1 /*
2 * Copyright (c) 2023, 2025, 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.
22 *
23 */
24
25 #include "cds/aotReferenceObjSupport.hpp"
26 #include "cds/archiveHeapWriter.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/filemap.hpp"
29 #include "cds/heapShared.hpp"
30 #include "cds/regeneratedClasses.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/modules.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "gc/shared/collectedHeap.hpp"
35 #include "memory/iterator.inline.hpp"
36 #include "memory/oopFactory.hpp"
37 #include "memory/universe.hpp"
38 #include "oops/compressedOops.hpp"
39 #include "oops/objArrayOop.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "oops/oopHandle.inline.hpp"
42 #include "oops/typeArrayKlass.hpp"
43 #include "oops/typeArrayOop.hpp"
44 #include "runtime/java.hpp"
45 #include "runtime/mutexLocker.hpp"
46 #include "utilities/bitMap.inline.hpp"
47 #if INCLUDE_G1GC
48 #include "gc/g1/g1CollectedHeap.hpp"
49 #include "gc/g1/g1HeapRegion.hpp"
50 #endif
51
52 #if INCLUDE_CDS_JAVA_HEAP
53
54 GrowableArrayCHeap<u1, mtClassShared>* ArchiveHeapWriter::_buffer = nullptr;
55
56 // The following are offsets from buffer_bottom()
57 size_t ArchiveHeapWriter::_buffer_used;
58
59 // Heap root segments
60 HeapRootSegments ArchiveHeapWriter::_heap_root_segments;
61
62 address ArchiveHeapWriter::_requested_bottom;
63 address ArchiveHeapWriter::_requested_top;
64
65 GrowableArrayCHeap<ArchiveHeapWriter::NativePointerInfo, mtClassShared>* ArchiveHeapWriter::_native_pointers;
66 GrowableArrayCHeap<oop, mtClassShared>* ArchiveHeapWriter::_source_objs;
67 GrowableArrayCHeap<ArchiveHeapWriter::HeapObjOrder, mtClassShared>* ArchiveHeapWriter::_source_objs_order;
68
69 ArchiveHeapWriter::BufferOffsetToSourceObjectTable*
70 ArchiveHeapWriter::_buffer_offset_to_source_obj_table = nullptr;
71
72
73 typedef HashTable<
74 size_t, // offset of a filler from ArchiveHeapWriter::buffer_bottom()
75 size_t, // size of this filler (in bytes)
76 127, // prime number
77 AnyObj::C_HEAP,
78 mtClassShared> FillersTable;
79 static FillersTable* _fillers;
80 static int _num_native_ptrs = 0;
81
82 void ArchiveHeapWriter::init() {
83 if (CDSConfig::is_dumping_heap()) {
84 Universe::heap()->collect(GCCause::_java_lang_system_gc);
85
86 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M);
87 _fillers = new FillersTable();
88 _requested_bottom = nullptr;
89 _requested_top = nullptr;
90
91 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048);
92 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
93
94 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
95 }
96 }
97
98 void ArchiveHeapWriter::delete_tables_with_raw_oops() {
99 delete _source_objs;
100 _source_objs = nullptr;
101 }
102
103 void ArchiveHeapWriter::add_source_obj(oop src_obj) {
104 _source_objs->append(src_obj);
105 }
106
107 void ArchiveHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots,
108 ArchiveHeapInfo* heap_info) {
109 assert(CDSConfig::is_dumping_heap(), "sanity");
110 allocate_buffer();
111 copy_source_objs_to_buffer(roots);
112 set_requested_address(heap_info);
113 relocate_embedded_oops(roots, heap_info);
114 }
115
116 bool ArchiveHeapWriter::is_too_large_to_archive(oop o) {
117 return is_too_large_to_archive(o->size());
118 }
119
120 bool ArchiveHeapWriter::is_string_too_large_to_archive(oop string) {
121 typeArrayOop value = java_lang_String::value_no_keepalive(string);
122 return is_too_large_to_archive(value);
123 }
124
125 bool ArchiveHeapWriter::is_too_large_to_archive(size_t size) {
126 assert(size > 0, "no zero-size object");
127 assert(size * HeapWordSize > size, "no overflow");
128 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive");
129
130 size_t byte_size = size * HeapWordSize;
131 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) {
132 return true;
133 } else {
134 return false;
135 }
136 }
137
