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/objArrayOop.inline.hpp"
39 #include "oops/oop.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 if (UseCompactObjectHeaders) {
197 oopDesc::release_set_mark(mem, Universe::objectArrayKlass()->prototype_header());
198 } else {
199 oopDesc::set_mark(mem, markWord::prototype());
200 oopDesc::release_set_klass(mem, Universe::objectArrayKlass());
201 }
202 arrayOopDesc::set_length(mem, element_count);
203 return objArrayOop(cast_to_oop(mem));
204 }
205
206 void ArchiveHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) {
207 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap!
208 if (UseCompressedOops) {
209 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root);
210 } else {
211 *segment->obj_at_addr<oop>(index) = root;
212 }
213 }
214
215 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
216 // Depending on the number of classes we are archiving, a single roots array may be
217 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which
218 // allows us to chop the large array into a series of "segments". Current layout
219 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end
220 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT.
221 // This is simple and efficient. We do not need filler objects anywhere between the segments,
222 // or immediately after the last segment. This allows starting the object dump immediately
223 // after the roots.
224
225 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0,
226 "Pre-condition: Roots start at aligned boundary: " SIZE_FORMAT, _buffer_used);
227
228 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize);
229 assert(objArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT,
230 "Should match exactly");
231
232 HeapRootSegments segments(_buffer_used,
233 roots->length(),
234 MIN_GC_REGION_ALIGNMENT,
235 max_elem_count);
236
237 int root_index = 0;
238 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) {
239 int size_elems = segments.size_in_elems(seg_idx);
240 size_t size_bytes = segments.size_in_bytes(seg_idx);
241
242 size_t oop_offset = _buffer_used;
243 _buffer_used = oop_offset + size_bytes;
244 ensure_buffer_space(_buffer_used);
245
246 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0,
247 "Roots segment " SIZE_FORMAT " start is not aligned: " SIZE_FORMAT,
248 segments.count(), oop_offset);
249
250 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems);
251 for (int i = 0; i < size_elems; i++) {
252 root_segment_at_put(seg_oop, i, roots->at(root_index++));
253 }
254
255 log_info(cds, heap)("archived obj root segment [%d] = " SIZE_FORMAT " bytes, obj = " PTR_FORMAT,
256 size_elems, size_bytes, p2i(seg_oop));
257 }
258
259 assert(root_index == roots->length(), "Post-condition: All roots are handled");
260
261 _heap_root_segments = segments;
262 }
263
264 // The goal is to sort the objects in increasing order of:
265 // - objects that have only oop pointers
266 // - objects that have both native and oop pointers
267 // - objects that have only native pointers
268 // - objects that have no pointers
269 static int oop_sorting_rank(oop o) {
270 bool has_oop_ptr, has_native_ptr;
271 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
272
273 if (has_oop_ptr) {
274 if (!has_native_ptr) {
275 return 0;
276 } else {
277 return 1;
278 }
279 } else {
280 if (has_native_ptr) {
281 return 2;
282 } else {
283 return 3;
284 }
285 }
286 }
287
288 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
289 int rank_a = a->_rank;
290 int rank_b = b->_rank;
291
292 if (rank_a != rank_b) {
293 return rank_a - rank_b;
294 } else {
295 // If they are the same rank, sort them by their position in the _source_objs array
296 return a->_index - b->_index;
297 }
298 }
299
300 void ArchiveHeapWriter::sort_source_objs() {
301 log_info(cds)("sorting heap objects");
302 int len = _source_objs->length();
303 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
304
305 for (int i = 0; i < len; i++) {
306 oop o = _source_objs->at(i);
307 int rank = oop_sorting_rank(o);
308 HeapObjOrder os = {i, rank};
309 _source_objs_order->append(os);
310 }
311 log_info(cds)("computed ranks");
312 _source_objs_order->sort(compare_objs_by_oop_fields);
313 log_info(cds)("sorting heap objects done");
314 }
315
316 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
317 // There could be multiple root segments, which we want to be aligned by region.
