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/allocation.hpp"
32 #include "memory/metaspace.hpp"
33 #include "memory/metaspaceClosureType.hpp"
34 #include "memory/virtualspace.hpp"
35 #include "runtime/nonJavaThread.hpp"
36 #include "runtime/semaphore.hpp"
37 #include "utilities/bitMap.hpp"
38 #include "utilities/exceptions.hpp"
39 #include "utilities/macros.hpp"
40
41 class BootstrapInfo;
42 class DumpAllocStats;
43 class ReservedSpace;
44 class VirtualSpace;
45
46 template<class E> class Array;
47 template<class E> class GrowableArray;
48
49 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
50 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
51 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
52 // fixed, but _ptr_end can be expanded as more objects are dumped.
53 class ArchivePtrMarker : AllStatic {
54 static CHeapBitMap* _ptrmap;
55 static CHeapBitMap* _rw_ptrmap;
56 static CHeapBitMap* _ro_ptrmap;
57 static CHeapBitMap* _ac_ptrmap;
58 static VirtualSpace* _vs;
59
60 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
61 // avoid unintentional copy operations after the bitmap has been finalized and written.
62 static bool _compacted;
63
64 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
65 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
66
67 public:
68 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
69 static void initialize_rw_ro_ac_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap, CHeapBitMap* ac_ptrmap);
70 static void mark_pointer(address* ptr_loc);
71 static void clear_pointer(address* ptr_loc);
72 static void compact(address relocatable_base, address relocatable_end);
73 static void compact(size_t max_non_null_offset);
74
75 template <typename T>
76 static void mark_pointer(T* ptr_loc) {
77 mark_pointer((address*)ptr_loc);
78 }
79
80 template <typename T>
81 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
82 *ptr_loc = ptr_value;
83 mark_pointer(ptr_loc);
84 }
85
86 static CHeapBitMap* ptrmap() {
87 return _ptrmap;
88 }
89
90 static CHeapBitMap* rw_ptrmap() {
91 return _rw_ptrmap;
92 }
93
94 static CHeapBitMap* ro_ptrmap() {
95 return _ro_ptrmap;
96 }
97
98 static CHeapBitMap* ac_ptrmap() {
99 return _ac_ptrmap;
100 }
101
102 static void reset_map_and_vs() {
103 _ptrmap = nullptr;
104 _rw_ptrmap = nullptr;
105 _ro_ptrmap = nullptr;
106 _ac_ptrmap = nullptr;
107 _vs = nullptr;
108 }
109 };
110
111 // SharedDataRelocator is used to shift pointers in the CDS archive.
112 //
113 // The CDS archive is basically a contiguous block of memory (divided into several regions)
114 // that contains multiple objects. The objects may contain direct pointers that point to other objects
115 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
116 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
117 //
118 // The contents of the archive assumes that it's mapped at the default SharedBaseAddress (e.g. 0x800000000).
119 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
120 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
121 // the actually mapped location of the target object.
122 class SharedDataRelocator: public BitMapClosure {
123 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
124
125 // Patch all pointers within this region that are marked.
126 address* _patch_base;
127 address* _patch_end;
128
129 // Before patching, all pointers must point to this region.
130 address _valid_old_base;
131 address _valid_old_end;
132
133 // After patching, all pointers must point to this region.
134 address _valid_new_base;
135 address _valid_new_end;
136
137 // How much to relocate for each pointer.