138 // Various lookup functions between source_obj, buffered_obj and requested_obj
139 bool ArchiveHeapWriter::is_in_requested_range(oop o) {
140 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized");
141 address a = cast_from_oop<address>(o);
142 return (_requested_bottom <= a && a < _requested_top);
143 }
144
145 oop ArchiveHeapWriter::requested_obj_from_buffer_offset(size_t offset) {
146 oop req_obj = cast_to_oop(_requested_bottom + offset);
147 assert(is_in_requested_range(req_obj), "must be");
148 return req_obj;
149 }
150
151 oop ArchiveHeapWriter::source_obj_to_requested_obj(oop src_obj) {
152 assert(CDSConfig::is_dumping_heap(), "dump-time only");
153 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj);
154 if (p != nullptr) {
155 return requested_obj_from_buffer_offset(p->buffer_offset());
156 } else {
157 return nullptr;
158 }
159 }
160
161 oop ArchiveHeapWriter::buffered_addr_to_source_obj(address buffered_addr) {
162 OopHandle* oh = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr));
163 if (oh != nullptr) {
164 return oh->resolve();
165 } else {
166 return nullptr;
167 }
168 }
169
170 Klass* ArchiveHeapWriter::real_klass_of_buffered_oop(address buffered_addr) {
171 oop p = buffered_addr_to_source_obj(buffered_addr);
172 if (p != nullptr) {
173 return p->klass();
174 } else if (get_filler_size_at(buffered_addr) > 0) {
175 return Universe::fillerArrayKlass();
176 } else {
177 // This is one of the root segments
178 return Universe::objectArrayKlass();
179 }
180 }
181
182 size_t ArchiveHeapWriter::size_of_buffered_oop(address buffered_addr) {
183 oop p = buffered_addr_to_source_obj(buffered_addr);
184 if (p != nullptr) {
185 return p->size();
186 }
187
188 size_t nbytes = get_filler_size_at(buffered_addr);
189 if (nbytes > 0) {
190 assert((nbytes % BytesPerWord) == 0, "should be aligned");
191 return nbytes / BytesPerWord;
192 }
193
194 address hrs = buffer_bottom();
195 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
196 nbytes = _heap_root_segments.size_in_bytes(seg_idx);
197 if (hrs == buffered_addr) {
198 assert((nbytes % BytesPerWord) == 0, "should be aligned");
199 return nbytes / BytesPerWord;
200 }
201 hrs += nbytes;
202 }
203
204 ShouldNotReachHere();
205 return 0;
206 }
207
208 address ArchiveHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) {
209 return _requested_bottom + buffered_address_to_offset(buffered_addr);
210 }
211
212 address ArchiveHeapWriter::requested_address() {
213 assert(_buffer != nullptr, "must be initialized");
214 return _requested_bottom;
215 }
216
217 void ArchiveHeapWriter::allocate_buffer() {
218 int initial_buffer_size = 100000;
219 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size);
220 _buffer_used = 0;
221 ensure_buffer_space(1); // so that buffer_bottom() works
222 }
223
224 void ArchiveHeapWriter::ensure_buffer_space(size_t min_bytes) {
225 // We usually have very small heaps. If we get a huge one it's probably caused by a bug.
226 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects");
227 _buffer->at_grow(to_array_index(min_bytes));
228 }
229
230 objArrayOop ArchiveHeapWriter::allocate_root_segment(size_t offset, int element_count) {
231 HeapWord* mem = offset_to_buffered_address<HeapWord *>(offset);
232 memset(mem, 0, objArrayOopDesc::object_size(element_count));
233
234 // The initialization code is copied from MemAllocator::finish and ObjArrayAllocator::initialize.
235 if (UseCompactObjectHeaders) {
236 oopDesc::release_set_mark(mem, Universe::objectArrayKlass()->prototype_header());
237 } else {
238 oopDesc::set_mark(mem, markWord::prototype());
239 oopDesc::release_set_klass(mem, Universe::objectArrayKlass());
240 }
241 arrayOopDesc::set_length(mem, element_count);
242 return objArrayOop(cast_to_oop(mem));
243 }
244
245 void ArchiveHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) {
246 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap!