318 // Putting them ahead of objects makes sure we waste no space.
319 copy_roots_to_buffer(roots);
320
321 sort_source_objs();
322 for (int i = 0; i < _source_objs_order->length(); i++) {
323 int src_obj_index = _source_objs_order->at(i)._index;
324 oop src_obj = _source_objs->at(src_obj_index);
325 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
326 assert(info != nullptr, "must be");
327 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
328 info->set_buffer_offset(buffer_offset);
329 assert(buffer_offset <= 0x7fffffff, "sanity");
330 HeapShared::add_to_permanent_oop_table(src_obj, (int)buffer_offset);
331
332 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, src_obj);
333 _buffer_offset_to_source_obj_table->maybe_grow();
334 }
335
336 log_info(cds)("Size of heap region = " SIZE_FORMAT " bytes, %d objects, %d roots, %d native ptrs",
337 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
338 log_info(cds)(" strings = " SIZE_FORMAT_W(8) " (" SIZE_FORMAT " bytes)", _num_strings, _string_bytes);
339 log_info(cds)(" packages = " SIZE_FORMAT_W(8), _num_packages);
340 log_info(cds)(" protection domains = " SIZE_FORMAT_W(8),_num_protection_domains);
341 }
342
343 size_t ArchiveHeapWriter::filler_array_byte_size(int length) {
344 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
345 return byte_size;
346 }
347
348 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) {
349 assert(is_object_aligned(fill_bytes), "must be");
350 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
351
352 int initial_length = to_array_length(fill_bytes / elemSize);
353 for (int length = initial_length; length >= 0; length --) {
354 size_t array_byte_size = filler_array_byte_size(length);
355 if (array_byte_size == fill_bytes) {
356 return length;
357 }
358 }
359
360 ShouldNotReachHere();
361 return -1;
362 }
363
364 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
365 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
366 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
367 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
368 memset(mem, 0, fill_bytes);
369 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
370 if (UseCompactObjectHeaders) {
371 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk));
372 } else {
373 oopDesc::set_mark(mem, markWord::prototype());
374 cast_to_oop(mem)->set_narrow_klass(nk);
375 }
376 arrayOopDesc::set_length(mem, array_length);
377 return mem;
378 }
379
380 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
381 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
382 // leftover space is smaller than a zero-sized array object). Therefore, we need to
383 // make sure there's enough space of min_filler_byte_size in the current region after
384 // required_byte_size has been allocated. If not, fill the remainder of the current
385 // region.
386 size_t min_filler_byte_size = filler_array_byte_size(0);
387 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
388
389 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
390 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
391
392 if (cur_min_region_bottom != next_min_region_bottom) {
393 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
394 // we can map the region in any region-based collector.
395 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
396 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
397 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
398
399 const size_t filler_end = next_min_region_bottom;
400 const size_t fill_bytes = filler_end - _buffer_used;
401 assert(fill_bytes > 0, "must be");
402 ensure_buffer_space(filler_end);
403
404 int array_length = filler_array_length(fill_bytes);
405 log_info(cds, heap)("Inserting filler obj array of %d elements (" SIZE_FORMAT " bytes total) @ buffer offset " SIZE_FORMAT,
406 array_length, fill_bytes, _buffer_used);
407 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
408 _buffer_used = filler_end;
409 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
410 }
411 }
412
413 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) {
414 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
415 if (p != nullptr) {
416 assert(*p > 0, "filler must be larger than zero bytes");
417 return *p;
418 } else {
419 return 0; // buffered_addr is not a filler
420 }
421 }
422
423 template <typename T>
424 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
425 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
426 *field_addr = value;
427 }
428
429 void ArchiveHeapWriter::update_stats(oop src_obj) {
430 if (java_lang_String::is_instance(src_obj)) {
431 _num_strings ++;
432 _string_bytes += src_obj->size() * HeapWordSize;
433 _string_bytes += java_lang_String::value(src_obj)->size() * HeapWordSize;
434 } else {
435 Klass* k = src_obj->klass();
436 Symbol* name = k->name();
437 if (name->equals("java/lang/NamedPackage") || name->equals("java/lang/Package")) {
438 _num_packages ++;
439 } else if (name->equals("java/security/ProtectionDomain")) {
440 _num_protection_domains ++;
441 }
442 }
443 }
444
445 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
446 update_stats(src_obj);
447
448 assert(!is_too_large_to_archive(src_obj), "already checked");
449 size_t byte_size = src_obj->size() * HeapWordSize;
450 assert(byte_size > 0, "no zero-size objects");
451
452 // For region-based collectors such as G1, the archive heap may be mapped into
453 // multiple regions. We need to make sure that we don't have an object that can possible
454 // span across two regions.
