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