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 oopDesc::set_mark(mem, markWord::prototype());
209 oopDesc::release_set_klass(mem, k);
210 }
211 {
212 // This is copied from ObjArrayAllocator::initialize
213 arrayOopDesc::set_length(mem, length);
214 }
215
216 objArrayOop arrayOop = objArrayOop(cast_to_oop(mem));
217 for (int i = 0; i < length; i++) {
218 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside of the real heap!
219 oop o = roots->at(i);
220 if (UseCompressedOops) {
221 * arrayOop->obj_at_addr<narrowOop>(i) = CompressedOops::encode(o);
222 } else {
223 * arrayOop->obj_at_addr<oop>(i) = o;
224 }
225 }
226 log_info(cds, heap)("archived obj roots[%d] = " SIZE_FORMAT " bytes, klass = %p, obj = %p", length, byte_size, k, mem);
227
228 _heap_roots_offset = _buffer_used;
229 _buffer_used = new_used;
230 }
231
232 static int oop_sorting_rank(oop o) {
233 bool has_oop_ptr, has_native_ptr;
234 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
235
236 if (!has_oop_ptr) {
237 if (!has_native_ptr) {
238 return 0;
239 } else {
240 return 1;
241 }
242 } else {
243 if (has_native_ptr) {
244 return 2;
245 } else {
246 return 3;
247 }
248 }
249 }
250
251 // The goal is to sort the objects in increasing order of:
252 // - objects that have no pointers
253 // - objects that have only native pointers
254 // - objects that have both native and oop pointers
255 // - objects that have only oop pointers
256 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
257 int rank_a = a->_rank;
258 int rank_b = b->_rank;
259
260 if (rank_a != rank_b) {
261 return rank_a - rank_b;
262 } else {
263 // If they are the same rank, sort them by their position in the _source_objs array
264 return a->_index - b->_index;
265 }
266 }
267
268 void ArchiveHeapWriter::sort_source_objs() {
269 log_info(cds)("sorting heap objects");
270 int len = _source_objs->length();
271 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
272
273 for (int i = 0; i < len; i++) {
274 oop o = _source_objs->at(i);
275 int rank = oop_sorting_rank(o);
276 HeapObjOrder os = {i, rank};
277 _source_objs_order->append(os);
278 }
279 log_info(cds)("computed ranks");
280 _source_objs_order->sort(compare_objs_by_oop_fields);
281 log_info(cds)("sorting heap objects done");
282 }
283
284 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
285 sort_source_objs();
286 for (int i = 0; i < _source_objs_order->length(); i++) {
287 int src_obj_index = _source_objs_order->at(i)._index;
288 oop src_obj = _source_objs->at(src_obj_index);
289 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
290 assert(info != nullptr, "must be");
291 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
292 info->set_buffer_offset(buffer_offset);
293
294 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, src_obj);
295 _buffer_offset_to_source_obj_table->maybe_grow();
296 }
297
298 copy_roots_to_buffer(roots);
299
300 log_info(cds)("Size of heap region = " SIZE_FORMAT " bytes, %d objects, %d roots, %d native ptrs",
301 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
302 }
303
304 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
305 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
306 return byte_size;
307 }
308
309 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
310 assert(is_object_aligned(fill_bytes), "must be");
311 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
312
313 int initial_length = to_array_length(fill_bytes / elemSize);
314 for (int length = initial_length; length >= 0; length --) {
315 size_t array_byte_size = filler_array_byte_size(length);
316 if (array_byte_size == fill_bytes) {
317 return length;
318 }
319 }
320
321 ShouldNotReachHere();
322 return -1;
323 }
324
325 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
326 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
327 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
328 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
329 memset(mem, 0, fill_bytes);
330 oopDesc::set_mark(mem, markWord::prototype());
331 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
332 cast_to_oop(mem)->set_narrow_klass(nk);
333 arrayOopDesc::set_length(mem, array_length);
334 return mem;
335 }
336
337 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
338 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
339 // leftover space is smaller than a zero-sized array object). Therefore, we need to
340 // make sure there's enough space of min_filler_byte_size in the current region after
341 // required_byte_size has been allocated. If not, fill the remainder of the current
342 // region.
343 size_t min_filler_byte_size = filler_array_byte_size(0);
344 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
345
346 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
347 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
348
349 if (cur_min_region_bottom != next_min_region_bottom) {
350 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
351 // we can map the region in any region-based collector.
352 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
353 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
354 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
355
356 const size_t filler_end = next_min_region_bottom;
357 const size_t fill_bytes = filler_end - _buffer_used;
358 assert(fill_bytes > 0, "must be");
359 ensure_buffer_space(filler_end);
360
361 int array_length = filler_array_length(fill_bytes);
362 log_info(cds, heap)("Inserting filler obj array of %d elements (" SIZE_FORMAT " bytes total) @ buffer offset " SIZE_FORMAT,
363 array_length, fill_bytes, _buffer_used);
364 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
365 _buffer_used = filler_end;
366 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
367 }
368 }
369
370 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
371 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
372 if (p != nullptr) {
373 assert(*p > 0, "filler must be larger than zero bytes");
374 return *p;
375 } else {
376 return 0; // buffered_addr is not a filler
377 }
378 }
379
380 template <typename T>
381 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
382 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
383 *field_addr = value;
384 }
385
386 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
387 assert(!is_too_large_to_archive(src_obj), "already checked");
388 size_t byte_size = src_obj->size() * HeapWordSize;
389 assert(byte_size > 0, "no zero-size objects");
390
391 // For region-based collectors such as G1, the archive heap may be mapped into
392 // multiple regions. We need to make sure that we don't have an object that can possible
393 // span across two regions.
