1 /*
2 * Copyright (c) 2023, 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 "cds/regeneratedClasses.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "gc/shared/collectedHeap.hpp"
34 #include "memory/iterator.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/compressedOops.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "oops/objArrayOop.inline.hpp"
40 #include "oops/oopHandle.inline.hpp"
41 #include "oops/typeArrayKlass.hpp"
42 #include "oops/typeArrayOop.hpp"
43 #include "runtime/java.hpp"
44 #include "runtime/mutexLocker.hpp"
45 #include "utilities/bitMap.inline.hpp"
46 #if INCLUDE_G1GC
47 #include "gc/g1/g1CollectedHeap.hpp"
48 #include "gc/g1/g1HeapRegion.hpp"
49 #endif
50
51 #if INCLUDE_CDS_JAVA_HEAP
52
53 GrowableArrayCHeap<u1, mtClassShared>* ArchiveHeapWriter::_buffer = nullptr;
54
55 // The following are offsets from buffer_bottom()
56 size_t ArchiveHeapWriter::_buffer_used;
57
58 // Heap root segments
59 HeapRootSegments ArchiveHeapWriter::_heap_root_segments;
60
61 address ArchiveHeapWriter::_requested_bottom;
62 address ArchiveHeapWriter::_requested_top;
63
64 static size_t _num_strings = 0;
65 static size_t _string_bytes = 0;
66 static size_t _num_packages = 0;
67 static size_t _num_protection_domains = 0;
68
69 GrowableArrayCHeap<ArchiveHeapWriter::NativePointerInfo, mtClassShared>* ArchiveHeapWriter::_native_pointers;
70 GrowableArrayCHeap<oop, mtClassShared>* ArchiveHeapWriter::_source_objs;
71 GrowableArrayCHeap<ArchiveHeapWriter::HeapObjOrder, mtClassShared>* ArchiveHeapWriter::_source_objs_order;
72
73 ArchiveHeapWriter::BufferOffsetToSourceObjectTable*
74 ArchiveHeapWriter::_buffer_offset_to_source_obj_table = nullptr;
75
76
77 typedef ResourceHashtable<
78 size_t, // offset of a filler from ArchiveHeapWriter::buffer_bottom()
79 size_t, // size of this filler (in bytes)
80 127, // prime number
81 AnyObj::C_HEAP,
82 mtClassShared> FillersTable;
83 static FillersTable* _fillers;
84 static int _num_native_ptrs = 0;
85
86 void ArchiveHeapWriter::init() {
87 if (HeapShared::can_write()) {
88 Universe::heap()->collect(GCCause::_java_lang_system_gc);
89
90 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M);
91 _fillers = new FillersTable();
92 _requested_bottom = nullptr;
93 _requested_top = nullptr;
94
95 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048);
96 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
97
98 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
99 }
100 }
101
102 void ArchiveHeapWriter::add_source_obj(oop src_obj) {
103 _source_objs->append(src_obj);
104 }
105
106 void ArchiveHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots,
107 ArchiveHeapInfo* heap_info) {
108 assert(HeapShared::can_write(), "sanity");
109 allocate_buffer();
110 copy_source_objs_to_buffer(roots);
111 set_requested_address(heap_info);
112 relocate_embedded_oops(roots, heap_info);
113 }
114
115 bool ArchiveHeapWriter::is_too_large_to_archive(oop o) {
116 return is_too_large_to_archive(o->size());
117 }
118
119 bool ArchiveHeapWriter::is_string_too_large_to_archive(oop string) {
120 typeArrayOop value = java_lang_String::value_no_keepalive(string);
121 return is_too_large_to_archive(value);
122 }
123
124 bool ArchiveHeapWriter::is_too_large_to_archive(size_t size) {
125 assert(size > 0, "no zero-size object");
126 assert(size * HeapWordSize > size, "no overflow");
127 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive");
128
129 size_t byte_size = size * HeapWordSize;
130 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) {
