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
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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/cds_globals.hpp"
29 #include "cds/serializeClosure.hpp"
30 #include "logging/log.hpp"
31 #include "memory/metaspace.hpp"
32 #include "memory/virtualspace.hpp"
33 #include "utilities/bitMap.hpp"
34 #include "utilities/exceptions.hpp"
35 #include "utilities/macros.hpp"
36
37 class BootstrapInfo;
38 class ReservedSpace;
39 class VirtualSpace;
40
41 template<class E> class Array;
42 template<class E> class GrowableArray;
43
44 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
45 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
46 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
47 // fixed, but _ptr_end can be expanded as more objects are dumped.
48 class ArchivePtrMarker : AllStatic {
49 static CHeapBitMap* _ptrmap;
50 static CHeapBitMap* _rw_ptrmap;
51 static CHeapBitMap* _ro_ptrmap;
52 static VirtualSpace* _vs;
53
54 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
55 // avoid unintentional copy operations after the bitmap has been finalized and written.
56 static bool _compacted;
57
58 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
59 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
60
61 public:
62 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
63 static void initialize_rw_ro_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap);
64 static void mark_pointer(address* ptr_loc);
65 static void clear_pointer(address* ptr_loc);
66 static void compact(address relocatable_base, address relocatable_end);
67 static void compact(size_t max_non_null_offset);
68
69 template <typename T>
70 static void mark_pointer(T* ptr_loc) {
71 mark_pointer((address*)ptr_loc);
72 }
73
74 template <typename T>
75 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
76 *ptr_loc = ptr_value;
77 mark_pointer(ptr_loc);
78 }
79
80 static CHeapBitMap* ptrmap() {
81 return _ptrmap;
82 }
83
84 static CHeapBitMap* rw_ptrmap() {
85 return _rw_ptrmap;
86 }
87
88 static CHeapBitMap* ro_ptrmap() {
89 return _ro_ptrmap;
90 }
91
92 static void reset_map_and_vs() {
93 _ptrmap = nullptr;
94 _rw_ptrmap = nullptr;
95 _ro_ptrmap = nullptr;
96 _vs = nullptr;
97 }
98 };
99
100 // SharedDataRelocator is used to shift pointers in the CDS archive.
101 //
102 // The CDS archive is basically a contiguous block of memory (divided into several regions)
103 // that contains multiple objects. The objects may contain direct pointers that point to other objects
104 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
105 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
106 //
107 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
108 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
109 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
110 // the actually mapped location of the target object.
111 class SharedDataRelocator: public BitMapClosure {
112 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
113
114 // Patch all pointers within this region that are marked.
115 address* _patch_base;
116 address* _patch_end;
117
118 // Before patching, all pointers must point to this region.
119 address _valid_old_base;
120 address _valid_old_end;
121
122 // After patching, all pointers must point to this region.
123 address _valid_new_base;
124 address _valid_new_end;
125
126 // How much to relocate for each pointer.
127 intx _delta;
128
129 public:
130 SharedDataRelocator(address* patch_base, address* patch_end,
131 address valid_old_base, address valid_old_end,
132 address valid_new_base, address valid_new_end, intx delta) :
133 _patch_base(patch_base), _patch_end(patch_end),
134 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
135 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
136 _delta(delta) {
137 log_debug(cds, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
138 log_debug(cds, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
139 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
140 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
141 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
142 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
143 }
144
145 bool do_bit(size_t offset);
146 };
147
148 class DumpRegion {
149 private:
150 const char* _name;
151 char* _base;
152 char* _top;
153 char* _end;
154 uintx _max_delta;
155 bool _is_packed;
156 ReservedSpace* _rs;
157 VirtualSpace* _vs;
158
159 void commit_to(char* newtop);
160
161 public:
162 DumpRegion(const char* name, uintx max_delta = 0)
163 : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
164 _max_delta(max_delta), _is_packed(false),
165 _rs(NULL), _vs(NULL) {}
166
167 char* expand_top_to(char* newtop);
168 char* allocate(size_t num_bytes, size_t alignment = 0);
169
170 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
171
172 char* base() const { return _base; }
173 char* top() const { return _top; }
174 char* end() const { return _end; }
175 size_t reserved() const { return _end - _base; }
176 size_t used() const { return _top - _base; }
177 bool is_packed() const { return _is_packed; }
178 bool is_allocatable() const {
179 return !is_packed() && _base != nullptr;
180 }
181
182 void print(size_t total_bytes) const;
183 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
184
185 void init(ReservedSpace* rs, VirtualSpace* vs);
186
187 void pack(DumpRegion* next = nullptr);
188
189 bool contains(char* p) {
190 return base() <= p && p < top();
191 }
192 };
193
194 // Closure for serializing initialization data out to a data area to be
195 // written to the shared file.