394 maybe_fill_gc_region_gap(byte_size);
395
396 size_t new_used = _buffer_used + byte_size;
397 assert(new_used > _buffer_used, "no wrap around");
398
399 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
400 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
401 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
402
403 ensure_buffer_space(new_used);
404
405 address from = cast_from_oop<address>(src_obj);
406 address to = offset_to_buffered_address<address>(_buffer_used);
407 assert(is_object_aligned(_buffer_used), "sanity");
408 assert(is_object_aligned(byte_size), "sanity");
409 memcpy(to, from, byte_size);
410
411 // These native pointers will be restored explicitly at run time.
412 if (java_lang_Module::is_instance(src_obj)) {
413 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
414 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
415 #ifdef ASSERT
416 // We only archive these loaders
417 if (src_obj != SystemDictionary::java_platform_loader() &&
418 src_obj != SystemDictionary::java_system_loader()) {
419 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
420 }
421 #endif
422 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
423 }
424
425 size_t buffered_obj_offset = _buffer_used;
426 _buffer_used = new_used;
427
428 return buffered_obj_offset;
429 }
430
431 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
432 assert(!info->is_used(), "only set once");
433 assert(UseG1GC, "must be");
434 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
435 log_info(cds, heap)("Heap end = %p", heap_end);
436
437 size_t heap_region_byte_size = _buffer_used;
438 assert(heap_region_byte_size > 0, "must archived at least one object!");
439
440
441 if (UseCompressedOops) {
442 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
443 } else {
444 // We always write the objects as if the heap started at this address. This
445 // makes the contents of the archive heap deterministic.
446 //
447 // Note that at runtime, the heap address is selected by the OS, so the archive
448 // heap will not be mapped at 0x10000000, and the contents need to be patched.
449 _requested_bottom = (address)NOCOOPS_REQUESTED_BASE;
450 }
451
452 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
453
454 _requested_top = _requested_bottom + _buffer_used;
455
456 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
457 offset_to_buffered_address<HeapWord*>(_buffer_used)));
458 info->set_heap_roots_offset(_heap_roots_offset);
459 }
460
461 // Oop relocation
462
463 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
464 assert(is_in_requested_range(cast_to_oop(p)), "must be");
465
466 address addr = address(p);
467 assert(addr >= _requested_bottom, "must be");
468 size_t offset = addr - _requested_bottom;
469 return offset_to_buffered_address<T*>(offset);
470 }
471
472 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
473 oop o = load_oop_from_buffer(buffered_addr);
474 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
475 return o;
476 }
477
478 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
479 oop request_oop) {
480 assert(is_in_requested_range(request_oop), "must be");
481 store_oop_in_buffer(buffered_addr, request_oop);
482 }
483
484 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
485 *buffered_addr = requested_obj;
486 }
487
488 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
489 narrowOop val = CompressedOops::encode_not_null(requested_obj);
490 *buffered_addr = val;
491 }
492
493 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
494 return *buffered_addr;
495 }
496
497 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
498 return CompressedOops::decode(*buffered_addr);
499 }
500
501 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
502 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
503 if (!CompressedOops::is_null(source_referent)) {
504 oop request_referent = source_obj_to_requested_obj(source_referent);
505 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
506 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
507 }
508 }
509
510 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
511 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
512 address requested_region_bottom;
513
514 assert(request_p >= (T*)_requested_bottom, "sanity");
515 assert(request_p < (T*)_requested_top, "sanity");
516 requested_region_bottom = _requested_bottom;
517
518 // Mark the pointer in the oopmap
519 T* region_bottom = (T*)requested_region_bottom;
520 assert(request_p >= region_bottom, "must be");
521 BitMap::idx_t idx = request_p - region_bottom;
522 assert(idx < oopmap->size(), "overflow");
523 oopmap->set_bit(idx);
524 }
525
526 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
527 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
528 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
529 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
530
531 oop fake_oop = cast_to_oop(buffered_addr);
532 fake_oop->set_narrow_klass(nk);
533
534 // We need to retain the identity_hash, because it may have been used by some hashtables
535 // in the shared heap.
