shift);
105 private:
106 static bool _is_mapped;
107 static bool _is_loaded;
108
109 // Support for loaded archived heap. These are cached values from
110 // LoadedArchiveHeapRegion's.
111 static uintptr_t _dumptime_base;
112 static uintptr_t _dumptime_top;
113 static intx _runtime_offset;
114
115 static uintptr_t _loaded_heap_bottom;
116 static uintptr_t _loaded_heap_top;
117 static bool _loading_failed;
118
119 // UseCompressedOops only: Used by decode_from_archive
120 static bool _narrow_oop_base_initialized;
121 static address _narrow_oop_base;
122 static int _narrow_oop_shift;
123
124 // is_mapped() only: the mapped address of each region is offset by this amount from
125 // their requested address.
126 static uintptr_t _mapped_heap_bottom;
127 static ptrdiff_t _mapped_heap_delta;
128 static bool _mapped_heap_relocation_initialized;
129
130 static void init_narrow_oop_decoding(address base, int shift);
131 static bool init_loaded_region(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region,
132 MemRegion& archive_space);
133 static bool load_heap_region_impl(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region, uintptr_t buffer);
134 static void init_loaded_heap_relocation(LoadedArchiveHeapRegion* reloc_info);
135 static void patch_native_pointers();
136 static void finish_loaded_heap();
137 static void verify_loaded_heap();
138 static void fill_failed_loaded_heap();
139
140 static bool is_in_loaded_heap(uintptr_t o) {
141 return (_loaded_heap_bottom <= o && o < _loaded_heap_top);
142 }
143
144 template<bool IS_MAPPED>
145 inline static oop decode_from_archive_impl(narrowOop v) NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
146
147 class PatchLoadedRegionPointers;
148 class PatchUncompressedLoadedRegionPointers;
149
150 public:
151
152 static bool load_heap_region(FileMapInfo* mapinfo);
153 static void assert_in_loaded_heap(uintptr_t o) {
154 assert(is_in_loaded_heap(o), "must be");
155 }
156 static oop oop_from_offset(int offset);
157 #endif // INCLUDE_CDS_JAVA_HEAP
158
159 };
160
161 #endif // SHARE_CDS_ARCHIVEHEAPLOADER_HPP