196
197 class WriteClosure : public SerializeClosure {
198 private:
199 DumpRegion* _dump_region;
200
201 public:
202 WriteClosure(DumpRegion* r) {
203 _dump_region = r;
204 }
205
206 void do_ptr(void** p);
207
208 void do_u4(u4* p) {
209 _dump_region->append_intptr_t((intptr_t)(*p));
210 }
211
212 void do_int(int* p) {
213 _dump_region->append_intptr_t((intptr_t)(*p));
214 }
215
216 void do_bool(bool *p) {
217 _dump_region->append_intptr_t((intptr_t)(*p));
218 }
219
220 void do_tag(int tag) {
221 _dump_region->append_intptr_t((intptr_t)tag);
222 }
223
224 char* region_top() {
225 return _dump_region->top();
226 }
227
228 bool reading() const { return false; }
229 };
230
231 // Closure for serializing initialization data in from a data area
232 // (ptr_array) read from the shared file.
233
234 class ReadClosure : public SerializeClosure {
235 private:
236 intptr_t** _ptr_array;
237 intptr_t _base_address;
238 inline intptr_t nextPtr() {
239 return *(*_ptr_array)++;
240 }
241
242 public:
243 ReadClosure(intptr_t** ptr_array, intptr_t base_address) :
244 _ptr_array(ptr_array), _base_address(base_address) {}
245
246 void do_ptr(void** p);
247 void do_u4(u4* p);
248 void do_int(int* p);
249 void do_bool(bool *p);
250 void do_tag(int tag);
251 bool reading() const { return true; }
252 char* region_top() { return nullptr; }
253 };
254
255 class ArchiveUtils {
256 public:
257 static const uintx MAX_SHARED_DELTA = 0x7FFFFFFF;
258 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
259 static bool has_aot_initialized_mirror(InstanceKlass* src_ik);
260 template <typename T> static Array<T>* archive_array(GrowableArray<T>* tmp_array);
261
262 // offset must represent an object of type T in the mapped shared space. Return
263 // a direct pointer to this object.
264 template <typename T> T static from_offset(u4 offset) {
265 T p = (T)(SharedBaseAddress + offset);
266 assert(Metaspace::is_in_shared_metaspace(p), "must be");
267 return p;
268 }
269
270 // p must be an archived object. Get its offset from SharedBaseAddress
271 template <typename T> static u4 to_offset(T p) {
272 uintx pn = (uintx)p;
273 uintx base = (uintx)SharedBaseAddress;
274 assert(Metaspace::is_in_shared_metaspace(p), "must be");
275 assert(pn > base, "sanity"); // No valid object is stored at 0 offset from SharedBaseAddress
276 uintx offset = pn - base;
277 assert(offset <= MAX_SHARED_DELTA, "range check");
278 return static_cast<u4>(offset);
279 }
280 };
281
282 class HeapRootSegments {
283 private:
284 size_t _base_offset;
285 size_t _count;
286 int _roots_count;
287 int _max_size_in_bytes;
288 int _max_size_in_elems;
289
290 public:
291 size_t base_offset() { return _base_offset; }
292 size_t count() { return _count; }
293 int roots_count() { return _roots_count; }
294 int max_size_in_bytes() { return _max_size_in_bytes; }
295 int max_size_in_elems() { return _max_size_in_elems; }
296
297 size_t size_in_bytes(size_t seg_idx);
298 int size_in_elems(size_t seg_idx);
299 size_t segment_offset(size_t seg_idx);
300
301 // Trivial copy assignments are allowed to copy the entire object representation.
302 // We also inline this class into archive header. Therefore, it is important to make
303 // sure any gaps in object representation are initialized to zeroes. This is why
304 // constructors memset before doing field assignments.
305 HeapRootSegments() {
306 memset(this, 0, sizeof(*this));
307 }
308 HeapRootSegments(size_t base_offset, int roots_count, int max_size_in_bytes, int max_size_in_elems) {
309 memset(this, 0, sizeof(*this));
310 _base_offset = base_offset;
311 _count = (roots_count + max_size_in_elems - 1) / max_size_in_elems;
312 _roots_count = roots_count;
313 _max_size_in_bytes = max_size_in_bytes;
314 _max_size_in_elems = max_size_in_elems;
315 }
316
317 // This class is trivially copyable and assignable.
318 HeapRootSegments(const HeapRootSegments&) = default;
319 HeapRootSegments& operator=(const HeapRootSegments&) = default;
320 };
321
322 #endif // SHARE_CDS_ARCHIVEUTILS_HPP