455 maybe_fill_gc_region_gap(byte_size);
456
457 size_t new_used = _buffer_used + byte_size;
458 assert(new_used > _buffer_used, "no wrap around");
459
460 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
461 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
462 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
463
464 ensure_buffer_space(new_used);
465
466 address from = cast_from_oop<address>(src_obj);
467 address to = offset_to_buffered_address<address>(_buffer_used);
468 assert(is_object_aligned(_buffer_used), "sanity");
469 assert(is_object_aligned(byte_size), "sanity");
470 memcpy(to, from, byte_size);
471
472 // These native pointers will be restored explicitly at run time.
473 if (java_lang_Module::is_instance(src_obj)) {
474 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
475 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
476 #ifdef ASSERT
477 // We only archive these loaders
478 if (src_obj != SystemDictionary::java_platform_loader() &&
479 src_obj != SystemDictionary::java_system_loader()) {
480 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
481 }
482 #endif
483 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
484 }
485
486 size_t buffered_obj_offset = _buffer_used;
487 _buffer_used = new_used;
488
489 return buffered_obj_offset;
490 }
491
492 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) {
493 assert(!info->is_used(), "only set once");
494
495 size_t heap_region_byte_size = _buffer_used;
496 assert(heap_region_byte_size > 0, "must archived at least one object!");
497
498 if (UseCompressedOops) {
499 if (UseG1GC) {
500 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
501 log_info(cds, heap)("Heap end = %p", heap_end);
502 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
503 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT);
504 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
505 } else {
506 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT);
507 }
508 } else {
509 // We always write the objects as if the heap started at this address. This
510 // makes the contents of the archive heap deterministic.
511 //
512 // Note that at runtime, the heap address is selected by the OS, so the archive
513 // heap will not be mapped at 0x10000000, and the contents need to be patched.
514 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT);
515 }
516
517 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity");
518
519 _requested_top = _requested_bottom + _buffer_used;
520
521 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
522 offset_to_buffered_address<HeapWord*>(_buffer_used)));
523 info->set_heap_root_segments(_heap_root_segments);
524 }
525
526 // Oop relocation
527
528 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) {
529 assert(is_in_requested_range(cast_to_oop(p)), "must be");
530
531 address addr = address(p);
532 assert(addr >= _requested_bottom, "must be");
533 size_t offset = addr - _requested_bottom;
534 return offset_to_buffered_address<T*>(offset);
535 }
536
537 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
538 oop o = load_oop_from_buffer(buffered_addr);
539 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
540 return o;
541 }
542
543 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
544 oop request_oop) {
545 assert(is_in_requested_range(request_oop), "must be");
546 store_oop_in_buffer(buffered_addr, request_oop);
547 }
548
549 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
550 *buffered_addr = requested_obj;
551 }
552
553 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
554 narrowOop val = CompressedOops::encode_not_null(requested_obj);
555 *buffered_addr = val;
556 }
557
558 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
559 return *buffered_addr;
560 }
561
562 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
563 return CompressedOops::decode(*buffered_addr);
564 }
565
566 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) {
567 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer);
568 if (source_referent != nullptr) {
569 if (java_lang_Class::is_instance(source_referent)) {
570 // When the source object points to a "real" mirror, the buffered object should point
571 // to the "scratch" mirror, which has all unarchivable fields scrubbed (to be reinstated
572 // at run time).