131 return true;
132 } else {
133 return false;
134 }
135 }
136
137 // Various lookup functions between source_obj, buffered_obj and requested_obj
138 bool ArchiveHeapWriter::is_in_requested_range(oop o) {
139 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized");
140 address a = cast_from_oop<address>(o);
141 return (_requested_bottom <= a && a < _requested_top);
142 }
143
144 oop ArchiveHeapWriter::requested_obj_from_buffer_offset(size_t offset) {
145 oop req_obj = cast_to_oop(_requested_bottom + offset);
146 assert(is_in_requested_range(req_obj), "must be");
147 return req_obj;
148 }
149
150 oop ArchiveHeapWriter::source_obj_to_requested_obj(oop src_obj) {
151 assert(CDSConfig::is_dumping_heap(), "dump-time only");
152 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
153 if (p != nullptr) {
154 return requested_obj_from_buffer_offset(p->buffer_offset());
155 } else {
156 return nullptr;
157 }
158 }
159
160 oop ArchiveHeapWriter::buffered_addr_to_source_obj(address buffered_addr) {
161 oop* p = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr));
162 if (p != nullptr) {
163 return *p;
164 } else {
165 return nullptr;
166 }
167 }
168
169 address ArchiveHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) {
170 return _requested_bottom + buffered_address_to_offset(buffered_addr);
171 }
172
173 address ArchiveHeapWriter::requested_address() {
174 assert(_buffer != nullptr, "must be initialized");
175 return _requested_bottom;
176 }
177
178 void ArchiveHeapWriter::allocate_buffer() {
179 int initial_buffer_size = 100000;
180 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size);
181 _buffer_used = 0;
182 ensure_buffer_space(1); // so that buffer_bottom() works
183 }
184
185 void ArchiveHeapWriter::ensure_buffer_space(size_t min_bytes) {
186 // We usually have very small heaps. If we get a huge one it's probably caused by a bug.
187 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects");
188 _buffer->at_grow(to_array_index(min_bytes));
189 }
190
191 objArrayOop ArchiveHeapWriter::allocate_root_segment(size_t offset, int element_count) {
192 HeapWord* mem = offset_to_buffered_address<HeapWord *>(offset);
193 memset(mem, 0, objArrayOopDesc::object_size(element_count));
194
195 // The initialization code is copied from MemAllocator::finish and ObjArrayAllocator::initialize.
196 oopDesc::set_mark(mem, markWord::prototype());
197 oopDesc::release_set_klass(mem, Universe::objectArrayKlass());
198 arrayOopDesc::set_length(mem, element_count);
199 return objArrayOop(cast_to_oop(mem));
200 }
201
202 void ArchiveHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) {
203 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap!
204 if (UseCompressedOops) {
205 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root);
206 } else {
207 *segment->obj_at_addr<oop>(index) = root;
208 }
209 }
210
211 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
212 // Depending on the number of classes we are archiving, a single roots array may be
213 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which
214 // allows us to chop the large array into a series of "segments". Current layout
215 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end
216 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT.
217 // This is simple and efficient. We do not need filler objects anywhere between the segments,
218 // or immediately after the last segment. This allows starting the object dump immediately
219 // after the roots.
