1 /*
2 * Copyright (c) 2023, 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 "precompiled.hpp"
26 #include "cds/archiveHeapWriter.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/filemap.hpp"
29 #include "cds/heapShared.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "memory/iterator.inline.hpp"
33 #include "memory/oopFactory.hpp"
34 #include "memory/universe.hpp"
35 #include "oops/compressedOops.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/objArrayOop.inline.hpp"
38 #include "oops/oopHandle.inline.hpp"
39 #include "oops/typeArrayKlass.hpp"
40 #include "oops/typeArrayOop.hpp"
41 #include "runtime/java.hpp"
42 #include "runtime/mutexLocker.hpp"
43 #include "utilities/bitMap.inline.hpp"
44
45 #if INCLUDE_G1GC
46 #include "gc/g1/g1CollectedHeap.hpp"
47 #include "gc/g1/heapRegion.hpp"
48 #endif
49
50 #if INCLUDE_CDS_JAVA_HEAP
51
52 GrowableArrayCHeap<u1, mtClassShared>* ArchiveHeapWriter::_buffer = nullptr;
53
54 // The following are offsets from buffer_bottom()
55 size_t ArchiveHeapWriter::_buffer_used;
56 size_t ArchiveHeapWriter::_heap_roots_offset;
57
58 size_t ArchiveHeapWriter::_heap_roots_word_size;
59
60 address ArchiveHeapWriter::_requested_bottom;
61 address ArchiveHeapWriter::_requested_top;
62
63 GrowableArrayCHeap<ArchiveHeapWriter::NativePointerInfo, mtClassShared>* ArchiveHeapWriter::_native_pointers;
64 GrowableArrayCHeap<oop, mtClassShared>* ArchiveHeapWriter::_source_objs;
65
66 ArchiveHeapWriter::BufferOffsetToSourceObjectTable*
67 ArchiveHeapWriter::_buffer_offset_to_source_obj_table = nullptr;
68
69
70 typedef ResourceHashtable<address, size_t,
71 127, // prime number
72 AnyObj::C_HEAP,
73 mtClassShared> FillersTable;
74 static FillersTable* _fillers;
75
76 void ArchiveHeapWriter::init() {
77 if (HeapShared::can_write()) {
78 Universe::heap()->collect(GCCause::_java_lang_system_gc);
79
80 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable();
81 _fillers = new FillersTable();
82 _requested_bottom = nullptr;
83 _requested_top = nullptr;
84
85 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048);
86 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
87
88 guarantee(UseG1GC, "implementation limitation");
89 guarantee(MIN_GC_REGION_ALIGNMENT <= /*G1*/HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
90 }
91 }
92
93 void ArchiveHeapWriter::add_source_obj(oop src_obj) {
94 _source_objs->append(src_obj);
95 }
96
97 void ArchiveHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots,
98 ArchiveHeapInfo* heap_info) {
99 assert(HeapShared::can_write(), "sanity");
100 allocate_buffer();
101 copy_source_objs_to_buffer(roots);
102 set_requested_address(heap_info);
103 relocate_embedded_oops(roots, heap_info);
104 }
105
106 bool ArchiveHeapWriter::is_too_large_to_archive(oop o) {
107 return is_too_large_to_archive(o->size());
108 }
109
110 bool ArchiveHeapWriter::is_string_too_large_to_archive(oop string) {
111 typeArrayOop value = java_lang_String::value_no_keepalive(string);
112 return is_too_large_to_archive(value);
113 }
114
115 bool ArchiveHeapWriter::is_too_large_to_archive(size_t size) {
116 assert(size > 0, "no zero-size object");
117 assert(size * HeapWordSize > size, "no overflow");
118 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive");
119
120 size_t byte_size = size * HeapWordSize;
