1 /* 2 * Copyright (c) 2023, 2026, 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/aotMappedHeap.hpp" 26 #include "cds/aotMappedHeapWriter.hpp" 27 #include "cds/aotReferenceObjSupport.hpp" 28 #include "cds/cdsConfig.hpp" 29 #include "cds/filemap.hpp" 30 #include "cds/heapShared.inline.hpp" 31 #include "cds/regeneratedClasses.hpp" 32 #include "classfile/javaClasses.hpp" 33 #include "classfile/modules.hpp" 34 #include "classfile/systemDictionary.hpp" 35 #include "gc/shared/collectedHeap.hpp" 36 #include "memory/allocation.inline.hpp" 37 #include "memory/iterator.inline.hpp" 38 #include "memory/oopFactory.hpp" 39 #include "memory/universe.hpp" 40 #include "oops/compressedOops.hpp" 41 #include "oops/objArrayOop.inline.hpp" 42 #include "oops/oop.inline.hpp" 43 #include "oops/oopHandle.inline.hpp" 44 #include "oops/typeArrayKlass.hpp" 45 #include "oops/typeArrayOop.hpp" 46 #include "runtime/arguments.hpp" 47 #include "runtime/java.hpp" 48 #include "runtime/mutexLocker.hpp" 49 #include "utilities/bitMap.inline.hpp" 50 #if INCLUDE_G1GC 51 #include "gc/g1/g1CollectedHeap.hpp" 52 #include "gc/g1/g1HeapRegion.hpp" 53 #endif 54 55 #if INCLUDE_CDS_JAVA_HEAP 56 57 GrowableArrayCHeap<u1, mtClassShared>* AOTMappedHeapWriter::_buffer = nullptr; 58 59 bool AOTMappedHeapWriter::_is_writing_deterministic_heap = false; 60 size_t AOTMappedHeapWriter::_buffer_used; 61 62 // Heap root segments 63 HeapRootSegments AOTMappedHeapWriter::_heap_root_segments; 64 65 address AOTMappedHeapWriter::_requested_bottom; 66 address AOTMappedHeapWriter::_requested_top; 67 68 static size_t _num_strings = 0; 69 static size_t _string_bytes = 0; 70 static size_t _num_packages = 0; 71 static size_t _num_protection_domains = 0; 72 73 GrowableArrayCHeap<AOTMappedHeapWriter::NativePointerInfo, mtClassShared>* AOTMappedHeapWriter::_native_pointers; 74 GrowableArrayCHeap<oop, mtClassShared>* AOTMappedHeapWriter::_source_objs; 75 GrowableArrayCHeap<AOTMappedHeapWriter::HeapObjOrder, mtClassShared>* AOTMappedHeapWriter::_source_objs_order; 76 77 AOTMappedHeapWriter::BufferOffsetToSourceObjectTable* 78 AOTMappedHeapWriter::_buffer_offset_to_source_obj_table = nullptr; 79 80 typedef HashTable< 81 size_t, // offset of a filler from AOTMappedHeapWriter::buffer_bottom() 82 size_t, // size of this filler (in bytes) 83 127, // prime number 84 AnyObj::C_HEAP, 85 mtClassShared> FillersTable; 86 static FillersTable* _fillers; 87 static int _num_native_ptrs = 0; 88 89 void AOTMappedHeapWriter::init() { 90 if (CDSConfig::is_dumping_heap()) { 91 Universe::heap()->collect(GCCause::_java_lang_system_gc); 92 93 _buffer_offset_to_source_obj_table = new (mtClassShared) BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M); 94 _fillers = new (mtClassShared) FillersTable(); 95 _requested_bottom = nullptr; 96 _requested_top = nullptr; 97 98 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048); 99 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000); 100 101 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be"); 102 103 if (CDSConfig::old_cds_flags_used()) { 104 // With the old CDS workflow, we can guatantee determninistic output: given 105 // the same classlist file, we can generate the same static CDS archive. 106 // To ensure determinism, we always use the same compressed oop encoding 107 // (zero-based, no shift). See set_requested_address_range(). 