220
221 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0,
222 "Pre-condition: Roots start at aligned boundary: " SIZE_FORMAT, _buffer_used);
223
224 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize);
225 assert(objArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT,
226 "Should match exactly");
227
228 HeapRootSegments segments(_buffer_used,
229 roots->length(),
230 MIN_GC_REGION_ALIGNMENT,
231 max_elem_count);
232
233 int root_index = 0;
234 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) {
235 int size_elems = segments.size_in_elems(seg_idx);
236 size_t size_bytes = segments.size_in_bytes(seg_idx);
237
238 size_t oop_offset = _buffer_used;
239 _buffer_used = oop_offset + size_bytes;
240 ensure_buffer_space(_buffer_used);
241
242 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0,
243 "Roots segment " SIZE_FORMAT " start is not aligned: " SIZE_FORMAT,
244 segments.count(), oop_offset);
245
246 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems);
247 for (int i = 0; i < size_elems; i++) {
248 root_segment_at_put(seg_oop, i, roots->at(root_index++));
249 }
250
251 log_info(cds, heap)("archived obj root segment [%d] = " SIZE_FORMAT " bytes, obj = " PTR_FORMAT,
252 size_elems, size_bytes, p2i(seg_oop));
253 }
254
255 _heap_root_segments = segments;
256 }
257
258 // The goal is to sort the objects in increasing order of:
259 // - objects that have only oop pointers
260 // - objects that have both native and oop pointers
261 // - objects that have only native pointers
262 // - objects that have no pointers
263 static int oop_sorting_rank(oop o) {
264 bool has_oop_ptr, has_native_ptr;
265 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
266
267 if (has_oop_ptr) {
268 if (!has_native_ptr) {
269 return 0;
270 } else {
271 return 1;
272 }
273 } else {
274 if (has_native_ptr) {
275 return 2;
276 } else {
277 return 3;
278 }
279 }
280 }
281
282 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
283 int rank_a = a->_rank;
284 int rank_b = b->_rank;
285
286 if (rank_a != rank_b) {
287 return rank_a - rank_b;
288 } else {
289 // If they are the same rank, sort them by their position in the _source_objs array
290 return a->_index - b->_index;
291 }
292 }
293
294 void ArchiveHeapWriter::sort_source_objs() {
295 log_info(cds)("sorting heap objects");
296 int len = _source_objs->length();
297 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
298
299 for (int i = 0; i < len; i++) {
300 oop o = _source_objs->at(i);
301 int rank = oop_sorting_rank(o);
302 HeapObjOrder os = {i, rank};
303 _source_objs_order->append(os);
304 }
305 log_info(cds)("computed ranks");
306 _source_objs_order->sort(compare_objs_by_oop_fields);
307 log_info(cds)("sorting heap objects done");
308 }
309
310 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
311 // There could be multiple root segments, which we want to be aligned by region.
312 // Putting them ahead of objects makes sure we waste no space.
313 copy_roots_to_buffer(roots);
314
315 sort_source_objs();
316 for (int i = 0; i < _source_objs_order->length(); i++) {
317 int src_obj_index = _source_objs_order->at(i)._index;
318 oop src_obj = _source_objs->at(src_obj_index);
319 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
320 assert(info != nullptr, "must be");
321 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
322 info->set_buffer_offset(buffer_offset);
323
324 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, src_obj);
325 _buffer_offset_to_source_obj_table->maybe_grow();
326 }
327
328 log_info(cds)("Size of heap region = " SIZE_FORMAT " bytes, %d objects, %d roots, %d native ptrs",
329 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
330 log_info(cds)(" strings = " SIZE_FORMAT_W(8) " (" SIZE_FORMAT " bytes)", _num_strings, _string_bytes);
331 log_info(cds)(" packages = " SIZE_FORMAT_W(8), _num_packages);
332 log_info(cds)(" protection domains = " SIZE_FORMAT_W(8),_num_protection_domains);
333 }
334
335 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
336 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
337 return byte_size;
338 }
339
340 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
341 assert(is_object_aligned(fill_bytes), "must be");
342 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
343
344 int initial_length = to_array_length(fill_bytes / elemSize);
345 for (int length = initial_length; length >= 0; length --) {
346 size_t array_byte_size = filler_array_byte_size(length);
347 if (array_byte_size == fill_bytes) {
348 return length;
349 }
350 }
351
352 ShouldNotReachHere();
353 return -1;
354 }
355
356 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
357 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
358 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
359 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
360 memset(mem, 0, fill_bytes);
361 oopDesc::set_mark(mem, markWord::prototype());
362 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
363 cast_to_oop(mem)->set_narrow_klass(nk);
364 arrayOopDesc::set_length(mem, array_length);
365 return mem;
366 }
367
368 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
369 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
370 // leftover space is smaller than a zero-sized array object). Therefore, we need to
371 // make sure there's enough space of min_filler_byte_size in the current region after
372 // required_byte_size has been allocated. If not, fill the remainder of the current
373 // region.
374 size_t min_filler_byte_size = filler_array_byte_size(0);
375 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
376
377 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
378 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
379
380 if (cur_min_region_bottom != next_min_region_bottom) {
381 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
382 // we can map the region in any region-based collector.