121 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) {
122 return true;
123 } else {
124 return false;
125 }
126 }
127
128 // Various lookup functions between source_obj, buffered_obj and requested_obj
129 bool ArchiveHeapWriter::is_in_requested_range(oop o) {
130 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized");
131 address a = cast_from_oop<address>(o);
132 return (_requested_bottom <= a && a < _requested_top);
133 }
134
135 oop ArchiveHeapWriter::requested_obj_from_buffer_offset(size_t offset) {
136 oop req_obj = cast_to_oop(_requested_bottom + offset);
137 assert(is_in_requested_range(req_obj), "must be");
138 return req_obj;
139 }
140
141 oop ArchiveHeapWriter::source_obj_to_requested_obj(oop src_obj) {
142 assert(CDSConfig::is_dumping_heap(), "dump-time only");
143 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
144 if (p != nullptr) {
145 return requested_obj_from_buffer_offset(p->buffer_offset());
146 } else {
147 return nullptr;
148 }
149 }
150
151 oop ArchiveHeapWriter::buffered_addr_to_source_obj(address buffered_addr) {
152 oop* p = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr));
153 if (p != nullptr) {
154 return *p;
155 } else {
156 return nullptr;
157 }
158 }
159
160 address ArchiveHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) {
161 return _requested_bottom + buffered_address_to_offset(buffered_addr);
162 }
163
164 oop ArchiveHeapWriter::heap_roots_requested_address() {
165 return cast_to_oop(_requested_bottom + _heap_roots_offset);
166 }
167
168 address ArchiveHeapWriter::requested_address() {
169 assert(_buffer != nullptr, "must be initialized");
170 return _requested_bottom;
171 }
172
173 void ArchiveHeapWriter::allocate_buffer() {
174 int initial_buffer_size = 100000;
175 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size);
176 _buffer_used = 0;
177 ensure_buffer_space(1); // so that buffer_bottom() works
178 }
179
180 void ArchiveHeapWriter::ensure_buffer_space(size_t min_bytes) {
181 // We usually have very small heaps. If we get a huge one it's probably caused by a bug.
182 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects");
183 _buffer->at_grow(to_array_index(min_bytes));
184 }
185
186 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
187 Klass* k = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
188 int length = roots->length();
189 _heap_roots_word_size = objArrayOopDesc::object_size(length);
190 size_t byte_size = _heap_roots_word_size * HeapWordSize;
191 if (byte_size >= MIN_GC_REGION_ALIGNMENT) {
192 log_error(cds, heap)("roots array is too large. Please reduce the number of classes");
193 vm_exit(1);
194 }
195
196 maybe_fill_gc_region_gap(byte_size);
197
198 size_t new_used = _buffer_used + byte_size;
199 ensure_buffer_space(new_used);
200
201 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
202 memset(mem, 0, byte_size);
203 {
204 // This is copied from MemAllocator::finish
205 oopDesc::set_mark(mem, markWord::prototype());
206 oopDesc::release_set_klass(mem, k);
207 }
208 {
209 // This is copied from ObjArrayAllocator::initialize
210 arrayOopDesc::set_length(mem, length);
211 }
212
213 objArrayOop arrayOop = objArrayOop(cast_to_oop(mem));
214 for (int i = 0; i < length; i++) {
215 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside of the real heap!
