1 /*
2 * Copyright (c) 2024, 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 #if INCLUDE_G1GC
45 #include "gc/g1/g1CollectedHeap.hpp"
46 #include "gc/g1/g1HeapRegion.hpp"
47 #endif
48
49 #if INCLUDE_CDS_JAVA_HEAP
50
51 GrowableArrayCHeap<u1, mtClassShared>* ArchiveHeapWriter::_buffer = nullptr;
52
53 // The following are offsets from buffer_bottom()
54 size_t ArchiveHeapWriter::_buffer_used;
55 size_t ArchiveHeapWriter::_heap_roots_offset;
56
57 size_t ArchiveHeapWriter::_heap_roots_word_size;
58
59 address ArchiveHeapWriter::_requested_bottom;
60 address ArchiveHeapWriter::_requested_top;
61
62 GrowableArrayCHeap<ArchiveHeapWriter::NativePointerInfo, mtClassShared>* ArchiveHeapWriter::_native_pointers;
63 GrowableArrayCHeap<oop, mtClassShared>* ArchiveHeapWriter::_source_objs;
64 GrowableArrayCHeap<ArchiveHeapWriter::HeapObjOrder, mtClassShared>* ArchiveHeapWriter::_source_objs_order;
65
66 ArchiveHeapWriter::BufferOffsetToSourceObjectTable*
67 ArchiveHeapWriter::_buffer_offset_to_source_obj_table = nullptr;
68
69
70 typedef ResourceHashtable<
71 size_t, // offset of a filler from ArchiveHeapWriter::buffer_bottom()
72 size_t, // size of this filler (in bytes)
73 127, // prime number
74 AnyObj::C_HEAP,
75 mtClassShared> FillersTable;
76 static FillersTable* _fillers;
77 static int _num_native_ptrs = 0;
78
79 void ArchiveHeapWriter::init() {
80 if (HeapShared::can_write()) {
81 Universe::heap()->collect(GCCause::_java_lang_system_gc);
82
83 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M);
84 _fillers = new FillersTable();
85 _requested_bottom = nullptr;
86 _requested_top = nullptr;
87
88 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048);
89 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
90
91 guarantee(UseG1GC, "implementation limitation");
92 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
93 }
94 }
95
96 void ArchiveHeapWriter::add_source_obj(oop src_obj) {
97 _source_objs->append(src_obj);
98 }
99
100 void ArchiveHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots,
101 ArchiveHeapInfo* heap_info) {
102 assert(HeapShared::can_write(), "sanity");
103 allocate_buffer();
104 copy_source_objs_to_buffer(roots);
105 set_requested_address(heap_info);
106 relocate_embedded_oops(roots, heap_info);
107 }
108
109 bool ArchiveHeapWriter::is_too_large_to_archive(oop o) {
110 return is_too_large_to_archive(o->size());
111 }
112
113 bool ArchiveHeapWriter::is_string_too_large_to_archive(oop string) {
114 typeArrayOop value = java_lang_String::value_no_keepalive(string);
115 return is_too_large_to_archive(value);
116 }
117
118 bool ArchiveHeapWriter::is_too_large_to_archive(size_t size) {
119 assert(size > 0, "no zero-size object");
120 assert(size * HeapWordSize > size, "no overflow");
121 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive");
122
123 size_t byte_size = size * HeapWordSize;
124 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) {
125 return true;
126 } else {
127 return false;
128 }
129 }
130
131 // Various lookup functions between source_obj, buffered_obj and requested_obj
132 bool ArchiveHeapWriter::is_in_requested_range(oop o) {
133 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized");
134 address a = cast_from_oop<address>(o);
135 return (_requested_bottom <= a && a < _requested_top);
136 }
137
138 oop ArchiveHeapWriter::requested_obj_from_buffer_offset(size_t offset) {
139 oop req_obj = cast_to_oop(_requested_bottom + offset);
140 assert(is_in_requested_range(req_obj), "must be");
141 return req_obj;
142 }
143
144 oop ArchiveHeapWriter::source_obj_to_requested_obj(oop src_obj) {
145 assert(CDSConfig::is_dumping_heap(), "dump-time only");
146 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
147 if (p != nullptr) {
148 return requested_obj_from_buffer_offset(p->buffer_offset());
149 } else {
150 return nullptr;
151 }
152 }
153
154 oop ArchiveHeapWriter::buffered_addr_to_source_obj(address buffered_addr) {
155 oop* p = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr));
156 if (p != nullptr) {
157 return *p;
158 } else {
159 return nullptr;
160 }
161 }
162
163 address ArchiveHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) {
164 return _requested_bottom + buffered_address_to_offset(buffered_addr);
165 }
166
167 oop ArchiveHeapWriter::heap_roots_requested_address() {
168 return cast_to_oop(_requested_bottom + _heap_roots_offset);
169 }
170
171 address ArchiveHeapWriter::requested_address() {
172 assert(_buffer != nullptr, "must be initialized");
173 return _requested_bottom;
174 }
175
176 void ArchiveHeapWriter::allocate_buffer() {
177 int initial_buffer_size = 100000;
178 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size);
179 _buffer_used = 0;
180 ensure_buffer_space(1); // so that buffer_bottom() works
181 }
182
183 void ArchiveHeapWriter::ensure_buffer_space(size_t min_bytes) {
184 // We usually have very small heaps. If we get a huge one it's probably caused by a bug.