383 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
384 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
385 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
386
387 const size_t filler_end = next_min_region_bottom;
388 const size_t fill_bytes = filler_end - _buffer_used;
389 assert(fill_bytes > 0, "must be");
390 ensure_buffer_space(filler_end);
391
392 int array_length = filler_array_length(fill_bytes);
393 log_info(cds, heap)("Inserting filler obj array of %d elements (" SIZE_FORMAT " bytes total) @ buffer offset " SIZE_FORMAT,
394 array_length, fill_bytes, _buffer_used);
395 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
396 _buffer_used = filler_end;
397 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
398 }
399 }
400
401 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
402 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
403 if (p != nullptr) {
404 assert(*p > 0, "filler must be larger than zero bytes");
405 return *p;
406 } else {
407 return 0; // buffered_addr is not a filler
408 }
409 }
410
411 template <typename T>
412 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
413 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
414 *field_addr = value;
415 }
416
417 void ArchiveHeapWriter::update_stats(oop src_obj) {
418 if (java_lang_String::is_instance(src_obj)) {
419 _num_strings ++;
420 _string_bytes += src_obj->size() * HeapWordSize;
421 _string_bytes += java_lang_String::value(src_obj)->size() * HeapWordSize;
422 } else {
423 Klass* k = src_obj->klass();
424 Symbol* name = k->name();
425 if (name->equals("java/lang/NamedPackage") || name->equals("java/lang/Package")) {
426 _num_packages ++;
427 } else if (name->equals("java/security/ProtectionDomain")) {
428 _num_protection_domains ++;
429 }
430 }
431 }
432
433 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
434 update_stats(src_obj);
435
436 assert(!is_too_large_to_archive(src_obj), "already checked");
437 size_t byte_size = src_obj->size() * HeapWordSize;
438 assert(byte_size > 0, "no zero-size objects");
439
440 // For region-based collectors such as G1, the archive heap may be mapped into
441 // multiple regions. We need to make sure that we don't have an object that can possible
442 // span across two regions.
443 maybe_fill_gc_region_gap(byte_size);
444
445 size_t new_used = _buffer_used + byte_size;
446 assert(new_used > _buffer_used, "no wrap around");
447
448 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
449 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
450 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
451
452 ensure_buffer_space(new_used);
453
454 address from = cast_from_oop<address>(src_obj);
455 address to = offset_to_buffered_address<address>(_buffer_used);
456 assert(is_object_aligned(_buffer_used), "sanity");
457 assert(is_object_aligned(byte_size), "sanity");
458 memcpy(to, from, byte_size);
459
460 // These native pointers will be restored explicitly at run time.
461 if (java_lang_Module::is_instance(src_obj)) {
462 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
463 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
464 #ifdef ASSERT
465 // We only archive these loaders
466 if (src_obj != SystemDictionary::java_platform_loader() &&
467 src_obj != SystemDictionary::java_system_loader()) {
468 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
469 }
470 #endif
471 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
472 }
473
474 size_t buffered_obj_offset = _buffer_used;
475 _buffer_used = new_used;
476
477 return buffered_obj_offset;
478 }
479
480 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
481 assert(!info->is_used(), "only set once");
482
483 size_t heap_region_byte_size = _buffer_used;
484 assert(heap_region_byte_size > 0, "must archived at least one object!");
485
486 if (UseCompressedOops) {
487 if (UseG1GC) {
488 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
489 log_info(cds, heap)("Heap end = %p", heap_end);
490 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
491 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT);
492 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
493 } else {
494 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT);
495 }
496 } else {
497 // We always write the objects as if the heap started at this address. This
498 // makes the contents of the archive heap deterministic.
499 //
500 // Note that at runtime, the heap address is selected by the OS, so the archive
501 // heap will not be mapped at 0x10000000, and the contents need to be patched.
