1 /* 2 * Copyright (c) 2023, 2025, 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 "cds/aotReferenceObjSupport.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/modules.hpp" 33 #include "classfile/systemDictionary.hpp" 34 #include "gc/shared/collectedHeap.hpp" 35 #include "memory/iterator.inline.hpp" 36 #include "memory/oopFactory.hpp" 37 #include "memory/universe.hpp" 38 #include "oops/compressedOops.hpp" 39 #include "oops/objArrayOop.inline.hpp" 40 #include "oops/oop.inline.hpp" 41 #include "oops/oopHandle.inline.hpp" 42 #include "oops/typeArrayKlass.hpp" 43 #include "oops/typeArrayOop.hpp" 44 #include "runtime/java.hpp" 45 #include "runtime/mutexLocker.hpp" 46 #include "utilities/bitMap.inline.hpp" 47 #if INCLUDE_G1GC 48 #include "gc/g1/g1CollectedHeap.hpp" 49 #include "gc/g1/g1HeapRegion.hpp" 50 #endif 51 52 #if INCLUDE_CDS_JAVA_HEAP 53 54 GrowableArrayCHeap<u1, mtClassShared>* ArchiveHeapWriter::_buffer = nullptr; 55 56 // The following are offsets from buffer_bottom() 57 size_t ArchiveHeapWriter::_buffer_used; 58 59 // Heap root segments 60 HeapRootSegments ArchiveHeapWriter::_heap_root_segments; 61 62 address ArchiveHeapWriter::_requested_bottom; 63 address ArchiveHeapWriter::_requested_top; 64 65 GrowableArrayCHeap<ArchiveHeapWriter::NativePointerInfo, mtClassShared>* ArchiveHeapWriter::_native_pointers; 66 GrowableArrayCHeap<oop, mtClassShared>* ArchiveHeapWriter::_source_objs; 67 GrowableArrayCHeap<ArchiveHeapWriter::HeapObjOrder, mtClassShared>* ArchiveHeapWriter::_source_objs_order; 68 69 ArchiveHeapWriter::BufferOffsetToSourceObjectTable* 70 ArchiveHeapWriter::_buffer_offset_to_source_obj_table = nullptr; 71 72 73 typedef HashTable< 74 size_t, // offset of a filler from ArchiveHeapWriter::buffer_bottom() 75 size_t, // size of this filler (in bytes) 76 127, // prime number 77 AnyObj::C_HEAP, 78 mtClassShared> FillersTable; 79 static FillersTable* _fillers; 80 static int _num_native_ptrs = 0; 81 82 void ArchiveHeapWriter::init() { 83 if (CDSConfig::is_dumping_heap()) { 84 Universe::heap()->collect(GCCause::_java_lang_system_gc); 85 86 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M); 87 _fillers = new FillersTable(); 88 _requested_bottom = nullptr; 89 _requested_top = nullptr; 90 91 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048); 92 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000); 93 94 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be"); 95 } 96 } 97 98 void ArchiveHeapWriter::add_source_obj(oop src_obj) { 99 _source_objs->append(src_obj); 100 } 101 102 void ArchiveHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots, 103 ArchiveHeapInfo* heap_info) { 104 assert(CDSConfig::is_dumping_heap(), "sanity"); 105 allocate_buffer(); 106 copy_source_objs_to_buffer(roots); 107 set_requested_address(heap_info); 108 relocate_embedded_oops(roots, heap_info); 109 } 110 111 bool ArchiveHeapWriter::is_too_large_to_archive(oop o) { 112 return is_too_large_to_archive(o->size()); 113 } 114 115 bool ArchiveHeapWriter::is_string_too_large_to_archive(oop string) { 116 typeArrayOop value = java_lang_String::value_no_keepalive(string); 117 return is_too_large_to_archive(value); 118 } 119 120 bool ArchiveHeapWriter::is_too_large_to_archive(size_t size) { 121 assert(size > 0, "no zero-size object"); 122 assert(size * HeapWordSize > size, "no overflow"); 123 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive"); 124 125 size_t byte_size = size * HeapWordSize; 126 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) { 127 return true; 128 } else { 129 return false; 130 } 131 } 132 133 // Various lookup functions between source_obj, buffered_obj and requested_obj 134 bool ArchiveHeapWriter::is_in_requested_range(oop o) { 135 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized"); 136 address a = cast_from_oop<address>(o); 137 return (_requested_bottom <= a && a < _requested_top); 138 } 139 140 oop ArchiveHeapWriter::requested_obj_from_buffer_offset(size_t offset) { 141 oop req_obj = cast_to_oop(_requested_bottom + offset); 142 assert(is_in_requested_range(req_obj), "must be"); 143 return req_obj; 144 } 145 146 oop ArchiveHeapWriter::source_obj_to_requested_obj(oop