247 if (UseCompressedOops) {
248 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root);
249 } else {
250 *segment->obj_at_addr<oop>(index) = root;
251 }
252 }
253
254 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
255 // Depending on the number of classes we are archiving, a single roots array may be
256 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which
257 // allows us to chop the large array into a series of "segments". Current layout
258 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end
259 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT.
260 // This is simple and efficient. We do not need filler objects anywhere between the segments,
261 // or immediately after the last segment. This allows starting the object dump immediately
262 // after the roots.
263
264 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0,
265 "Pre-condition: Roots start at aligned boundary: %zu", _buffer_used);
266
267 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize);
268 assert(objArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT,
269 "Should match exactly");
270
271 HeapRootSegments segments(_buffer_used,
272 roots->length(),
273 MIN_GC_REGION_ALIGNMENT,
274 max_elem_count);
275
276 int root_index = 0;
277 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) {
278 int size_elems = segments.size_in_elems(seg_idx);
279 size_t size_bytes = segments.size_in_bytes(seg_idx);
280
281 size_t oop_offset = _buffer_used;
282 _buffer_used = oop_offset + size_bytes;
283 ensure_buffer_space(_buffer_used);
284
285 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0,
286 "Roots segment %zu start is not aligned: %zu",
287 segments.count(), oop_offset);
288
289 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems);
290 for (int i = 0; i < size_elems; i++) {
291 root_segment_at_put(seg_oop, i, roots->at(root_index++));
292 }
293
294 log_info(aot, heap)("archived obj root segment [%d] = %zu bytes, obj = " PTR_FORMAT,
295 size_elems, size_bytes, p2i(seg_oop));
296 }
297
298 assert(root_index == roots->length(), "Post-condition: All roots are handled");
299
300 _heap_root_segments = segments;
301 }
302
303 // The goal is to sort the objects in increasing order of:
304 // - objects that have only oop pointers
305 // - objects that have both native and oop pointers
306 // - objects that have only native pointers
307 // - objects that have no pointers
308 static int oop_sorting_rank(oop o) {
309 bool has_oop_ptr, has_native_ptr;
310 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
311
312 if (has_oop_ptr) {
313 if (!has_native_ptr) {
314 return 0;
315 } else {
316 return 1;
317 }
318 } else {
319 if (has_native_ptr) {
320 return 2;
321 } else {
322 return 3;
323 }
324 }
325 }
326
327 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
328 int rank_a = a->_rank;
329 int rank_b = b->_rank;
330
331 if (rank_a != rank_b) {
332 return rank_a - rank_b;
333 } else {
334 // If they are the same rank, sort them by their position in the _source_objs array
335 return a->_index - b->_index;
336 }
337 }
338
339 void ArchiveHeapWriter::sort_source_objs() {
340 log_info(aot)("sorting heap objects");
341 int len = _source_objs->length();
342 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
343
344 for (int i = 0; i < len; i++) {
345 oop o = _source_objs->at(i);
346 int rank = oop_sorting_rank(o);
347 HeapObjOrder os = {i, rank};
348 _source_objs_order->append(os);
349 }
350 log_info(aot)("computed ranks");
351 _source_objs_order->sort(compare_objs_by_oop_fields);
352 log_info(aot)("sorting heap objects done");
353 }
354
355 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
356 // There could be multiple root segments, which we want to be aligned by region.
357 // Putting them ahead of objects makes sure we waste no space.