502 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT);
503 }
504
505 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity");
506
507 _requested_top = _requested_bottom + _buffer_used;
508
509 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
510 offset_to_buffered_address<HeapWord*>(_buffer_used)));
511 info->set_heap_root_segments(_heap_root_segments);
512 }
513
514 // Oop relocation
515
516 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
517 assert(is_in_requested_range(cast_to_oop(p)), "must be");
518
519 address addr = address(p);
520 assert(addr >= _requested_bottom, "must be");
521 size_t offset = addr - _requested_bottom;
522 return offset_to_buffered_address<T*>(offset);
523 }
524
525 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
526 oop o = load_oop_from_buffer(buffered_addr);
527 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
528 return o;
529 }
530
531 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
532 oop request_oop) {
533 assert(is_in_requested_range(request_oop), "must be");
534 store_oop_in_buffer(buffered_addr, request_oop);
535 }
536
537 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
538 *buffered_addr = requested_obj;
539 }
540
541 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
542 narrowOop val = CompressedOops::encode_not_null(requested_obj);
543 *buffered_addr = val;
544 }
545
546 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
547 return *buffered_addr;
548 }
549
550 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
551 return CompressedOops::decode(*buffered_addr);
552 }
553
554 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
555 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
556 if (source_referent != nullptr) {
557 if (java_lang_Class::is_instance(source_referent)) {
558 source_referent = HeapShared::scratch_java_mirror(source_referent);
559 assert(source_referent != nullptr, "must be");
560 }
561 oop request_referent = source_obj_to_requested_obj(source_referent);
562 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
563 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
564 }
565 }
566
567 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
568 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
569 address requested_region_bottom;
570
571 assert(request_p >= (T*)_requested_bottom, "sanity");
572 assert(request_p < (T*)_requested_top, "sanity");
573 requested_region_bottom = _requested_bottom;
574
575 // Mark the pointer in the oopmap
576 T* region_bottom = (T*)requested_region_bottom;
577 assert(request_p >= region_bottom, "must be");
578 BitMap::idx_t idx = request_p - region_bottom;
579 assert(idx < oopmap->size(), "overflow");
580 oopmap->set_bit(idx);
581 }
582
583 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
584 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
585 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
586 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
587
588 oop fake_oop = cast_to_oop(buffered_addr);
589 fake_oop->set_narrow_klass(nk);
590
591 // We need to retain the identity_hash, because it may have been used by some hashtables
592 // in the shared heap.
593 if (src_obj != nullptr && !src_obj->fast_no_hash_check()) {
594 intptr_t src_hash = src_obj->identity_hash();
595 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
596 assert(fake_oop->mark().is_unlocked(), "sanity");
597
598 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
599 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
600 }
601 }
602
603 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
604 oop _src_obj;
605 address _buffered_obj;
606 CHeapBitMap* _oopmap;
607
608 public:
609 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
610 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) {}
611
612 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
613 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
614
615 private:
616 template <class T> void do_oop_work(T *p) {
617 size_t field_offset = pointer_delta(p, _src_obj, sizeof(char));
618 ArchiveHeapWriter::relocate_field_in_buffer<T>((T*)(_buffered_obj + field_offset), _oopmap);
619 }
620 };
621
622 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
623 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
624 size_t start = bitmap->find_first_set_bit(0);
625 size_t end = bitmap->size();
626 log_info(cds)("%s = " SIZE_FORMAT_W(7) " ... " SIZE_FORMAT_W(7) " (%3zu%% ... %3zu%% = %3zu%%)", which,
627 start, end,
628 start * 100 / total_bits,
629 end * 100 / total_bits,
630 (end - start) * 100 / total_bits);
631 }
632
633 // Update all oop fields embedded in the buffered objects
634 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
635 ArchiveHeapInfo* heap_info) {
636 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
637 size_t heap_region_byte_size = _buffer_used;
638 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
639
640 for (int i = 0; i < _source_objs_order->length(); i++) {
641 int src_obj_index = _source_objs_order->at(i)._index;
642 oop src_obj = _source_objs->at(src_obj_index);
643 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
644 assert(info != nullptr, "must be");
645 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
646 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
647 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
648 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
649 src_obj->oop_iterate(&relocator);
650 };
651
652 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
653 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
654 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
655 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx);
656
657 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset);
658 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass());
659 address buffered_obj = offset_to_buffered_address<address>(seg_offset);
660 int length = _heap_root_segments.size_in_elems(seg_idx);
661
662 if (UseCompressedOops) {
663 for (int i = 0; i < length; i++) {
664 narrowOop* addr = (narrowOop*)(buffered_obj + objArrayOopDesc::obj_at_offset<narrowOop>(i));
665 relocate_field_in_buffer<narrowOop>(addr, heap_info->oopmap());
666 }
667 } else {
668 for (int i = 0; i < length; i++) {
669 oop* addr = (oop*)(buffered_obj + objArrayOopDesc::obj_at_offset<oop>(i));
670 relocate_field_in_buffer<oop>(addr, heap_info->oopmap());
671 }
672 }
673 }
674
675 compute_ptrmap(heap_info);
676
677 size_t total_bytes = (size_t)_buffer->length();
678 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
679 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
680 }
681
682 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
683 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
684 if (ptr != nullptr) {
685 NativePointerInfo info;
686 info._src_obj = src_obj;
687 info._field_offset = field_offset;
688 _native_pointers->append(info);
689 if (!ArchiveBuilder::current()->has_been_archived((address)ptr)) {
690 // Currently we supporting marking of only Method and Klass, both of which are
691 // subtypes of MetaData.
