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