src_obj) { 147 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 148 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj); 149 if (p != nullptr) { 150 return requested_obj_from_buffer_offset(p->buffer_offset()); 151 } else { 152 return nullptr; 153 } 154 } 155 156 oop ArchiveHeapWriter::buffered_addr_to_source_obj(address buffered_addr) { 157 oop* p = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr)); 158 if (p != nullptr) { 159 return *p; 160 } else { 161 return nullptr; 162 } 163 } 164 165 Klass* ArchiveHeapWriter::real_klass_of_buffered_oop(address buffered_addr) { 166 oop p = buffered_addr_to_source_obj(buffered_addr); 167 if (p != nullptr) { 168 return p->klass(); 169 } else if (get_filler_size_at(buffered_addr) > 0) { 170 return Universe::fillerArrayKlass(); 171 } else { 172 // This is one of the root segments 173 return Universe::objectArrayKlass(); 174 } 175 } 176 177 size_t ArchiveHeapWriter::size_of_buffered_oop(address buffered_addr) { 178 oop p = buffered_addr_to_source_obj(buffered_addr); 179 if (p != nullptr) { 180 return p->size(); 181 } 182 183 size_t nbytes = get_filler_size_at(buffered_addr); 184 if (nbytes > 0) { 185 assert((nbytes % BytesPerWord) == 0, "should be aligned"); 186 return nbytes / BytesPerWord; 187 } 188 189 address hrs = buffer_bottom(); 190 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) { 191 nbytes = _heap_root_segments.size_in_bytes(seg_idx); 192 if (hrs == buffered_addr) { 193 assert((nbytes % BytesPerWord) == 0, "should be aligned"); 194 return nbytes / BytesPerWord; 195 } 196 hrs += nbytes; 197 } 198 199 ShouldNotReachHere(); 200 return 0; 201 } 202 203 address ArchiveHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) { 204 return _requested_bottom + buffered_address_to_offset(buffered_addr); 205 } 206 207 address ArchiveHeapWriter::requested_address() { 208 assert(_buffer != nullptr, "must be initialized"); 209 return _requested_bottom; 210 } 211 212 void ArchiveHeapWriter::allocate_buffer() { 213 int initial_buffer_size = 100000; 214 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size); 215 _buffer_used = 0; 216 ensure_buffer_space(1); // so that buffer_bottom() works 217 } 218 219 void ArchiveHeapWriter::ensure_buffer_space(size_t min_bytes) { 220 // We usually have very small heaps. If we get a huge one it's probably caused by a bug. 221 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects"); 222 _buffer->at_grow(to_array_index(min_bytes)); 223 } 224 225 objArrayOop ArchiveHeapWriter::allocate_root_segment(size_t offset, int element_count) { 226 HeapWord* mem = offset_to_buffered_address<HeapWord *>(offset); 227 memset(mem, 0, objArrayOopDesc::object_size(element_count)); 228 229 // The initialization code is copied from MemAllocator::finish and ObjArrayAllocator::initialize. 230 if (UseCompactObjectHeaders) { 231 oopDesc::release_set_mark(mem, Universe::objectArrayKlass()->prototype_header()); 232 } else { 233 oopDesc::set_mark(mem, markWord::prototype()); 234 oopDesc::release_set_klass(mem, Universe::objectArrayKlass()); 235 } 236 arrayOopDesc::set_length(mem, element_count); 237 return objArrayOop(cast_to_oop(mem)); 238 } 239 240 void ArchiveHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) { 241 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap! 242 if (UseCompressedOops) { 243 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root); 244 } else { 245 *segment->obj_at_addr<oop>(index) = root; 246 } 247 } 248 249 void ArchiveHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) { 250 // Depending on the number of classes we are archiving, a single roots array may be 251 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which 252 // allows us to chop the large array into a series of "segments". Current layout 253 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end 254 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT. 255 // This is simple and efficient. We do not need filler objects anywhere between the segments, 256 // or immediately after the last segment. This allows starting the object dump immediately 257 // after the roots. 