1 /*
2 * Copyright (c) 2019, 2024, 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.
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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
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23 */
24
25 #ifndef SHARE_CDS_ARCHIVEUTILS_HPP
26 #define SHARE_CDS_ARCHIVEUTILS_HPP
27
28 #include "cds/serializeClosure.hpp"
29 #include "logging/log.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/bitMap.hpp"
32 #include "utilities/exceptions.hpp"
33 #include "utilities/macros.hpp"
34
35 class BootstrapInfo;
36 class ReservedSpace;
37 class VirtualSpace;
38
39 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
40 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
41 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
42 // fixed, but _ptr_end can be expanded as more objects are dumped.
43 class ArchivePtrMarker : AllStatic {
44 static CHeapBitMap* _ptrmap;
45 static CHeapBitMap* _rw_ptrmap;
46 static CHeapBitMap* _ro_ptrmap;
47 static VirtualSpace* _vs;
48
49 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
50 // avoid unintentional copy operations after the bitmap has been finalized and written.
51 static bool _compacted;
52
53 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
54 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
55
56 public:
57 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
58 static void initialize_rw_ro_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap);
59 static void mark_pointer(address* ptr_loc);
60 static void clear_pointer(address* ptr_loc);
61 static void compact(address relocatable_base, address relocatable_end);
62 static void compact(size_t max_non_null_offset);
63
64 template <typename T>
65 static void mark_pointer(T* ptr_loc) {
66 mark_pointer((address*)ptr_loc);
67 }
68
69 template <typename T>
70 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
71 *ptr_loc = ptr_value;
72 mark_pointer(ptr_loc);
73 }
74
75 static CHeapBitMap* ptrmap() {
76 return _ptrmap;
77 }
78
79 static CHeapBitMap* rw_ptrmap() {
80 return _rw_ptrmap;
81 }
82
83 static CHeapBitMap* ro_ptrmap() {
84 return _ro_ptrmap;
85 }
86
87 static void reset_map_and_vs() {
88 _ptrmap = nullptr;
89 _rw_ptrmap = nullptr;
90 _ro_ptrmap = nullptr;
91 _vs = nullptr;
92 }
93 };
94
95 // SharedDataRelocator is used to shift pointers in the CDS archive.
96 //
97 // The CDS archive is basically a contiguous block of memory (divided into several regions)
98 // that contains multiple objects. The objects may contain direct pointers that point to other objects
99 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
100 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
101 //
102 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
103 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
104 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
105 // the actually mapped location of the target object.
106 class SharedDataRelocator: public BitMapClosure {
107 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
108
109 // Patch all pointers within this region that are marked.
110 address* _patch_base;
111 address* _patch_end;
112
113 // Before patching, all pointers must point to this region.
114 address _valid_old_base;
115 address _valid_old_end;
116
117 // After patching, all pointers must point to this region.
118 address _valid_new_base;
119 address _valid_new_end;
120
121 // How much to relocate for each pointer.
122 intx _delta;
123
124 public:
125 SharedDataRelocator(address* patch_base, address* patch_end,
126 address valid_old_base, address valid_old_end,
127 address valid_new_base, address valid_new_end, intx delta) :
128 _patch_base(patch_base), _patch_end(patch_end),
129 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
130 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
131 _delta(delta) {
132 log_debug(cds, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
133 log_debug(cds, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
134 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
135 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
136 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
137 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
138 }
139
140 bool do_bit(size_t offset);
141 };
142
143 class DumpRegion {
144 private:
145 const char* _name;
146 char* _base;
147 char* _top;
148 char* _end;
149 uintx _max_delta;
150 bool _is_packed;
151 ReservedSpace* _rs;
152 VirtualSpace* _vs;
153
154 void commit_to(char* newtop);
155
156 public:
157 DumpRegion(const char* name, uintx max_delta = 0)
158 : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
159 _max_delta(max_delta), _is_packed(false) {}
160
161 char* expand_top_to(char* newtop);
162 char* allocate(size_t num_bytes);
163
164 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
165
166 char* base() const { return _base; }
167 char* top() const { return _top; }
168 char* end() const { return _end; }
169 size_t reserved() const { return _end - _base; }
170 size_t used() const { return _top - _base; }
171 bool is_packed() const { return _is_packed; }
172 bool is_allocatable() const {
173 return !is_packed() && _base != nullptr;
174 }
175
176 void print(size_t total_bytes) const;
177 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
178
179 void init(ReservedSpace* rs, VirtualSpace* vs);
180
181 void pack(DumpRegion* next = nullptr);
182
183 bool contains(char* p) {
184 return base() <= p && p < top();
185 }
186 };
187
188 // Closure for serializing initialization data out to a data area to be
189 // written to the shared file.