138 intx _delta;
139
140 public:
141 SharedDataRelocator(address* patch_base, address* patch_end,
142 address valid_old_base, address valid_old_end,
143 address valid_new_base, address valid_new_end, intx delta) :
144 _patch_base(patch_base), _patch_end(patch_end),
145 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
146 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
147 _delta(delta) {
148 log_debug(aot, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
149 log_debug(aot, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
150 log_debug(aot, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
151 log_debug(aot, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
152 log_debug(aot, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
153 log_debug(aot, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
154 }
155
156 bool do_bit(size_t offset);
157 };
158
159 class DumpRegion {
160 private:
161 const char* _name;
162 char* _base;
163 char* _top;
164 char* _end;
165 bool _is_packed;
166 ReservedSpace* _rs;
167 VirtualSpace* _vs;
168
169 void commit_to(char* newtop);
170
171 public:
172 // Allocation gaps (due to Klass alignment)
173 class AllocGapTree;
174 class AllocGap;
175 struct AllocGapCmp;
176
177 private:
178 static AllocGapTree _gap_tree;
179 static size_t _total_gap_bytes;
180 static size_t _total_gap_bytes_used;
181 static size_t _total_gap_allocs;
182
183 public:
184 DumpRegion(const char* name)
185 : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
186 _is_packed(false),
187 _rs(nullptr), _vs(nullptr) {}
188
189 char* expand_top_to(char* newtop);
190 char* allocate(size_t num_bytes, size_t alignment = 0);
191 char* allocate_metaspace_obj(size_t num_bytes, address src, MetaspaceClosureType type, bool read_only, DumpAllocStats* stats);
192
193 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
194
195 char* base() const { return _base; }
196 char* top() const { return _top; }
197 char* end() const { return _end; }
198 size_t reserved() const { return _end - _base; }
199 size_t used() const { return _top - _base; }
200 bool is_packed() const { return _is_packed; }
201 bool is_allocatable() const {
202 return !is_packed() && _base != nullptr;
203 }
204 bool is_empty() const { return _base == _top; }
205
206 void print(size_t total_bytes) const;
207 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
208
209 void init(ReservedSpace* rs, VirtualSpace* vs);
210
211 void pack(DumpRegion* next = nullptr);
212
213 bool contains(char* p) {
214 return base() <= p && p < top();
215 }
216
217 static void report_gaps(DumpAllocStats* stats);
218 };
219
220 // Closure for serializing initialization data out to a data area to be
221 // written to the shared file.
222
223 class WriteClosure : public SerializeClosure {
224 private:
225 DumpRegion* _dump_region;
226
227 public:
228 WriteClosure(DumpRegion* r) {
229 _dump_region = r;
230 }
231
232 void do_ptr(void** p);
233
234 void do_u4(u4* p) {
235 _dump_region->append_intptr_t((intptr_t)(*p));
236 }
237
238 void do_int(int* p) {
239 _dump_region->append_intptr_t((intptr_t)(*p));
240 }
241
242 void do_bool(bool *p) {
243 _dump_region->append_intptr_t((intptr_t)(*p));
244 }
245
246 void do_tag(int tag) {
247 _dump_region->append_intptr_t((intptr_t)tag);
248 }
249
250 char* region_top() {
251 return _dump_region->top();
252 }
253
254 bool reading() const { return false; }
255 };
256
257 // Closure for serializing initialization data in from a data area
258 // (ptr_array) read from the shared file.
259
260 class ReadClosure : public SerializeClosure {
261 private:
262 intptr_t** _ptr_array;
263 address _base_address;
264 inline intptr_t nextPtr() {
265 return *(*_ptr_array)++;
266 }
267
268 public:
269 ReadClosure(intptr_t** ptr_array, address base_address) :
270 _ptr_array(ptr_array), _base_address(base_address) {}
271
272 void do_ptr(void** p);
273 void do_u4(u4* p);
274 void do_int(int* p);
275 void do_bool(bool *p);
276 void do_tag(int tag);
277 bool reading() const { return true; }
278 char* region_top() { return nullptr; }
279 };
280
281 class ArchiveUtils {
282 template <typename T> static Array<T>* archive_non_ptr_array(GrowableArray<T>* tmp_array);
283 template <typename T> static Array<T>* archive_ptr_array(GrowableArray<T>* tmp_array);
284
285 public:
286 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
287 static bool has_aot_initialized_mirror(InstanceKlass* src_ik);
288
289 template <typename T, ENABLE_IF(!std::is_pointer<T>::value)>
290 static Array<T>* archive_array(GrowableArray<T>* tmp_array) {
291 return archive_non_ptr_array(tmp_array);
292 }
293
294 template <typename T, ENABLE_IF(std::is_pointer<T>::value)>
295 static Array<T>* archive_array(GrowableArray<T>* tmp_array) {
296 return archive_ptr_array(tmp_array);
297 }
298
299 static const char* builtin_loader_name_or_null(oop loader); // "boot", "platform", "app", or nullptr
300 static const char* builtin_loader_name(oop loader); // "boot", "platform", or "app". Asserts if not a built-in-loader.