185 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects");
186 _buffer->at_grow(to_array_index(min_bytes));
187 }
188
189 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
190 Klass* k = Universe::objectArrayKlass(); // already relocated to point to archived klass
191 int length = roots->length();
192 _heap_roots_word_size = objArrayOopDesc::object_size(length);
193 size_t byte_size = _heap_roots_word_size * HeapWordSize;
194 if (byte_size >= MIN_GC_REGION_ALIGNMENT) {
195 log_error(cds, heap)("roots array is too large. Please reduce the number of classes");
196 vm_exit(1);
197 }
198
199 maybe_fill_gc_region_gap(byte_size);
200
201 size_t new_used = _buffer_used + byte_size;
202 ensure_buffer_space(new_used);
203
204 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
205 memset(mem, 0, byte_size);
206 {
207 // This is copied from MemAllocator::finish
208 if (UseCompactObjectHeaders) {
209 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(k);
210 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk));
211 } else {
212 oopDesc::set_mark(mem, markWord::prototype());
213 oopDesc::release_set_klass(mem, k);
214 }
215 }
216 {
217 // This is copied from ObjArrayAllocator::initialize
218 arrayOopDesc::set_length(mem, length);
219 }
220
221 objArrayOop arrayOop = objArrayOop(cast_to_oop(mem));
222 for (int i = 0; i < length; i++) {
223 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside of the real heap!
224 oop o = roots->at(i);
225 if (UseCompressedOops) {
226 * arrayOop->obj_at_addr<narrowOop>(i) = CompressedOops::encode(o);
227 } else {
228 * arrayOop->obj_at_addr<oop>(i) = o;
229 }
230 }
231 log_info(cds, heap)("archived obj roots[%d] = " SIZE_FORMAT " bytes, klass = %p, obj = %p", length, byte_size, k, mem);
232
233 _heap_roots_offset = _buffer_used;
234 _buffer_used = new_used;
235 }
236
237 static int oop_sorting_rank(oop o) {
238 bool has_oop_ptr, has_native_ptr;
239 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
240
241 if (!has_oop_ptr) {
242 if (!has_native_ptr) {
243 return 0;
244 } else {
245 return 1;
246 }
247 } else {
248 if (has_native_ptr) {
249 return 2;
250 } else {
251 return 3;
252 }
253 }
254 }
255
256 // The goal is to sort the objects in increasing order of:
257 // - objects that have no pointers
258 // - objects that have only native pointers
259 // - objects that have both native and oop pointers
260 // - objects that have only oop pointers
261 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
262 int rank_a = a->_rank;
263 int rank_b = b->_rank;
264
265 if (rank_a != rank_b) {
266 return rank_a - rank_b;
267 } else {
268 // If they are the same rank, sort them by their position in the _source_objs array
269 return a->_index - b->_index;
270 }
271 }
272
273 void ArchiveHeapWriter::sort_source_objs() {
274 log_info(cds)("sorting heap objects");
275 int len = _source_objs->length();
276 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
277
278 for (int i = 0; i < len; i++) {
279 oop o = _source_objs->at(i);
280 int rank = oop_sorting_rank(o);
281 HeapObjOrder os = {i, rank};
282 _source_objs_order->append(os);
283 }
284 log_info(cds)("computed ranks");
285 _source_objs_order->sort(compare_objs_by_oop_fields);
286 log_info(cds)("sorting heap objects done");
287 }
288
289 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
290 sort_source_objs();
291 for (int i = 0; i < _source_objs_order->length(); i++) {
292 int src_obj_index = _source_objs_order->at(i)._index;
293 oop src_obj = _source_objs->at(src_obj_index);
294 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
295 assert(info != nullptr, "must be");
296 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
297 info->set_buffer_offset(buffer_offset);
298
299 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, src_obj);
300 _buffer_offset_to_source_obj_table->maybe_grow();
301 }
302
303 copy_roots_to_buffer(roots);
304
305 log_info(cds)("Size of heap region = " SIZE_FORMAT " bytes, %d objects, %d roots, %d native ptrs",
306 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
307 }
308
309 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
310 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
311 return byte_size;
312 }
313
314 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