692 ResourceMark rm;
693 log_error(cds, heap)("Native pointer %p is not archived", ptr);
694 if (((Metadata*)ptr)->is_method()) {
695 log_error(cds, heap)("Method: %s", ((Method*)ptr)->external_name());
696 } else {
697 assert(((Metadata*)ptr)->is_klass(), "must be");
698 log_error(cds, heap)("Klass: %s", ((Klass*)ptr)->external_name());
699 }
700 HeapShared::exit_on_error();
701 }
702 HeapShared::set_has_native_pointers(src_obj);
703 _num_native_ptrs ++;
704 }
705 }
706
707 // Do we have a jlong/jint field that's actually a pointer to a MetaspaceObj?
708 bool ArchiveHeapWriter::is_marked_as_native_pointer(ArchiveHeapInfo* heap_info, oop src_obj, int field_offset) {
709 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
710 assert(p != nullptr, "must be");
711
712 // requested_field_addr = the address of this field in the requested space
713 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
714 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
715 assert((Metadata**)_requested_bottom <= requested_field_addr && requested_field_addr < (Metadata**) _requested_top, "range check");
716
717 BitMap::idx_t idx = requested_field_addr - (Metadata**) _requested_bottom;
718 // Leading zeros have been removed so some addresses may not be in the ptrmap
719 size_t start_pos = FileMapInfo::current_info()->heap_ptrmap_start_pos();
720 if (idx < start_pos) {
721 return false;
722 } else {
723 idx -= start_pos;
724 }
725 return (idx < heap_info->ptrmap()->size()) && (heap_info->ptrmap()->at(idx) == true);
726 }
727
728 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
729 int num_non_null_ptrs = 0;
730 Metadata** bottom = (Metadata**) _requested_bottom;
731 Metadata** top = (Metadata**) _requested_top; // exclusive
732 heap_info->ptrmap()->resize(top - bottom);
733
734 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
735 for (int i = 0; i < _native_pointers->length(); i++) {
736 NativePointerInfo info = _native_pointers->at(i);
737 oop src_obj = info._src_obj;
738 int field_offset = info._field_offset;
739 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
740 // requested_field_addr = the address of this field in the requested space
741 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
742 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
743 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
744
745 // Mark this field in the bitmap
746 BitMap::idx_t idx = requested_field_addr - bottom;
747 heap_info->ptrmap()->set_bit(idx);
748 num_non_null_ptrs ++;
749 max_idx = MAX2(max_idx, idx);
750
751 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
752 // this address if the RO/RW regions are mapped at the default location).
753
754 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
755 Metadata* native_ptr = *buffered_field_addr;
756 assert(native_ptr != nullptr, "sanity");
757
758 if (RegeneratedClasses::has_been_regenerated((address)native_ptr)) {
759 native_ptr = (Metadata*)RegeneratedClasses::get_regenerated_object((address)native_ptr);
760 }
761
762 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
763 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
764 *buffered_field_addr = (Metadata*)requested_native_ptr;
765 }
766
767 heap_info->ptrmap()->resize(max_idx + 1);
768 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (" SIZE_FORMAT " bits)",
769 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
770 }
771
772 #endif // INCLUDE_CDS_JAVA_HEAP