1 /*
2 * Copyright (c) 2019, 2026, 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_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 "runtime/nonJavaThread.hpp"
34 #include "runtime/semaphore.hpp"
35 #include "utilities/bitMap.hpp"
36 #include "utilities/exceptions.hpp"
37 #include "utilities/macros.hpp"
38
39 class BootstrapInfo;
40 class ReservedSpace;
41 class VirtualSpace;
42
43 template<class E> class Array;
44 template<class E> class GrowableArray;
45
46 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
47 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
48 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
49 // fixed, but _ptr_end can be expanded as more objects are dumped.
50 class ArchivePtrMarker : AllStatic {
51 static CHeapBitMap* _ptrmap;
52 static CHeapBitMap* _rw_ptrmap;
53 static CHeapBitMap* _ro_ptrmap;
54 static VirtualSpace* _vs;
55
56 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
57 // avoid unintentional copy operations after the bitmap has been finalized and written.
58 static bool _compacted;
59
60 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
61 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
62
63 public:
64 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
65 static void initialize_rw_ro_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap);
66 static void mark_pointer(address* ptr_loc);
67 static void clear_pointer(address* ptr_loc);
68 static void compact(address relocatable_base, address relocatable_end);
69 static void compact(size_t max_non_null_offset);
70
71 template <typename T>
72 static void mark_pointer(T* ptr_loc) {
73 mark_pointer((address*)ptr_loc);
74 }
75
76 template <typename T>
77 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
78 *ptr_loc = ptr_value;
79 mark_pointer(ptr_loc);
80 }
81
82 static CHeapBitMap* ptrmap() {
83 return _ptrmap;
84 }
85
86 static CHeapBitMap* rw_ptrmap() {
87 return _rw_ptrmap;
88 }
89
90 static CHeapBitMap* ro_ptrmap() {
91 return _ro_ptrmap;
92 }
93
94 static void reset_map_and_vs() {
95 _ptrmap = nullptr;
96 _rw_ptrmap = nullptr;
97 _ro_ptrmap = nullptr;
98 _vs = nullptr;
99 }
100 };
101
102 // SharedDataRelocator is used to shift pointers in the CDS archive.
103 //
104 // The CDS archive is basically a contiguous block of memory (divided into several regions)
105 // that contains multiple objects. The objects may contain direct pointers that point to other objects
106 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
107 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
108 //
109 // The contents of the archive assumes that it's mapped at the default SharedBaseAddress (e.g. 0x800000000).
110 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
111 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
112 // the actually mapped location of the target object.
113 class SharedDataRelocator: public BitMapClosure {
114 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
115
116 // Patch all pointers within this region that are marked.
117 address* _patch_base;
118 address* _patch_end;
119
120 // Before patching, all pointers must point to this region.
121 address _valid_old_base;
122 address _valid_old_end;
123
124 // After patching, all pointers must point to this region.
125 address _valid_new_base;
126 address _valid_new_end;
127
128 // How much to relocate for each pointer.
129 intx _delta;
130
131 public:
132 SharedDataRelocator(address* patch_base, address* patch_end,
133 address valid_old_base, address valid_old_end,
134 address valid_new_base, address valid_new_end, intx delta) :
135 _patch_base(patch_base), _patch_end(patch_end),
136 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
137 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
138 _delta(delta) {
139 log_debug(aot, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
140 log_debug(aot, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
141 log_debug(aot, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
142 log_debug(aot, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
143 log_debug(aot, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
144 log_debug(aot, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
145 }
146
147 bool do_bit(size_t offset);
148 };
149
150 class DumpRegion {
151 private:
152 const char* _name;
153 char* _base;
154 char* _top;
155 char* _end;
156 bool _is_packed;
157 ReservedSpace* _rs;
158 VirtualSpace* _vs;
159
160 void commit_to(char* newtop);
161
162 public:
163 DumpRegion(const char* name)
164 : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
165 _is_packed(false),
166 _rs(nullptr), _vs(nullptr) {}
167
168 char* expand_top_to(char* newtop);
169 char* allocate(size_t num_bytes, size_t alignment = 0);
170
171 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
172
173 char* base() const { return _base; }
174 char* top() const { return _top; }
175 char* end() const { return _end; }
176 size_t reserved() const { return _end - _base; }
177 size_t used() const { return _top - _base; }
178 bool is_packed() const { return _is_packed; }
179 bool is_allocatable() const {
180 return !is_packed() && _base != nullptr;
181 }
182 bool is_empty() const { return _base == _top; }
183
184 void print(size_t total_bytes) const;
185 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
186
187 void init(ReservedSpace* rs, VirtualSpace* vs);
188
189 void pack(DumpRegion* next = nullptr);
190
191 bool contains(char* p) {
192 return base() <= p && p < top();
193 }
194 };
195
196 // Closure for serializing initialization data out to a data area to be
197 // written to the shared file.
198
199 class WriteClosure : public SerializeClosure {
200 private:
201 DumpRegion* _dump_region;
202
203 public:
204 WriteClosure(DumpRegion* r) {
205 _dump_region = r;
206 }
207
208 void do_ptr(void** p);
209
210 void do_u4(u4* p) {
211 _dump_region->append_intptr_t((intptr_t)(*p));
212 }
213
214 void do_int(int* p) {
215 _dump_region->append_intptr_t((intptr_t)(*p));
216 }
217
218 void do_bool(bool *p) {
219 _dump_region->append_intptr_t((intptr_t)(*p));
220 }
221
222 void do_tag(int tag) {
223 _dump_region->append_intptr_t((intptr_t)tag);
224 }
225
226 char* region_top() {
227 return _dump_region->top();
228 }
229
230 bool reading() const { return false; }
231 };
232
233 // Closure for serializing initialization data in from a data area
234 // (ptr_array) read from the shared file.