573 source_referent = HeapShared::scratch_java_mirror(source_referent);
574 assert(source_referent != nullptr, "must be");
575 }
576 oop request_referent = source_obj_to_requested_obj(source_referent);
577 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
578 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
579 }
580 }
581
582 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
583 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
584 address requested_region_bottom;
585
586 assert(request_p >= (T*)_requested_bottom, "sanity");
587 assert(request_p < (T*)_requested_top, "sanity");
588 requested_region_bottom = _requested_bottom;
589
590 // Mark the pointer in the oopmap
591 T* region_bottom = (T*)requested_region_bottom;
592 assert(request_p >= region_bottom, "must be");
593 BitMap::idx_t idx = request_p - region_bottom;
594 assert(idx < oopmap->size(), "overflow");
595 oopmap->set_bit(idx);
596 }
597
598 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
599 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
600 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
601 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
602
603 oop fake_oop = cast_to_oop(buffered_addr);
604 if (UseCompactObjectHeaders) {
605 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk));
606 } else {
607 fake_oop->set_narrow_klass(nk);
608 }
609
610 if (src_obj == nullptr) {
611 return;
612 }
613 // We need to retain the identity_hash, because it may have been used by some hashtables
614 // in the shared heap.
615 if (!src_obj->fast_no_hash_check()) {
616 intptr_t src_hash = src_obj->identity_hash();
617 if (UseCompactObjectHeaders) {
618 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
619 } else {
620 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
621 }
622 assert(fake_oop->mark().is_unlocked(), "sanity");
623
624 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
625 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
626 }
627 // Strip age bits.
628 fake_oop->set_mark(fake_oop->mark().set_age(0));
629 }
630
631 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
632 oop _src_obj;
633 address _buffered_obj;
634 CHeapBitMap* _oopmap;
635
636 public:
637 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
638 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) {}
639
640 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
641 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
642
643 private:
644 template <class T> void do_oop_work(T *p) {
645 size_t field_offset = pointer_delta(p, _src_obj, sizeof(char));
646 ArchiveHeapWriter::relocate_field_in_buffer<T>((T*)(_buffered_obj + field_offset), _oopmap);
647 }
648 };
649
650 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
651 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
652 size_t start = bitmap->find_first_set_bit(0);
653 size_t end = bitmap->size();
654 log_info(cds)("%s = " SIZE_FORMAT_W(7) " ... " SIZE_FORMAT_W(7) " (%3zu%% ... %3zu%% = %3zu%%)", which,
655 start, end,
656 start * 100 / total_bits,
657 end * 100 / total_bits,
658 (end - start) * 100 / total_bits);
659 }
660
661 // Update all oop fields embedded in the buffered objects
662 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
663 ArchiveHeapInfo* heap_info) {
664 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
665 size_t heap_region_byte_size = _buffer_used;
666 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
667
668 for (int i = 0; i < _source_objs_order->length(); i++) {
669 int src_obj_index = _source_objs_order->at(i)._index;
670 oop src_obj = _source_objs->at(src_obj_index);
671 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj);
672 assert(info != nullptr, "must be");
673 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
674 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
675 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
676 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
677 src_obj->oop_iterate(&relocator);
678 };
679
680 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
681 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
682 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
683 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx);
684
685 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset);
686 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass());
687 address buffered_obj = offset_to_buffered_address<address>(seg_offset);
688 int length = _heap_root_segments.size_in_elems(seg_idx);
689
690 if (UseCompressedOops) {
691 for (int i = 0; i < length; i++) {
692 narrowOop* addr = (narrowOop*)(buffered_obj + objArrayOopDesc::obj_at_offset<narrowOop>(i));
693 relocate_field_in_buffer<narrowOop>(addr, heap_info->oopmap());
694 }
695 } else {
696 for (int i = 0; i < length; i++) {
697 oop* addr = (oop*)(buffered_obj + objArrayOopDesc::obj_at_offset<oop>(i));
698 relocate_field_in_buffer<oop>(addr, heap_info->oopmap());
699 }
700 }
701 }
702
703 compute_ptrmap(heap_info);
704
705 size_t total_bytes = (size_t)_buffer->length();
706 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
707 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
708 }
709
710 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
711 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
712 if (ptr != nullptr) {
713 NativePointerInfo info;
714 info._src_obj = src_obj;
715 info._field_offset = field_offset;
716 _native_pointers->append(info);
717 if (!ArchiveBuilder::current()->has_been_archived((address)ptr)) {
718 // Currently we supporting marking of only Method and Klass, both of which are
719 // subtypes of MetaData.