258 259 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0, 260 "Pre-condition: Roots start at aligned boundary: %zu", _buffer_used); 261 262 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize); 263 assert(objArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT, 264 "Should match exactly"); 265 266 HeapRootSegments segments(_buffer_used, 267 roots->length(), 268 MIN_GC_REGION_ALIGNMENT, 269 max_elem_count); 270 271 int root_index = 0; 272 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) { 273 int size_elems = segments.size_in_elems(seg_idx); 274 size_t size_bytes = segments.size_in_bytes(seg_idx); 275 276 size_t oop_offset = _buffer_used; 277 _buffer_used = oop_offset + size_bytes; 278 ensure_buffer_space(_buffer_used); 279 280 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0, 281 "Roots segment %zu start is not aligned: %zu", 282 segments.count(), oop_offset); 283 284 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems); 285 for (int i = 0; i < size_elems; i++) { 286 root_segment_at_put(seg_oop, i, roots->at(root_index++)); 287 } 288 289 log_info(aot, heap)("archived obj root segment [%d] = %zu bytes, obj = " PTR_FORMAT, 290 size_elems, size_bytes, p2i(seg_oop)); 291 } 292 293 assert(root_index == roots->length(), "Post-condition: All roots are handled"); 294 295 _heap_root_segments = segments; 296 } 297 298 // The goal is to sort the objects in increasing order of: 299 // - objects that have only oop pointers 300 // - objects that have both native and oop pointers 301 // - objects that have only native pointers 302 // - objects that have no pointers 303 static int oop_sorting_rank(oop o) { 304 bool has_oop_ptr, has_native_ptr; 305 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr); 306 307 if (has_oop_ptr) { 308 if (!has_native_ptr) { 309 return 0; 310 } else { 311 return 1; 312 } 313 } else { 314 if (has_native_ptr) { 315 return 2; 316 } else { 317 return 3; 318 } 319 } 320 } 321 322 int ArchiveHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) { 323 int rank_a = a->_rank; 324 int rank_b = b->_rank; 325 326 if (rank_a != rank_b) { 327 return rank_a - rank_b; 328 } else { 329 // If they are the same rank, sort them by their position in the _source_objs array 330 return a->_index - b->_index; 331 } 332 } 333 334 void ArchiveHeapWriter::sort_source_objs() { 335 log_info(aot)("sorting heap objects"); 336 int len = _source_objs->length(); 337 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len); 338 339 for (int i = 0; i < len; i++) { 340 oop o = _source_objs->at(i); 341 int rank = oop_sorting_rank(o); 342 HeapObjOrder os = {i, rank}; 343 _source_objs_order->append(os); 344 } 345 log_info(aot)("computed ranks"); 346 _source_objs_order->sort(compare_objs_by_oop_fields); 347 log_info(aot)("sorting heap objects done"); 348 } 349 350 void ArchiveHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) { 351 // There could be multiple root segments, which we want to be aligned by region. 352 // Putting them ahead of objects makes sure we waste no space. 353 copy_roots_to_buffer(roots); 354 355 sort_source_objs(); 356 for (int i = 0; i < _source_objs_order->length(); i++) { 357 int src_obj_index = _source_objs_order->at(i)._index; 358 oop src_obj = _source_objs->at(src_obj_index); 359 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj); 360 assert(info != nullptr, "must be"); 361 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj); 362 info->set_buffer_offset(buffer_offset); 363 364 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, src_obj); 365 _buffer_offset_to_source_obj_table->maybe_grow(); 366 367 if (java_lang_Module::is_instance(src_obj)) { 368 Modules::check_archived_module_oop(src_obj); 369 } 370 } 371 372 log_info(aot)("Size of heap region = %zu bytes, %d objects, %d roots, %d native ptrs", 373 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs); 374 } 375 376 size_t ArchiveHeapWriter::filler_array_byte_size(int length) { 377 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize; 378 return byte_size; 379 } 380 381 int ArchiveHeapWriter::filler_array_length(size_t fill_bytes) { 382 assert(is_object_aligned(fill_bytes), "must be"); 383 