235
236 class ReadClosure : public SerializeClosure {
237 private:
238 intptr_t** _ptr_array;
239 address _base_address;
240 inline intptr_t nextPtr() {
241 return *(*_ptr_array)++;
242 }
243
244 public:
245 ReadClosure(intptr_t** ptr_array, address base_address) :
246 _ptr_array(ptr_array), _base_address(base_address) {}
247
248 void do_ptr(void** p);
249 void do_u4(u4* p);
250 void do_int(int* p);
251 void do_bool(bool *p);
252 void do_tag(int tag);
253 bool reading() const { return true; }
254 char* region_top() { return nullptr; }
255 };
256
257 class ArchiveUtils {
258 template <typename T> static Array<T>* archive_non_ptr_array(GrowableArray<T>* tmp_array);
259 template <typename T> static Array<T>* archive_ptr_array(GrowableArray<T>* tmp_array);
260
261 public:
262 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
263 static bool has_aot_initialized_mirror(InstanceKlass* src_ik);
264
265 template <typename T, ENABLE_IF(!std::is_pointer<T>::value)>
266 static Array<T>* archive_array(GrowableArray<T>* tmp_array) {
267 return archive_non_ptr_array(tmp_array);
268 }
269
270 template <typename T, ENABLE_IF(std::is_pointer<T>::value)>
271 static Array<T>* archive_array(GrowableArray<T>* tmp_array) {
272 return archive_ptr_array(tmp_array);
273 }
274 };
275
276 class HeapRootSegments {
277 private:
278 size_t _base_offset;
279 size_t _count;
280 int _roots_count;
281 size_t _max_size_in_bytes;
282 int _max_size_in_elems;
283
284 public:
285 size_t base_offset() { return _base_offset; }
286 size_t count() { return _count; }
287 int roots_count() { return _roots_count; }
288 size_t max_size_in_bytes() { return _max_size_in_bytes; }
289 int max_size_in_elems() { return _max_size_in_elems; }
290
291 size_t size_in_bytes(size_t seg_idx);
292 int size_in_elems(size_t seg_idx);
293 size_t segment_offset(size_t seg_idx);
294
295 // Trivial copy assignments are allowed to copy the entire object representation.
296 // We also inline this class into archive header. Therefore, it is important to make
297 // sure any gaps in object representation are initialized to zeroes. This is why
298 // constructors memset before doing field assignments.
299 HeapRootSegments() {
300 memset(this, 0, sizeof(*this));
301 }
302 HeapRootSegments(size_t base_offset, int roots_count, int max_size_in_bytes, int max_size_in_elems) {
303 memset(this, 0, sizeof(*this));
304 _base_offset = base_offset;
305 _count = (roots_count + max_size_in_elems - 1) / max_size_in_elems;
306 _roots_count = roots_count;
307 _max_size_in_bytes = max_size_in_bytes;
308 _max_size_in_elems = max_size_in_elems;
309 }
310
311 // This class is trivially copyable and assignable.
312 HeapRootSegments(const HeapRootSegments&) = default;
313 HeapRootSegments& operator=(const HeapRootSegments&) = default;
314 };
315
316 class ArchiveWorkers;
317
318 // A task to be worked on by worker threads
319 class ArchiveWorkerTask : public CHeapObj<mtInternal> {
320 friend class ArchiveWorkers;
321 private:
322 const char* _name;
323 int _max_chunks;
324 volatile int _chunk;
325
326 void run();
327
328 void configure_max_chunks(int max_chunks);
329
330 public:
331 ArchiveWorkerTask(const char* name) :
332 _name(name), _max_chunks(0), _chunk(0) {}
333 const char* name() const { return _name; }
334 virtual void work(int chunk, int max_chunks) = 0;
335 };
336
337 class ArchiveWorkerThread : public NamedThread {
338 friend class ArchiveWorkers;
339 private:
340 ArchiveWorkers* const _pool;
341
342 void post_run() override;
343
344 public:
345 ArchiveWorkerThread(ArchiveWorkers* pool);
346 const char* type_name() const override { return "Archive Worker Thread"; }
347 void run() override;
348 };
349
350 // Special archive workers. The goal for this implementation is to startup fast,
351 // distribute spiky workloads efficiently, and shutdown immediately after use.
352 // This makes the implementation quite different from the normal GC worker pool.
353 class ArchiveWorkers : public StackObj {
354 friend class ArchiveWorkerThread;
355 private:
356 // Target number of chunks per worker. This should be large enough to even
357 // out work imbalance, and small enough to keep bookkeeping overheads low.
358 static constexpr int CHUNKS_PER_WORKER = 4;
359 static int max_workers();
360
361 Semaphore _end_semaphore;
362
363 int _num_workers;
364 int _started_workers;
365 int _finish_tokens;
366
367 typedef enum { UNUSED, WORKING, SHUTDOWN } State;
368 volatile State _state;
369
370 ArchiveWorkerTask* _task;
371
372 void run_as_worker();
373 void start_worker_if_needed();
374
375 void run_task_single(ArchiveWorkerTask* task);
376 void run_task_multi(ArchiveWorkerTask* task);
377
378 bool is_parallel();
379
380 public:
381 ArchiveWorkers();
382 ~ArchiveWorkers();
383 void run_task(ArchiveWorkerTask* task);
384 };
385
386 #endif // SHARE_CDS_ARCHIVEUTILS_HPP