358 copy_roots_to_buffer(roots);
359
360 sort_source_objs();
361 for (int i = 0; i < _source_objs_order->length(); i++) {
362 int src_obj_index = _source_objs_order->at(i)._index;
363 oop src_obj = _source_objs->at(src_obj_index);
364 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj);
365 assert(info != nullptr, "must be");
366 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
367 info->set_buffer_offset(buffer_offset);
368
369 OopHandle handle(Universe::vm_global(), src_obj);
370 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, handle);
371 _buffer_offset_to_source_obj_table->maybe_grow();
372
373 if (java_lang_Module::is_instance(src_obj)) {
374 Modules::check_archived_module_oop(src_obj);
375 }
376 }
377
378 log_info(aot)("Size of heap region = %zu bytes, %d objects, %d roots, %d native ptrs",
379 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
380 }
381
382 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
383 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
384 return byte_size;
385 }
386
387 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
388 assert(is_object_aligned(fill_bytes), "must be");
389 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
390
391 int initial_length = to_array_length(fill_bytes / elemSize);
392 for (int length = initial_length; length >= 0; length --) {
393 size_t array_byte_size = filler_array_byte_size(length);
394 if (array_byte_size == fill_bytes) {
395 return length;
396 }
397 }
398
399 ShouldNotReachHere();
400 return -1;
401 }
402
403 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
404 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
405 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
406 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
407 memset(mem, 0, fill_bytes);
408 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
409 if (UseCompactObjectHeaders) {
410 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk));
411 } else {
412 oopDesc::set_mark(mem, markWord::prototype());
413 cast_to_oop(mem)->set_narrow_klass(nk);
414 }
415 arrayOopDesc::set_length(mem, array_length);
416 return mem;
417 }
418
419 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
420 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
421 // leftover space is smaller than a zero-sized array object). Therefore, we need to
422 // make sure there's enough space of min_filler_byte_size in the current region after
423 // required_byte_size has been allocated. If not, fill the remainder of the current
424 // region.
425 size_t min_filler_byte_size = filler_array_byte_size(0);
426 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
427
428 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
429 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
430
431 if (cur_min_region_bottom != next_min_region_bottom) {
432 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
433 // we can map the region in any region-based collector.
434 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
435 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
436 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
437
438 const size_t filler_end = next_min_region_bottom;
439 const size_t fill_bytes = filler_end - _buffer_used;
440 assert(fill_bytes > 0, "must be");
441 ensure_buffer_space(filler_end);
442
443 int array_length = filler_array_length(fill_bytes);
444 log_info(aot, heap)("Inserting filler obj array of %d elements (%zu bytes total) @ buffer offset %zu",
445 array_length, fill_bytes, _buffer_used);
446 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
447 _buffer_used = filler_end;
448 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
449 }
450 }
451
452 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
453 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
454 if (p != nullptr) {
455 assert(*p > 0, "filler must be larger than zero bytes");
456 return *p;
457 } else {
458 return 0; // buffered_addr is not a filler
459 }
460 }
461
462 template <typename T>
463 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
464 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
465 *field_addr = value;
466 }
467
468 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
469 assert(!is_too_large_to_archive(src_obj), "already checked");
470 size_t byte_size = src_obj->size() * HeapWordSize;
471 assert(byte_size > 0, "no zero-size objects");
472
473 // For region-based collectors such as G1, the archive heap may be mapped into
474 // multiple regions. We need to make sure that we don't have an object that can possible
475 // span across two regions.
476 maybe_fill_gc_region_gap(byte_size);
477
478 size_t new_used = _buffer_used + byte_size;
479 assert(new_used > _buffer_used, "no wrap around");
480
481 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
482 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
483 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
484
485 ensure_buffer_space(new_used);
486
487 address from = cast_from_oop<address>(src_obj);
488 address to = offset_to_buffered_address<address>(_buffer_used);
489 assert(is_object_aligned(_buffer_used), "sanity");
490 assert(is_object_aligned(byte_size), "sanity");
491 memcpy(to, from, byte_size);
492
493 // These native pointers will be restored explicitly at run time.
494 if (java_lang_Module::is_instance(src_obj)) {
495 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
496 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
497 #ifdef ASSERT
498 // We only archive these loaders
499 if (src_obj != SystemDictionary::java_platform_loader() &&
500 src_obj != SystemDictionary::java_system_loader()) {
501 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
502 }
503 #endif
504 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
505 }
506
507 size_t buffered_obj_offset = _buffer_used;
508 _buffer_used = new_used;
509
510 return buffered_obj_offset;
511 }
512
513 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
514 assert(!info->is_used(), "only set once");
515
516 size_t heap_region_byte_size = _buffer_used;
517 assert(heap_region_byte_size > 0, "must archived at least one object!");
518
519 if (UseCompressedOops) {
520 if (UseG1GC) {
521 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
522 log_info(aot, heap)("Heap end = %p", heap_end);
523 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
524 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT);
525 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
526 } else {
527 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT);
528 }
529 } else {
530 // We always write the objects as if the heap started at this address. This
531 // makes the contents of the archive heap deterministic.