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 384 385 int initial_length = to_array_length(fill_bytes / elemSize); 386 for (int length = initial_length; length >= 0; length --) { 387 size_t array_byte_size = filler_array_byte_size(length); 388 if (array_byte_size == fill_bytes) { 389 return length; 390 } 391 } 392 393 ShouldNotReachHere(); 394 return -1; 395 } 396 397 HeapWord* ArchiveHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) { 398 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses"); 399 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass 400 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used); 401 memset(mem, 0, fill_bytes); 402 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak); 403 if (UseCompactObjectHeaders) { 404 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk)); 405 } else { 406 oopDesc::set_mark(mem, markWord::prototype()); 407 cast_to_oop(mem)->set_narrow_klass(nk); 408 } 409 arrayOopDesc::set_length(mem, array_length); 410 return mem; 411 } 412 413 void ArchiveHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) { 414 // We fill only with arrays (so we don't need to use a single HeapWord filler if the 415 // leftover space is smaller than a zero-sized array object). Therefore, we need to 416 // make sure there's enough space of min_filler_byte_size in the current region after 417 // required_byte_size has been allocated. If not, fill the remainder of the current 418 // region. 419 size_t min_filler_byte_size = filler_array_byte_size(0); 420 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size; 421 422 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT); 423 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT); 424 425 if (cur_min_region_bottom != next_min_region_bottom) { 426 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way 427 // we can map the region in any region-based collector. 428 assert(next_min_region_bottom > cur_min_region_bottom, "must be"); 429 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT, 430 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT); 431 432 const size_t filler_end = next_min_region_bottom; 433 const size_t fill_bytes = filler_end - _buffer_used; 434 assert(fill_bytes > 0, "must be"); 435 ensure_buffer_space(filler_end); 436 437 int array_length = filler_array_length(fill_bytes); 438 log_info(aot, heap)("Inserting filler obj array of %d elements (%zu bytes total) @ buffer offset %zu", 439 array_length, fill_bytes, _buffer_used); 440 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes); 441 _buffer_used = filler_end; 442 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes); 443 } 444 } 445 446 size_t ArchiveHeapWriter::get_filler_size_at(address buffered_addr) { 447 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr)); 448 if (p != nullptr) { 449 assert(*p > 0, "filler must be larger than zero bytes"); 450 return *p; 451 } else { 452 return 0; // buffered_addr is not a filler 453 } 454 } 455 456 template <typename T> 457 void update_buffered_object_field(address buffered_obj, int field_offset, T value) { 458 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset); 459 *field_addr = value; 460 } 461 462 size_t ArchiveHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) { 463 assert(!is_too_large_to_archive(src_obj), "already checked"); 464 size_t byte_size = src_obj->size() * HeapWordSize; 465 assert(byte_size > 0, "no zero-size objects"); 466 467 // For region-based collectors such as G1, the archive heap may be mapped into 468 // multiple regions. We need to make sure that we don't have an object that can possible 469 // span across two regions. 