536 if (src_obj != nullptr && !src_obj->fast_no_hash_check()) {
537 intptr_t src_hash = src_obj->identity_hash();
538 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
539 assert(fake_oop->mark().is_unlocked(), "sanity");
540
541 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
542 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
543 }
544 }
545
546 // Relocate an element in the buffered copy of HeapShared::roots()
547 template <typename T> void ArchiveHeapWriter::relocate_root_at(oop requested_roots, int index, CHeapBitMap* oopmap) {
548 size_t offset = (size_t)((objArrayOop)requested_roots)->obj_at_offset<T>(index);
549 relocate_field_in_buffer<T>((T*)(buffered_heap_roots_addr() + offset), oopmap);
550 }
551
552 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
553 oop _src_obj;
554 address _buffered_obj;
555 CHeapBitMap* _oopmap;
556
557 public:
558 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
559 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) {}
560
561 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
562 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
563
564 private:
565 template <class T> void do_oop_work(T *p) {
566 size_t field_offset = pointer_delta(p, _src_obj, sizeof(char));
567 ArchiveHeapWriter::relocate_field_in_buffer<T>((T*)(_buffered_obj + field_offset), _oopmap);
568 }
569 };
570
571 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
572 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
573 size_t start = bitmap->find_first_set_bit(0);
574 size_t end = bitmap->size();
575 log_info(cds)("%s = " SIZE_FORMAT_W(7) " ... " SIZE_FORMAT_W(7) " (%3zu%% ... %3zu%% = %3zu%%)", which,
576 start, end,
577 start * 100 / total_bits,
578 end * 100 / total_bits,
579 (end - start) * 100 / total_bits);
580 }
581
582 // Update all oop fields embedded in the buffered objects
583 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
584 ArchiveHeapInfo* heap_info) {
585 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
586 size_t heap_region_byte_size = _buffer_used;
587 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
588
589 for (int i = 0; i < _source_objs_order->length(); i++) {
590 int src_obj_index = _source_objs_order->at(i)._index;
591 oop src_obj = _source_objs->at(src_obj_index);
592 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
593 assert(info != nullptr, "must be");
594 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
595 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
596 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
597 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
598 src_obj->oop_iterate(&relocator);
599 };
600
601 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
602 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
603 oop requested_roots = requested_obj_from_buffer_offset(_heap_roots_offset);
604 update_header_for_requested_obj(requested_roots, nullptr, Universe::objectArrayKlass());
605 int length = roots != nullptr ? roots->length() : 0;
606 for (int i = 0; i < length; i++) {
607 if (UseCompressedOops) {
608 relocate_root_at<narrowOop>(requested_roots, i, heap_info->oopmap());
609 } else {
610 relocate_root_at<oop>(requested_roots, i, heap_info->oopmap());
611 }
612 }
613
614 compute_ptrmap(heap_info);
615
616 size_t total_bytes = (size_t)_buffer->length();
617 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
618 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
619 }
620
621 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
622 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
623 if (ptr != nullptr) {
624 NativePointerInfo info;
625 info._src_obj = src_obj;
626 info._field_offset = field_offset;
627 _native_pointers->append(info);
628 HeapShared::set_has_native_pointers(src_obj);
629 _num_native_ptrs ++;
630 }
631 }
632
633 // Do we have a jlong/jint field that's actually a pointer to a MetaspaceObj?
634 bool ArchiveHeapWriter::is_marked_as_native_pointer(ArchiveHeapInfo* heap_info, oop src_obj, int field_offset) {
635 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
636 assert(p != nullptr, "must be");
637
638 // requested_field_addr = the address of this field in the requested space
639 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
640 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
641 assert((Metadata**)_requested_bottom <= requested_field_addr && requested_field_addr < (Metadata**) _requested_top, "range check");
642
643 BitMap::idx_t idx = requested_field_addr - (Metadata**) _requested_bottom;
644 // Leading zeros have been removed so some addresses may not be in the ptrmap
645 size_t start_pos = FileMapInfo::current_info()->heap_ptrmap_start_pos();
646 if (idx < start_pos) {
647 return false;
648 } else {
649 idx -= start_pos;
650 }
651 return (idx < heap_info->ptrmap()->size()) && (heap_info->ptrmap()->at(idx) == true);
652 }
653
654 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
655 int num_non_null_ptrs = 0;
656 Metadata** bottom = (Metadata**) _requested_bottom;
657 Metadata** top = (Metadata**) _requested_top; // exclusive
658 heap_info->ptrmap()->resize(top - bottom);
659
660 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
661 for (int i = 0; i < _native_pointers->length(); i++) {
662 NativePointerInfo info = _native_pointers->at(i);
663 oop src_obj = info._src_obj;
664 int field_offset = info._field_offset;
665 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
666 // requested_field_addr = the address of this field in the requested space
667 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
668 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
669 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
670
671 // Mark this field in the bitmap
672 BitMap::idx_t idx = requested_field_addr - bottom;
673 heap_info->ptrmap()->set_bit(idx);
674 num_non_null_ptrs ++;
675 max_idx = MAX2(max_idx, idx);
676
677 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
678 // this address if the RO/RW regions are mapped at the default location).
679
680 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
681 Metadata* native_ptr = *buffered_field_addr;
682 assert(native_ptr != nullptr, "sanity");
683
684 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
685 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
686 *buffered_field_addr = (Metadata*)requested_native_ptr;
687 }
688
689 heap_info->ptrmap()->resize(max_idx + 1);
690 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (" SIZE_FORMAT " bits)",
691 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
692 }
693
694 #endif // INCLUDE_CDS_JAVA_HEAP