532 //
533 // Note that at runtime, the heap address is selected by the OS, so the archive
534 // heap will not be mapped at 0x10000000, and the contents need to be patched.
535 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT);
536 }
537
538 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity");
539
540 _requested_top = _requested_bottom + _buffer_used;
541
542 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
543 offset_to_buffered_address<HeapWord*>(_buffer_used)));
544 info->set_heap_root_segments(_heap_root_segments);
545 }
546
547 // Oop relocation
548
549 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
550 assert(is_in_requested_range(cast_to_oop(p)), "must be");
551
552 address addr = address(p);
553 assert(addr >= _requested_bottom, "must be");
554 size_t offset = addr - _requested_bottom;
555 return offset_to_buffered_address<T*>(offset);
556 }
557
558 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
559 oop o = load_oop_from_buffer(buffered_addr);
560 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
561 return o;
562 }
563
564 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
565 oop request_oop) {
566 assert(is_in_requested_range(request_oop), "must be");
567 store_oop_in_buffer(buffered_addr, request_oop);
568 }
569
570 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
571 *buffered_addr = requested_obj;
572 }
573
574 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
575 narrowOop val = CompressedOops::encode_not_null(requested_obj);
576 *buffered_addr = val;
577 }
578
579 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
580 return *buffered_addr;
581 }
582
583 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
584 return CompressedOops::decode(*buffered_addr);
585 }
586
587 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
588 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
589 if (source_referent != nullptr) {
590 if (java_lang_Class::is_instance(source_referent)) {
591 Klass* k = java_lang_Class::as_Klass(source_referent);
592 if (RegeneratedClasses::has_been_regenerated(k)) {
593 source_referent = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
594 }
595 // When the source object points to a "real" mirror, the buffered object should point
596 // to the "scratch" mirror, which has all unarchivable fields scrubbed (to be reinstated
597 // at run time).
598 source_referent = HeapShared::scratch_java_mirror(source_referent);
599 assert(source_referent != nullptr, "must be");
600 }
601 oop request_referent = source_obj_to_requested_obj(source_referent);
602 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
603 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
604 }
605 }
606
607 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
608 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
609 address requested_region_bottom;
610
611 assert(request_p >= (T*)_requested_bottom, "sanity");
612 assert(request_p < (T*)_requested_top, "sanity");
613 requested_region_bottom = _requested_bottom;
614
615 // Mark the pointer in the oopmap
616 T* region_bottom = (T*)requested_region_bottom;
617 assert(request_p >= region_bottom, "must be");
618 BitMap::idx_t idx = request_p - region_bottom;
619 assert(idx < oopmap->size(), "overflow");
620 oopmap->set_bit(idx);
621 }
622
623 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
624 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
625 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
626 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
627
628 oop fake_oop = cast_to_oop(buffered_addr);
629 if (UseCompactObjectHeaders) {
630 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk));
631 } else {
632 fake_oop->set_narrow_klass(nk);
633 }
634
635 if (src_obj == nullptr) {
636 return;
637 }
638 // We need to retain the identity_hash, because it may have been used by some hashtables
639 // in the shared heap.
640 if (!src_obj->fast_no_hash_check()) {
641 intptr_t src_hash = src_obj->identity_hash();
642 if (UseCompactObjectHeaders) {
643 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
644 } else {
645 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
646 }
647 assert(fake_oop->mark().is_unlocked(), "sanity");
648
649 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
650 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
651 }
652 // Strip age bits.