470 maybe_fill_gc_region_gap(byte_size); 471 472 size_t new_used = _buffer_used + byte_size; 473 assert(new_used > _buffer_used, "no wrap around"); 474 475 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT); 476 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT); 477 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries"); 478 479 ensure_buffer_space(new_used); 480 481 address from = cast_from_oop<address>(src_obj); 482 address to = offset_to_buffered_address<address>(_buffer_used); 483 assert(is_object_aligned(_buffer_used), "sanity"); 484 assert(is_object_aligned(byte_size), "sanity"); 485 memcpy(to, from, byte_size); 486 487 // These native pointers will be restored explicitly at run time. 488 if (java_lang_Module::is_instance(src_obj)) { 489 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr); 490 } else if (java_lang_ClassLoader::is_instance(src_obj)) { 491 #ifdef ASSERT 492 // We only archive these loaders 493 if (src_obj != SystemDictionary::java_platform_loader() && 494 src_obj != SystemDictionary::java_system_loader()) { 495 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be"); 496 } 497 #endif 498 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr); 499 } 500 501 size_t buffered_obj_offset = _buffer_used; 502 _buffer_used = new_used; 503 504 return buffered_obj_offset; 505 } 506 507 void ArchiveHeapWriter::set_requested_address(ArchiveHeapInfo* info) { 508 assert(!info->is_used(), "only set once"); 509 510 size_t heap_region_byte_size = _buffer_used; 511 assert(heap_region_byte_size > 0, "must archived at least one object!"); 512 513 if (UseCompressedOops) { 514 if (UseG1GC) { 515 address heap_end = (address)G1CollectedHeap::heap()->reserved().end(); 516 log_info(aot, heap)("Heap end = %p", heap_end); 517 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes); 518 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT); 519 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity"); 520 } else { 521 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT); 522 } 523 } else { 524 // We always write the objects as if the heap started at this address. This 525 // makes the contents of the archive heap deterministic. 526 // 527 // Note that at runtime, the heap address is selected by the OS, so the archive 528 // heap will not be mapped at 0x10000000, and the contents need to be patched. 529 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT); 530 } 531 532 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity"); 533 534 _requested_top = _requested_bottom + _buffer_used; 535 536 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0), 537 offset_to_buffered_address<HeapWord*>(_buffer_used))); 538 info->set_heap_root_segments(_heap_root_segments); 539 } 540 541 // Oop relocation 542 543 template <typename T> T* ArchiveHeapWriter::requested_addr_to_buffered_addr(T* p) { 544 assert(is_in_requested_range(cast_to_oop(p)), "must be"); 545 546 address addr = address(p); 547 assert(addr >= _requested_bottom, "must be"); 548 size_t offset = addr - _requested_bottom; 549 return offset_to_buffered_address<T*>(offset); 550 } 551 552 template <typename T> oop ArchiveHeapWriter::load_source_oop_from_buffer(T* buffered_addr) { 553 oop o = load_oop_from_buffer(buffered_addr); 554 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop"); 555 return o; 556 } 557 558 template <typename T> void ArchiveHeapWriter::store_requested_oop_in_buffer(T* buffered_addr, 559 oop request_oop) { 560 assert(is_in_requested_range(request_oop), "must be"); 561 store_oop_in_buffer(buffered_addr, request_oop); 562 } 563 564 inline void ArchiveHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) { 565 *buffered_addr = requested_obj; 566 } 567 568 inline void ArchiveHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) { 569 narrowOop val = CompressedOops::encode_not_null(requested_obj); 570 *buffered_addr = val; 571 } 572 573 oop ArchiveHeapWriter::load_oop_from_buffer(oop* buffered_addr) { 574 return *buffered_addr; 575 } 576 577 oop ArchiveHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) { 578 return CompressedOops::decode(*buffered_addr); 579 } 580 581 template <typename T> void ArchiveHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, CHeapBitMap* oopmap) { 582 oop source_referent = load_source_oop_from_buffer<T>(field_addr_in_buffer); 583 if (source_referent != nullptr) { 584 if (java_lang_Class::is_instance(source_referent)) { 585 Klass* k = java_lang_Class::as_Klass(source_referent); 586 if (RegeneratedClasses::has_been_regenerated(k)) { 587 source_referent = RegeneratedClasses::get_regenerated_object(k)->java_mirror(); 588 } 589 // When the source object points to a "real" mirror, the buffered object should point 590 // to the "scratch" mirror, which has all unarchivable fields scrubbed (to be reinstated 591 // at run time). 