216 oop o = roots->at(i);
217 if (UseCompressedOops) {
218 * arrayOop->obj_at_addr<narrowOop>(i) = CompressedOops::encode(o);
219 } else {
220 * arrayOop->obj_at_addr<oop>(i) = o;
221 }
222 }
223 log_info(cds, heap)("archived obj roots[%d] = " SIZE_FORMAT " bytes, klass = %p, obj = %p", length, byte_size, k, mem);
224
225 _heap_roots_offset = _buffer_used;
226 _buffer_used = new_used;
227 }
228
229 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
230 for (int i = 0; i < _source_objs->length(); i++) {
231 oop src_obj = _source_objs->at(i);
232 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
233 assert(info != nullptr, "must be");
234 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
235 info->set_buffer_offset(buffer_offset);
236
237 _buffer_offset_to_source_obj_table->put(buffer_offset, src_obj);
238 }
239
240 copy_roots_to_buffer(roots);
241
242 log_info(cds)("Size of heap region = " SIZE_FORMAT " bytes, %d objects, %d roots",
243 _buffer_used, _source_objs->length() + 1, roots->length());
244 }
245
246 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
247 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
248 return byte_size;
249 }
250
251 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
252 assert(is_object_aligned(fill_bytes), "must be");
253 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
254
255 int initial_length = to_array_length(fill_bytes / elemSize);
256 for (int length = initial_length; length >= 0; length --) {
257 size_t array_byte_size = filler_array_byte_size(length);
258 if (array_byte_size == fill_bytes) {
259 return length;
260 }
261 }
262
263 ShouldNotReachHere();
264 return -1;
265 }
266
267 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
268 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
269 Klass* oak = Universe::objectArrayKlassObj(); // already relocated to point to archived klass
270 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
271 memset(mem, 0, fill_bytes);
272 oopDesc::set_mark(mem, markWord::prototype());
273 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
274 cast_to_oop(mem)->set_narrow_klass(nk);
275 arrayOopDesc::set_length(mem, array_length);
276 return mem;
277 }
278
279 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
280 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
281 // leftover space is smaller than a zero-sized array object). Therefore, we need to
282 // make sure there's enough space of min_filler_byte_size in the current region after
283 // required_byte_size has been allocated. If not, fill the remainder of the current
284 // region.
285 size_t min_filler_byte_size = filler_array_byte_size(0);
286 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
287
288 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
289 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
290
291 if (cur_min_region_bottom != next_min_region_bottom) {
292 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
293 // we can map the region in any region-based collector.
294 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
295 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
296 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
297
298 const size_t filler_end = next_min_region_bottom;
299 const size_t fill_bytes = filler_end - _buffer_used;
300 assert(fill_bytes > 0, "must be");
301 ensure_buffer_space(filler_end);
302
303 int array_length = filler_array_length(fill_bytes);
304 log_info(cds, heap)("Inserting filler obj array of %d elements (" SIZE_FORMAT " bytes total) @ buffer offset " SIZE_FORMAT,
305 array_length, fill_bytes, _buffer_used);
306 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
307 _buffer_used = filler_end;
308 _fillers->put((address)filler, fill_bytes);
309 }
310 }
311
312 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
313 size_t* p = _fillers->get(buffered_addr);
314 if (p != nullptr) {
315 assert(*p > 0, "filler must be larger than zero bytes");
316 return *p;
317 } else {
318 return 0; // buffered_addr is not a filler
319 }
320 }
321
322 template <typename T>
323 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
324 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
325 *field_addr = value;
326 }
327
328 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
329 assert(!is_too_large_to_archive(src_obj), "already checked");
330 size_t byte_size = src_obj->size() * HeapWordSize;
331 assert(byte_size > 0, "no zero-size objects");
332
333 // For region-based collectors such as G1, the archive heap may be mapped into
334 // multiple regions. We need to make sure that we don't have an object that can possible
335 // span across two regions.
336 maybe_fill_gc_region_gap(byte_size);
337
338 size_t new_used = _buffer_used + byte_size;
339 assert(new_used > _buffer_used, "no wrap around");
340
341 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
342 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
343 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
344
345 ensure_buffer_space(new_used);
346
347 address from = cast_from_oop<address>(src_obj);
348 address to = offset_to_buffered_address<address>(_buffer_used);
349 assert(is_object_aligned(_buffer_used), "sanity");
350 assert(is_object_aligned(byte_size), "sanity");
351 memcpy(to, from, byte_size);
352
353 // These native pointers will be restored explicitly at run time.