301
302 static bool builtin_loader_from_type(const char* loader_type, oop* value_ret);
303 static oop builtin_loader_from_type(int loader_type);
304 };
305
306 class HeapRootSegments {
307 private:
308 size_t _base_offset;
309 size_t _count;
310 int _roots_count;
311 size_t _max_size_in_bytes;
312 int _max_size_in_elems;
313
314 public:
315 size_t base_offset() { return _base_offset; }
316 size_t count() { return _count; }
317 int roots_count() { return _roots_count; }
318 size_t max_size_in_bytes() { return _max_size_in_bytes; }
319 int max_size_in_elems() { return _max_size_in_elems; }
320
321 size_t size_in_bytes(size_t seg_idx);
322 int size_in_elems(size_t seg_idx);
323 size_t segment_offset(size_t seg_idx);
324
325 // Trivial copy assignments are allowed to copy the entire object representation.
326 // We also inline this class into archive header. Therefore, it is important to make
327 // sure any gaps in object representation are initialized to zeroes. This is why
328 // constructors memset before doing field assignments.
329 HeapRootSegments() {
330 memset(this, 0, sizeof(*this));
331 }
332 HeapRootSegments(size_t base_offset, int roots_count, int max_size_in_bytes, int max_size_in_elems) {
333 memset(this, 0, sizeof(*this));
334 _base_offset = base_offset;
335 _count = (roots_count + max_size_in_elems - 1) / max_size_in_elems;
336 _roots_count = roots_count;
337 _max_size_in_bytes = max_size_in_bytes;
338 _max_size_in_elems = max_size_in_elems;
339 }
340
341 // This class is trivially copyable and assignable.
342 HeapRootSegments(const HeapRootSegments&) = default;
343 HeapRootSegments& operator=(const HeapRootSegments&) = default;
344 };
345
346 class ArchiveWorkers;
347
348 // A task to be worked on by worker threads
349 class ArchiveWorkerTask : public CHeapObj<mtInternal> {
350 friend class ArchiveWorkers;
351 private:
352 const char* _name;
353 int _max_chunks;
354 volatile int _chunk;
355
356 void run();
357
358 void configure_max_chunks(int max_chunks);
359
360 public:
361 ArchiveWorkerTask(const char* name) :
362 _name(name), _max_chunks(0), _chunk(0) {}
363 const char* name() const { return _name; }
364 virtual void work(int chunk, int max_chunks) = 0;
365 };
366
367 class ArchiveWorkerThread : public NamedThread {
368 friend class ArchiveWorkers;
369 private:
370 ArchiveWorkers* const _pool;
371
372 void post_run() override;
373
374 public:
375 ArchiveWorkerThread(ArchiveWorkers* pool);
376 const char* type_name() const override { return "Archive Worker Thread"; }
377 void run() override;
378 };
379
380 // Special archive workers. The goal for this implementation is to startup fast,
381 // distribute spiky workloads efficiently, and shutdown immediately after use.
382 // This makes the implementation quite different from the normal GC worker pool.
383 class ArchiveWorkers : public StackObj {
384 friend class ArchiveWorkerThread;
385 private:
386 // Target number of chunks per worker. This should be large enough to even
387 // out work imbalance, and small enough to keep bookkeeping overheads low.
388 static constexpr int CHUNKS_PER_WORKER = 4;
389 static int max_workers();
390
391 Semaphore _end_semaphore;
392
393 int _num_workers;
394 int _started_workers;
395 int _finish_tokens;
396
397 typedef enum { UNUSED, WORKING, SHUTDOWN } State;
398 volatile State _state;
399
400 ArchiveWorkerTask* _task;
401
402 void run_as_worker();
403 void start_worker_if_needed();
404
405 void run_task_single(ArchiveWorkerTask* task);
406 void run_task_multi(ArchiveWorkerTask* task);
407
408 bool is_parallel();
409
410 public:
411 ArchiveWorkers();
412 ~ArchiveWorkers();
413 void run_task(ArchiveWorkerTask* task);
414 };
415
416 #endif // SHARE_CDS_ARCHIVEUTILS_HPP