592 source_referent = HeapShared::scratch_java_mirror(source_referent); 593 assert(source_referent != nullptr, "must be"); 594 } 595 oop request_referent = source_obj_to_requested_obj(source_referent); 596 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent); 597 mark_oop_pointer<T>(field_addr_in_buffer, oopmap); 598 } 599 } 600 601 template <typename T> void ArchiveHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) { 602 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr)); 603 address requested_region_bottom; 604 605 assert(request_p >= (T*)_requested_bottom, "sanity"); 606 assert(request_p < (T*)_requested_top, "sanity"); 607 requested_region_bottom = _requested_bottom; 608 609 // Mark the pointer in the oopmap 610 T* region_bottom = (T*)requested_region_bottom; 611 assert(request_p >= region_bottom, "must be"); 612 BitMap::idx_t idx = request_p - region_bottom; 613 assert(idx < oopmap->size(), "overflow"); 614 oopmap->set_bit(idx); 615 } 616 617 void ArchiveHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) { 618 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses"); 619 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass); 620 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj)); 621 622 oop fake_oop = cast_to_oop(buffered_addr); 623 if (UseCompactObjectHeaders) { 624 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk)); 625 } else { 626 fake_oop->set_narrow_klass(nk); 627 } 628 629 if (src_obj == nullptr) { 630 return; 631 } 632 // We need to retain the identity_hash, because it may have been used by some hashtables 633 // in the shared heap. 634 if (!src_obj->fast_no_hash_check()) { 635 intptr_t src_hash = src_obj->identity_hash(); 636 if (UseCompactObjectHeaders) { 637 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash)); 638 } else { 639 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash)); 640 } 641 assert(fake_oop->mark().is_unlocked(), "sanity"); 642 643 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash()); 644 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash); 645 } 646 // Strip age bits. 647 fake_oop->set_mark(fake_oop->mark().set_age(0)); 648 } 649 650 class ArchiveHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure { 651 oop _src_obj; 652 address _buffered_obj; 653 CHeapBitMap* _oopmap; 654 bool _is_java_lang_ref; 655 public: 656 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) : 657 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) 658 { 659 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(src_obj); 660 } 661 662 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); } 663 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); } 664 665 private: 666 template <class T> void do_oop_work(T *p) { 667 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_src_obj)); 668 T* field_addr = (T*)(_buffered_obj + field_offset); 669 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) { 670 // Do not copy these fields. Set them to null 671 *field_addr = (T)0x0; 672 } else { 673 ArchiveHeapWriter::relocate_field_in_buffer<T>(field_addr, _oopmap); 674 } 675 } 676 }; 677 678 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) { 679 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end). 680 size_t start = bitmap->find_first_set_bit(0); 681 size_t end = bitmap->size(); 682 log_info(aot)("%s = %7zu ... %7zu (%3zu%% ... %3zu%% = %3zu%%)", which, 683 start, end, 684 start * 100 / total_bits, 685 end * 100 / total_bits, 686 (end - start) * 100 / total_bits); 687 } 688 689 // Update all oop fields embedded in the buffered objects 690 void ArchiveHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots, 691 ArchiveHeapInfo* heap_info) { 692 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 693 size_t heap_region_byte_size = _buffer_used; 694 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit); 695 696 for (int i = 0; i < _source_objs_order->length(); i++) { 697 int src_obj_index = _source_objs_order->at(i)._index; 698 oop src_obj = _source_objs->at(src_obj_index); 699 HeapShared::CachedOopInfo* info = HeapShared::archived_object_cache()->get(src_obj); 700 assert(info != nullptr, "must be"); 701 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset()); 702 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass()); 703 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset()); 704 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap()); 705 src_obj->oop_iterate(&relocator); 706 }; 707 708 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and 709 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it. 710 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) { 711 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx); 712 713 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset); 714 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass()); 715 address buffered_obj = offset_to_buffered_address<address>(seg_offset); 716 int length = _heap_root_segments.size_in_elems(seg_idx); 717 718 if (UseCompressedOops) { 719 for (int i = 0; i < length; i++) { 720 narrowOop* addr = (narrowOop*)(buffered_obj + objArrayOopDesc::obj_at_offset<narrowOop>(i)); 721 relocate_field_in_buffer<narrowOop>(addr, heap_info->oopmap()); 722 } 723 } else { 724 for (int i = 0; i < length; i++) { 725 oop* addr = (oop*)(buffered_obj + objArrayOopDesc::obj_at_offset<oop>(i)); 726 relocate_field_in_buffer<oop>(addr, heap_info->oopmap()); 727 } 728 } 729 } 730 731 compute_ptrmap(heap_info); 732 733 size_t total_bytes = (size_t)_buffer->length(); 734 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop))); 735 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address)); 736 } 737 738 void ArchiveHeapWriter::mark_native_pointer(oop src_obj, int field_offset) { 739 Metadata* ptr = src_obj->metadata_field_acquire(field_offset); 740 if (ptr != nullptr) { 741 NativePointerInfo info; 742 info._src_obj = src_obj; 743 info._field_offset = field_offset; 744 _native_pointers->append(info); 745 HeapShared::set_has_native_pointers(src_obj); 746 _num_native_ptrs ++; 747 } 748 } 749 750 void ArchiveHeapWriter::compute_ptrmap(ArchiveHeapInfo* heap_info) { 751 int num_non_null_ptrs = 0; 752 Metadata** bottom = (Metadata**) _requested_bottom; 753 Metadata** top = (Metadata**) _requested_top; // exclusive 754 heap_info->ptrmap()->resize(top - bottom); 755 756 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small 757 for (int i = 0; i < _native_pointers->length(); i++) { 758 NativePointerInfo info = _native_pointers->at(i); 759 oop src_obj = info._src_obj; 760 int field_offset = info._field_offset; 761 HeapShared::CachedOopInfo* p = HeapShared::archived_object_cache()->get(src_obj); 762 // requested_field_addr = the address of this field in the requested space 763 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset()); 764 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset); 765 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check"); 766 767 // Mark this field in the bitmap 768 BitMap::idx_t idx = requested_field_addr - bottom; 769 heap_info->ptrmap()->set_bit(idx); 770 num_non_null_ptrs ++; 771 max_idx = MAX2(max_idx, idx); 772 773 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have 774 // this address if the RO/RW regions are mapped at the default location). 775 776 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr); 777 Metadata* native_ptr = *buffered_field_addr; 778 guarantee(native_ptr != nullptr, "sanity"); 779 780 if (RegeneratedClasses::has_been_regenerated(native_ptr)) { 781 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr); 782 } 783 784 guarantee(ArchiveBuilder::current()->has_been_archived((address)native_ptr), 785 "Metadata %p should have been archived", native_ptr); 786 787 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr); 788 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr); 789 *buffered_field_addr = (Metadata*)requested_native_ptr; 790 } 791 792 heap_info->ptrmap()->resize(max_idx + 1); 793 log_info(aot, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (%zu bits)", 794 num_non_null_ptrs, size_t(heap_info->ptrmap()->size())); 795 } 796 797 #endif // INCLUDE_CDS_JAVA_HEAP