653 fake_oop->set_mark(fake_oop->mark().set_age(0));
654 }
655
656 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
657 oop _src_obj;
658 address _buffered_obj;
659 CHeapBitMap* _oopmap;
660 bool _is_java_lang_ref;
661 public:
662 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
663 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap)
664 {
665 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(src_obj);
666 }
667
668 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
669 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
670
671 private:
672 template <class T> void do_oop_work(T *p) {
673 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_src_obj));
674 T* field_addr = (T*)(_buffered_obj + field_offset);
675 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
676 // Do not copy these fields. Set them to null
677 *field_addr = (T)0x0;
678 } else {
679 ArchiveHeapWriter::relocate_field_in_buffer<T>(field_addr, _oopmap);
680 }
681 }
682 };
683
684 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
685 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
686 size_t start = bitmap->find_first_set_bit(0);
687 size_t end = bitmap->size();
688 log_info(aot)("%s = %7zu ... %7zu (%3zu%% ... %3zu%% = %3zu%%)", which,
689 start, end,
690 start * 100 / total_bits,
691 end * 100 / total_bits,
692 (end - start) * 100 / total_bits);
693 }
694
695 // Update all oop fields embedded in the buffered objects
696 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
697 ArchiveHeapInfo* heap_info) {
698 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
699 size_t heap_region_byte_size = _buffer_used;
700 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
701
702 for (int i = 0; i < _source_objs_order->length(); i++) {
703 int src_obj_index = _source_objs_order->at(i)._index;
704 oop src_obj = _source_objs->at(src_obj_index);
705 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj);
706 assert(info != nullptr, "must be");
707 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
708 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
709 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
710 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
711 src_obj->oop_iterate(&relocator);
712 };
713
714 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
715 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
716 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
717 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx);
718
719 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset);
720 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass());
721 address buffered_obj = offset_to_buffered_address<address>(seg_offset);
722 int length = _heap_root_segments.size_in_elems(seg_idx);
723
724 if (UseCompressedOops) {
725 for (int i = 0; i < length; i++) {
726 narrowOop* addr = (narrowOop*)(buffered_obj + objArrayOopDesc::obj_at_offset<narrowOop>(i));
727 relocate_field_in_buffer<narrowOop>(addr, heap_info->oopmap());
728 }
729 } else {
730 for (int i = 0; i < length; i++) {
731 oop* addr = (oop*)(buffered_obj + objArrayOopDesc::obj_at_offset<oop>(i));
732 relocate_field_in_buffer<oop>(addr, heap_info->oopmap());
733 }
734 }
735 }
736
737 compute_ptrmap(heap_info);
738
739 size_t total_bytes = (size_t)_buffer->length();
740 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
741 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
742 }
743
744 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
745 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
746 if (ptr != nullptr) {
747 NativePointerInfo info;
748 info._src_obj = src_obj;
749 info._field_offset = field_offset;
750 _native_pointers->append(info);
751 HeapShared::set_has_native_pointers(src_obj);
752 _num_native_ptrs ++;
753 }
754 }
755
756 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
757 int num_non_null_ptrs = 0;
758 Metadata** bottom = (Metadata**) _requested_bottom;
759 Metadata** top = (Metadata**) _requested_top; // exclusive
760 heap_info->ptrmap()->resize(top - bottom);
761
762 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
763 for (int i = 0; i < _native_pointers->length(); i++) {
764 NativePointerInfo info = _native_pointers->at(i);
765 oop src_obj = info._src_obj;
766 int field_offset = info._field_offset;
767 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj);
768 // requested_field_addr = the address of this field in the requested space
769 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
770 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
771 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
772
773 // Mark this field in the bitmap
774 BitMap::idx_t idx = requested_field_addr - bottom;
775 heap_info->ptrmap()->set_bit(idx);
776 num_non_null_ptrs ++;
777 max_idx = MAX2(max_idx, idx);
778
779 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
780 // this address if the RO/RW regions are mapped at the default location).
781
782 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
783 Metadata* native_ptr = *buffered_field_addr;
784 guarantee(native_ptr != nullptr, "sanity");
785
786 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
787 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
788 }
789
790 guarantee(ArchiveBuilder::current()->has_been_archived((address)native_ptr),
791 "Metadata %p should have been archived", native_ptr);
792
793 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
794 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
795 *buffered_field_addr = (Metadata*)requested_native_ptr;
796 }
797
798 heap_info->ptrmap()->resize(max_idx + 1);
799 log_info(aot, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (%zu bits)",
800 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
801 }
802
803 #endif // INCLUDE_CDS_JAVA_HEAP