315 assert(is_object_aligned(fill_bytes), "must be");
316 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
317
318 int initial_length = to_array_length(fill_bytes / elemSize);
319 for (int length = initial_length; length >= 0; length --) {
320 size_t array_byte_size = filler_array_byte_size(length);
321 if (array_byte_size == fill_bytes) {
322 return length;
323 }
324 }
325
326 ShouldNotReachHere();
327 return -1;
328 }
329
330 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
331 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
332 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
333 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
334 memset(mem, 0, fill_bytes);
335 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
336 if (UseCompactObjectHeaders) {
337 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk));
338 } else {
339 oopDesc::set_mark(mem, markWord::prototype());
340 cast_to_oop(mem)->set_narrow_klass(nk);
341 }
342 arrayOopDesc::set_length(mem, array_length);
343 return mem;
344 }
345
346 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
347 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
348 // leftover space is smaller than a zero-sized array object). Therefore, we need to
349 // make sure there's enough space of min_filler_byte_size in the current region after
350 // required_byte_size has been allocated. If not, fill the remainder of the current
351 // region.
352 size_t min_filler_byte_size = filler_array_byte_size(0);
353 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
354
355 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
356 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
357
358 if (cur_min_region_bottom != next_min_region_bottom) {
359 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
360 // we can map the region in any region-based collector.
361 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
362 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
363 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
364
365 const size_t filler_end = next_min_region_bottom;
366 const size_t fill_bytes = filler_end - _buffer_used;
367 assert(fill_bytes > 0, "must be");
368 ensure_buffer_space(filler_end);
369
370 int array_length = filler_array_length(fill_bytes);
371 log_info(cds, heap)("Inserting filler obj array of %d elements (" SIZE_FORMAT " bytes total) @ buffer offset " SIZE_FORMAT,
372 array_length, fill_bytes, _buffer_used);
373 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
374 _buffer_used = filler_end;
375 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
376 }
377 }
378
379 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
380 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
381 if (p != nullptr) {
382 assert(*p > 0, "filler must be larger than zero bytes");
383 return *p;
384 } else {
385 return 0; // buffered_addr is not a filler
386 }
387 }
388
389 template <typename T>
390 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
391 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
392 *field_addr = value;
393 }
394
395 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
396 assert(!is_too_large_to_archive(src_obj), "already checked");
397 size_t byte_size = src_obj->size() * HeapWordSize;
398 assert(byte_size > 0, "no zero-size objects");
399
400 // For region-based collectors such as G1, the archive heap may be mapped into
401 // multiple regions. We need to make sure that we don't have an object that can possible
402 // span across two regions.
403 maybe_fill_gc_region_gap(byte_size);
404
405 size_t new_used = _buffer_used + byte_size;
406 assert(new_used > _buffer_used, "no wrap around");
407
408 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
409 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
410 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
411
412 ensure_buffer_space(new_used);
413
414 address from = cast_from_oop<address>(src_obj);
415 address to = offset_to_buffered_address<address>(_buffer_used);
416 assert(is_object_aligned(_buffer_used), "sanity");
417 assert(is_object_aligned(byte_size), "sanity");
418 memcpy(to, from, byte_size);
419
420 // These native pointers will be restored explicitly at run time.