720 ResourceMark rm;
721 log_error(cds, heap)("Native pointer %p is not archived", ptr);
722 if (((Metadata*)ptr)->is_method()) {
723 log_error(cds, heap)("Method: %s", ((Method*)ptr)->external_name());
724 } else {
725 assert(((Metadata*)ptr)->is_klass(), "must be");
726 log_error(cds, heap)("Klass: %s", ((Klass*)ptr)->external_name());
727 }
728 HeapShared::exit_on_error();
729 }
730 HeapShared::set_has_native_pointers(src_obj);
731 _num_native_ptrs ++;
732 }
733 }
734
735 // Do we have a jlong/jint field that's actually a pointer to a MetaspaceObj?
736 bool ArchiveHeapWriter::is_marked_as_native_pointer(ArchiveHeapInfo* heap_info, oop src_obj, int field_offset) {
737 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
738 assert(p != nullptr, "must be");
739
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((Metadata**)_requested_bottom <= requested_field_addr && requested_field_addr < (Metadata**) _requested_top, "range check");
744
745 BitMap::idx_t idx = requested_field_addr - (Metadata**) _requested_bottom;
746 // Leading zeros have been removed so some addresses may not be in the ptrmap
747 size_t start_pos = FileMapInfo::current_info()->heap_ptrmap_start_pos();
748 if (idx < start_pos) {
749 return false;
750 } else {
751 idx -= start_pos;
752 }
753 return (idx < heap_info->ptrmap()->size()) && (heap_info->ptrmap()->at(idx) == true);
754 }
755
756 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) {
757 int num_non_null_ptrs = 0;
758 Metadata** bottom = (Metadata**) _requested_bottom;
759 Metadata** top = (Metadata**) _requested_top; // exclusive
760 heap_info->ptrmap()->resize(top - bottom);
761
762 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
763 for (int i = 0; i < _native_pointers->length(); i++) {
764 NativePointerInfo info = _native_pointers->at(i);
765 oop src_obj = info._src_obj;
766 int field_offset = info._field_offset;
767 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj);
768 // requested_field_addr = the address of this field in the requested space
769 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
770 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
771 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
772
773 // Mark this field in the bitmap
774 BitMap::idx_t idx = requested_field_addr - bottom;
775 heap_info->ptrmap()->set_bit(idx);
776 num_non_null_ptrs ++;
777 max_idx = MAX2(max_idx, idx);
778
779 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
780 // this address if the RO/RW regions are mapped at the default location).
781
782 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
783 Metadata* native_ptr = *buffered_field_addr;
784 guarantee(native_ptr != nullptr, "sanity");
785 guarantee(ArchiveBuilder::current()->has_been_buffered((address)native_ptr),
786 "Metadata %p should have been archived", native_ptr);
787
788 if (RegeneratedClasses::has_been_regenerated((address)native_ptr)) {
789 native_ptr = (Metadata*)RegeneratedClasses::get_regenerated_object((address)native_ptr);
790 }
791
792 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
793 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
794 *buffered_field_addr = (Metadata*)requested_native_ptr;
795 }
796
797 heap_info->ptrmap()->resize(max_idx + 1);
798 log_info(cds, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (" SIZE_FORMAT " bits)",
799 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
800 }
801
802 #endif // INCLUDE_CDS_JAVA_HEAP