190
191 class WriteClosure : public SerializeClosure {
192 private:
193 DumpRegion* _dump_region;
194
195 public:
196 WriteClosure(DumpRegion* r) {
197 _dump_region = r;
198 }
199
200 void do_ptr(void** p);
201
202 void do_u4(u4* p) {
203 _dump_region->append_intptr_t((intptr_t)(*p));
204 }
205
206 void do_int(int* p) {
207 _dump_region->append_intptr_t((intptr_t)(*p));
208 }
209
210 void do_bool(bool *p) {
211 _dump_region->append_intptr_t((intptr_t)(*p));
212 }
213
214 void do_tag(int tag) {
215 _dump_region->append_intptr_t((intptr_t)tag);
216 }
217
218 char* region_top() {
219 return _dump_region->top();
220 }
221
222 bool reading() const { return false; }
223 };
224
225 // Closure for serializing initialization data in from a data area
226 // (ptr_array) read from the shared file.
227
228 class ReadClosure : public SerializeClosure {
229 private:
230 intptr_t** _ptr_array;
231
232 inline intptr_t nextPtr() {
233 return *(*_ptr_array)++;
234 }
235
236 public:
237 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
238
239 void do_ptr(void** p);
240 void do_u4(u4* p);
241 void do_int(int* p);
242 void do_bool(bool *p);
243 void do_tag(int tag);
244 bool reading() const { return true; }
245 char* region_top() { return nullptr; }
246 };
247
248 class ArchiveUtils {
249 public:
250 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
251 };
252
253 class HeapRootSegments {
254 private:
255 size_t _base_offset;
256 size_t _count;
257 int _roots_count;
258 int _max_size_in_bytes;
259 int _max_size_in_elems;
260
261 public:
262 size_t base_offset() { return _base_offset; }
263 size_t count() { return _count; }
264 int roots_count() { return _roots_count; }
265 int max_size_in_bytes() { return _max_size_in_bytes; }
266 int max_size_in_elems() { return _max_size_in_elems; }
267
268 size_t size_in_bytes(size_t seg_idx);
269 int size_in_elems(size_t seg_idx);
270 size_t segment_offset(size_t seg_idx);
271
272 // Trivial copy assignments are allowed to copy the entire object representation.
273 // We also inline this class into archive header. Therefore, it is important to make
274 // sure any gaps in object representation are initialized to zeroes. This is why
275 // constructors memset before doing field assignments.
276 HeapRootSegments() {
277 memset(this, 0, sizeof(*this));
278 }
279 HeapRootSegments(size_t base_offset, int roots_count, int max_size_in_bytes, int max_size_in_elems) {
280 memset(this, 0, sizeof(*this));
281 _base_offset = base_offset;
282 _count = (roots_count + max_size_in_elems - 1) / max_size_in_elems;
283 _roots_count = roots_count;
284 _max_size_in_bytes = max_size_in_bytes;
285 _max_size_in_elems = max_size_in_elems;
286 }
287
288 // This class is trivially copyable and assignable.
289 HeapRootSegments(const HeapRootSegments&) = default;
290 HeapRootSegments& operator=(const HeapRootSegments&) = default;
291 };
292
293 #endif // SHARE_CDS_ARCHIVEUTILS_HPP