354 if (java_lang_Module::is_instance(src_obj)) {
355 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
356 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
357 #ifdef ASSERT
358 // We only archive these loaders
359 if (src_obj != SystemDictionary::java_platform_loader() &&
360 src_obj != SystemDictionary::java_system_loader()) {
361 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
362 }
363 #endif
364 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
365 }
366
367 size_t buffered_obj_offset = _buffer_used;
368 _buffer_used = new_used;
369
370 return buffered_obj_offset;
371 }
372
373 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
374 assert(!info->is_used(), "only set once");
375 assert(UseG1GC, "must be");
376 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
377 log_info(cds, heap)("Heap end = %p", heap_end);
378
379 size_t heap_region_byte_size = _buffer_used;
380 assert(heap_region_byte_size > 0, "must archived at least one object!");
381
382
383 if (UseCompressedOops) {
384 _requested_bottom = align_down(heap_end - heap_region_byte_size, HeapRegion::GrainBytes);
385 } else {
386 // We always write the objects as if the heap started at this address. This
387 // makes the contents of the archive heap deterministic.
388 //
389 // Note that at runtime, the heap address is selected by the OS, so the archive
390 // heap will not be mapped at 0x10000000, and the contents need to be patched.
391 _requested_bottom = (address)NOCOOPS_REQUESTED_BASE;
392 }
393
394 assert(is_aligned(_requested_bottom, HeapRegion::GrainBytes), "sanity");
395
396 _requested_top = _requested_bottom + _buffer_used;
397
398 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
399 offset_to_buffered_address<HeapWord*>(_buffer_used)));
400 info->set_heap_roots_offset(_heap_roots_offset);
401 }
402
403 // Oop relocation
404
405 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
406 assert(is_in_requested_range(cast_to_oop(p)), "must be");
407
408 address addr = address(p);
409 assert(addr >= _requested_bottom, "must be");
410 size_t offset = addr - _requested_bottom;
411 return offset_to_buffered_address<T*>(offset);
412 }
413
414 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
415 oop o = load_oop_from_buffer(buffered_addr);
416 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
417 return o;
418 }
419
420 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
421 oop request_oop) {
422 assert(is_in_requested_range(request_oop), "must be");
423 store_oop_in_buffer(buffered_addr, request_oop);
424 }
425
426 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
427 *buffered_addr = requested_obj;
428 }
429
430 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
431 narrowOop val = CompressedOops::encode_not_null(requested_obj);
432 *buffered_addr = val;
433 }
434
435 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
436 return *buffered_addr;
437 }
438
439 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
440 return CompressedOops::decode(*buffered_addr);
441 }
442
443 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
444 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
445 if (!CompressedOops::is_null(source_referent)) {
446 oop request_referent = source_obj_to_requested_obj(source_referent);
447 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
448 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
449 }
450 }
451
452 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
453 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
454 address requested_region_bottom;
455
456 assert(request_p >= (T*)_requested_bottom, "sanity");
457 assert(request_p < (T*)_requested_top, "sanity");
458 requested_region_bottom = _requested_bottom;
459
460 // Mark the pointer in the oopmap
461 T* region_bottom = (T*)requested_region_bottom;
462 assert(request_p >= region_bottom, "must be");
463 BitMap::idx_t idx = request_p - region_bottom;
464 assert(idx < oopmap->size(), "overflow");
465 oopmap->set_bit(idx);
466 }
467
468 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
469 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
470 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
471 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
472
473 oop fake_oop = cast_to_oop(buffered_addr);
474 fake_oop->set_narrow_klass(nk);
475
476 // We need to retain the identity_hash, because it may have been used by some hashtables
477 // in the shared heap. This also has the side effect of pre-initializing the
478 // identity_hash for all shared objects, so they are less likely to be written
479 // into during run time, increasing the potential of memory sharing.