421 if (java_lang_Module::is_instance(src_obj)) {
422 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
423 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
424 #ifdef ASSERT
425 // We only archive these loaders
426 if (src_obj != SystemDictionary::java_platform_loader() &&
427 src_obj != SystemDictionary::java_system_loader()) {
428 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
429 }
430 #endif
431 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
432 }
433
434 size_t buffered_obj_offset = _buffer_used;
435 _buffer_used = new_used;
436
437 return buffered_obj_offset;
438 }
439
440 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
441 assert(!info->is_used(), "only set once");
442 assert(UseG1GC, "must be");
443 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
444 log_info(cds, heap)("Heap end = %p", heap_end);
445
446 size_t heap_region_byte_size = _buffer_used;
447 assert(heap_region_byte_size > 0, "must archived at least one object!");
448
449
450 if (UseCompressedOops) {
451 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
452 } else {
453 // We always write the objects as if the heap started at this address. This
454 // makes the contents of the archive heap deterministic.
455 //
456 // Note that at runtime, the heap address is selected by the OS, so the archive
457 // heap will not be mapped at 0x10000000, and the contents need to be patched.
458 _requested_bottom = (address)NOCOOPS_REQUESTED_BASE;
459 }
460
461 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
462
463 _requested_top = _requested_bottom + _buffer_used;
464
465 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
466 offset_to_buffered_address<HeapWord*>(_buffer_used)));
467 info->set_heap_roots_offset(_heap_roots_offset);
468 }
469
470 // Oop relocation
471
472 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
473 assert(is_in_requested_range(cast_to_oop(p)), "must be");
474
475 address addr = address(p);
476 assert(addr >= _requested_bottom, "must be");
477 size_t offset = addr - _requested_bottom;
478 return offset_to_buffered_address<T*>(offset);
479 }
480
481 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
482 oop o = load_oop_from_buffer(buffered_addr);
483 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
484 return o;
485 }
486
487 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
488 oop request_oop) {
489 assert(is_in_requested_range(request_oop), "must be");
490 store_oop_in_buffer(buffered_addr, request_oop);
491 }
492
493 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
494 *buffered_addr = requested_obj;
495 }
496
497 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
498 narrowOop val = CompressedOops::encode_not_null(requested_obj);
499 *buffered_addr = val;
500 }
501
502 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
503 return *buffered_addr;
504 }
505
506 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
507 return CompressedOops::decode(*buffered_addr);
508 }
509
510 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
511 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
512 if (!CompressedOops::is_null(source_referent)) {
513 oop request_referent = source_obj_to_requested_obj(source_referent);
514 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
515 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
516 }
517 }
518
519 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
520 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
521 address requested_region_bottom;
522
523 assert(request_p >= (T*)_requested_bottom, "sanity");
524 assert(request_p < (T*)_requested_top, "sanity");
525 requested_region_bottom = _requested_bottom;
526
527 // Mark the pointer in the oopmap
528 T* region_bottom = (T*)requested_region_bottom;
529 assert(request_p >= region_bottom, "must be");
530 BitMap::idx_t idx = request_p - region_bottom;
531 assert(idx < oopmap->size(), "overflow");
532 oopmap->set_bit(idx);
533 }
534
535 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
536 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
537 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
538 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
539
540 oop fake_oop = cast_to_oop(buffered_addr);
541 if (UseCompactObjectHeaders) {
542 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk));
543 } else {
544 fake_oop->set_narrow_klass(nk);
545 }
546
547 // We need to retain the identity_hash, because it may have been used by some hashtables
548 // in the shared heap.
