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