480 if (src_obj != nullptr) {
481 intptr_t src_hash = src_obj->identity_hash();
482 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
483 assert(fake_oop->mark().is_unlocked(), "sanity");
484
485 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
486 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
487 }
488 }
489
490 // Relocate an element in the buffered copy of HeapShared::roots()
491 template <typename T> void ArchiveHeapWriter::relocate_root_at(oop requested_roots, int index, CHeapBitMap* oopmap) {
492 size_t offset = (size_t)((objArrayOop)requested_roots)->obj_at_offset<T>(index);
493 relocate_field_in_buffer<T>((T*)(buffered_heap_roots_addr() + offset), oopmap);
494 }
495
496 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
497 oop _src_obj;
498 address _buffered_obj;
499 CHeapBitMap* _oopmap;
500
501 public:
502 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
503 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) {}
504
505 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
506 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
507
508 private:
509 template <class T> void do_oop_work(T *p) {
510 size_t field_offset = pointer_delta(p, _src_obj, sizeof(char));
511 ArchiveHeapWriter::relocate_field_in_buffer<T>((T*)(_buffered_obj + field_offset), _oopmap);
512 }
513 };
514
515 // Update all oop fields embedded in the buffered objects
516 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
517 ArchiveHeapInfo* heap_info) {
518 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
519 size_t heap_region_byte_size = _buffer_used;
520 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
521
522 auto iterator = [&] (oop src_obj, HeapShared::CachedOopInfo& info) {
523 oop requested_obj = requested_obj_from_buffer_offset(info.buffer_offset());
524 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
525 address buffered_obj = offset_to_buffered_address<address>(info.buffer_offset());
526 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
527 src_obj->oop_iterate(&relocator);
528 };
529 HeapShared::archived_object_cache()->iterate_all(iterator);
530
531 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
532 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
533 oop requested_roots = requested_obj_from_buffer_offset(_heap_roots_offset);
534 update_header_for_requested_obj(requested_roots, nullptr, Universe::objectArrayKlassObj());
535 int length = roots != nullptr ? roots->length() : 0;
536 for (int i = 0; i < length; i++) {
537 if (UseCompressedOops) {
538 relocate_root_at<narrowOop>(requested_roots, i, heap_info->oopmap());
539 } else {
540 relocate_root_at<oop>(requested_roots, i, heap_info->oopmap());
541 }
542 }
543
544 compute_ptrmap(heap_info);
545 }
546
547 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
548 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
549 if (ptr != nullptr) {
550 NativePointerInfo info;
551 info._src_obj = src_obj;
552 info._field_offset = field_offset;
553 _native_pointers->append(info);
554 }
555 }
556
557 // Do we have a jlong/jint field that's actually a pointer to a MetaspaceObj?
558 bool ArchiveHeapWriter::is_marked_as_native_pointer(ArchiveHeapInfo* heap_info, oop src_obj, int field_offset) {
559 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
560 assert(p != nullptr, "must be");
561
562 // requested_field_addr = the address of this field in the requested space
563 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
564 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
565 assert((Metadata**)_requested_bottom <= requested_field_addr && requested_field_addr < (Metadata**) _requested_top, "range check");
566
567 BitMap::idx_t idx = requested_field_addr - (Metadata**) _requested_bottom;
568 return (idx < heap_info->ptrmap()->size()) && (heap_info->ptrmap()->at(idx) == true);
569 }
570
571 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
572 int num_non_null_ptrs = 0;
573 Metadata** bottom = (Metadata**) _requested_bottom;
574 Metadata** top = (Metadata**) _requested_top; // exclusive
575 heap_info->ptrmap()->resize(top - bottom);
576
577 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
578 for (int i = 0; i < _native_pointers->length(); i++) {
579 NativePointerInfo info = _native_pointers->at(i);
580 oop src_obj = info._src_obj;
581 int field_offset = info._field_offset;
582 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
583 // requested_field_addr = the address of this field in the requested space
584 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
585 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
586 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
587
588 // Mark this field in the bitmap
589 BitMap::idx_t idx = requested_field_addr - bottom;
590 heap_info->ptrmap()->set_bit(idx);
591 num_non_null_ptrs ++;
592 max_idx = MAX2(max_idx, idx);
593
594 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
595 // this address if the RO/RW regions are mapped at the default location).
596
597 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
598 Metadata* native_ptr = *buffered_field_addr;
599 assert(native_ptr != nullptr, "sanity");
600
601 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
602 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
603 *buffered_field_addr = (Metadata*)requested_native_ptr;
604 }
605
606 heap_info->ptrmap()->resize(max_idx + 1);
607 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (" SIZE_FORMAT " bits)",
608 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
609 }
610
611 #endif // INCLUDE_CDS_JAVA_HEAP
--- EOF ---