549 if (src_obj != nullptr && !src_obj->fast_no_hash_check()) {
550 intptr_t src_hash = src_obj->identity_hash();
551 if (UseCompactObjectHeaders) {
552 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
553 } else {
554 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
555 }
556 assert(fake_oop->mark().is_unlocked(), "sanity");
557
558 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
559 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
560 }
561 }
562
563 // Relocate an element in the buffered copy of HeapShared::roots()
564 template <typename T> void ArchiveHeapWriter::relocate_root_at(oop requested_roots, int index, CHeapBitMap* oopmap) {
565 size_t offset = (size_t)((objArrayOop)requested_roots)->obj_at_offset<T>(index);
566 relocate_field_in_buffer<T>((T*)(buffered_heap_roots_addr() + offset), oopmap);
567 }
568
569 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
570 oop _src_obj;
571 address _buffered_obj;
572 CHeapBitMap* _oopmap;
573
574 public:
575 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
576 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) {}
577
578 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
579 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
580
581 private:
582 template <class T> void do_oop_work(T *p) {
583 size_t field_offset = pointer_delta(p, _src_obj, sizeof(char));
584 ArchiveHeapWriter::relocate_field_in_buffer<T>((T*)(_buffered_obj + field_offset), _oopmap);
585 }
586 };
587
588 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
589 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
590 size_t start = bitmap->find_first_set_bit(0);
591 size_t end = bitmap->size();
592 log_info(cds)("%s = " SIZE_FORMAT_W(7) " ... " SIZE_FORMAT_W(7) " (%3zu%% ... %3zu%% = %3zu%%)", which,
593 start, end,
594 start * 100 / total_bits,
595 end * 100 / total_bits,
596 (end - start) * 100 / total_bits);
597 }
598
599 // Update all oop fields embedded in the buffered objects
600 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
601 ArchiveHeapInfo* heap_info) {
602 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
603 size_t heap_region_byte_size = _buffer_used;
604 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
605
606 for (int i = 0; i < _source_objs_order->length(); i++) {
607 int src_obj_index = _source_objs_order->at(i)._index;
608 oop src_obj = _source_objs->at(src_obj_index);
609 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
610 assert(info != nullptr, "must be");
611 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
612 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
613 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
614 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
615 src_obj->oop_iterate(&relocator);
616 };
617
618 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
619 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
620 oop requested_roots = requested_obj_from_buffer_offset(_heap_roots_offset);
621 update_header_for_requested_obj(requested_roots, nullptr, Universe::objectArrayKlass());
622 int length = roots != nullptr ? roots->length() : 0;
623 for (int i = 0; i < length; i++) {
624 if (UseCompressedOops) {
625 relocate_root_at<narrowOop>(requested_roots, i, heap_info->oopmap());
626 } else {
627 relocate_root_at<oop>(requested_roots, i, heap_info->oopmap());
628 }
629 }
630
631 compute_ptrmap(heap_info);
632
633 size_t total_bytes = (size_t)_buffer->length();
634 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
635 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
636 }
637
638 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
639 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
640 if (ptr != nullptr) {
641 NativePointerInfo info;
642 info._src_obj = src_obj;
643 info._field_offset = field_offset;
644 _native_pointers->append(info);
645 HeapShared::set_has_native_pointers(src_obj);
646 _num_native_ptrs ++;
647 }
648 }
649
650 // Do we have a jlong/jint field that's actually a pointer to a MetaspaceObj?
651 bool ArchiveHeapWriter::is_marked_as_native_pointer(ArchiveHeapInfo* heap_info, oop src_obj, int field_offset) {
652 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
653 assert(p != nullptr, "must be");
654
655 // requested_field_addr = the address of this field in the requested space
656 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
657 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
658 assert((Metadata**)_requested_bottom <= requested_field_addr && requested_field_addr < (Metadata**) _requested_top, "range check");
659
660 BitMap::idx_t idx = requested_field_addr - (Metadata**) _requested_bottom;
661 // Leading zeros have been removed so some addresses may not be in the ptrmap
662 size_t start_pos = FileMapInfo::current_info()->heap_ptrmap_start_pos();
663 if (idx < start_pos) {
664 return false;
665 } else {
666 idx -= start_pos;
667 }
668 return (idx < heap_info->ptrmap()->size()) && (heap_info->ptrmap()->at(idx) == true);
669 }
670
671 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
672 int num_non_null_ptrs = 0;
673 Metadata** bottom = (Metadata**) _requested_bottom;
674 Metadata** top = (Metadata**) _requested_top; // exclusive
675 heap_info->ptrmap()->resize(top - bottom);
676
677 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
678 for (int i = 0; i < _native_pointers->length(); i++) {
679 NativePointerInfo info = _native_pointers->at(i);
680 oop src_obj = info._src_obj;
681 int field_offset = info._field_offset;
682 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
683 // requested_field_addr = the address of this field in the requested space
684 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
685 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
686 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
687
688 // Mark this field in the bitmap
689 BitMap::idx_t idx = requested_field_addr - bottom;
690 heap_info->ptrmap()->set_bit(idx);
691 num_non_null_ptrs ++;
692 max_idx = MAX2(max_idx, idx);
693
694 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
695 // this address if the RO/RW regions are mapped at the default location).
696
697 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
698 Metadata* native_ptr = *buffered_field_addr;
699 assert(native_ptr != nullptr, "sanity");
700
701 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
702 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
703 *buffered_field_addr = (Metadata*)requested_native_ptr;
704 }
705
706 heap_info->ptrmap()->resize(max_idx + 1);
707 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (" SIZE_FORMAT " bits)",
708 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
709 }
710
711 #endif // INCLUDE_CDS_JAVA_HEAP