108 _is_writing_deterministic_heap = true; 109 } else { 110 // Determninistic output is not supported by the new AOT workflow, so 111 // we don't force the (zero-based, no shift) encoding. This way, it is more 112 // likely that we can avoid oop relocation in the production run. 113 _is_writing_deterministic_heap = false; 114 } 115 } 116 } 117 118 // For AOTMappedHeapWriter::narrow_oop_{mode, base, shift}(), see comments 119 // in AOTMappedHeapWriter::set_requested_address_range(), 120 CompressedOops::Mode AOTMappedHeapWriter::narrow_oop_mode() { 121 if (is_writing_deterministic_heap()) { 122 return CompressedOops::UnscaledNarrowOop; 123 } else { 124 return CompressedOops::mode(); 125 } 126 } 127 128 address AOTMappedHeapWriter::narrow_oop_base() { 129 if (is_writing_deterministic_heap()) { 130 return nullptr; 131 } else { 132 return CompressedOops::base(); 133 } 134 } 135 136 int AOTMappedHeapWriter::narrow_oop_shift() { 137 if (is_writing_deterministic_heap()) { 138 return 0; 139 } else { 140 return CompressedOops::shift(); 141 } 142 } 143 144 void AOTMappedHeapWriter::delete_tables_with_raw_oops() { 145 delete _source_objs; 146 _source_objs = nullptr; 147 } 148 149 void AOTMappedHeapWriter::add_source_obj(oop src_obj) { 150 _source_objs->append(src_obj); 151 } 152 153 void AOTMappedHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots, 154 AOTMappedHeapInfo* heap_info) { 155 assert(CDSConfig::is_dumping_heap(), "sanity"); 156 allocate_buffer(); 157 copy_source_objs_to_buffer(roots); 158 set_requested_address_range(heap_info); 159 relocate_embedded_oops(roots, heap_info); 160 } 161 162 bool AOTMappedHeapWriter::is_too_large_to_archive(oop o) { 163 return is_too_large_to_archive(o->size()); 164 } 165 166 bool AOTMappedHeapWriter::is_string_too_large_to_archive(oop string) { 167 typeArrayOop value = java_lang_String::value_no_keepalive(string); 168 return is_too_large_to_archive(value); 169 } 170 171 bool AOTMappedHeapWriter::is_too_large_to_archive(size_t size) { 172 assert(size > 0, "no zero-size object"); 173 assert(size * HeapWordSize > size, "no overflow"); 174 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive"); 175 176 size_t byte_size = size * HeapWordSize; 177 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) { 178 return true; 179 } else { 180 return false; 181 } 182 } 183 184 // Various lookup functions between source_obj, buffered_obj and requested_obj 185 bool AOTMappedHeapWriter::is_in_requested_range(oop o) { 186 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized"); 187 address a = cast_from_oop<address>(o); 188 return (_requested_bottom <= a && a < _requested_top); 189 } 190 191 oop AOTMappedHeapWriter::requested_obj_from_buffer_offset(size_t offset) { 192 oop req_obj = cast_to_oop(_requested_bottom + offset); 193 assert(is_in_requested_range(req_obj), "must be"); 194 return req_obj; 195 } 196 197 oop AOTMappedHeapWriter::source_obj_to_requested_obj(oop src_obj) { 198 assert(CDSConfig::is_dumping_heap(), "dump-time only"); 199 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj); 200 if (p != nullptr) { 201 return requested_obj_from_buffer_offset(p->buffer_offset()); 202 } else { 203 return nullptr; 204 } 205 } 206 207 oop AOTMappedHeapWriter::buffered_addr_to_source_obj(address buffered_addr) { 208 OopHandle* oh = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr)); 209 if (oh != nullptr) { 210 return oh->resolve(); 211 } else { 212 return nullptr; 213 } 214 } 215 216 Klass* AOTMappedHeapWriter::real_klass_of_buffered_oop(address buffered_addr) { 217 oop p = buffered_addr_to_source_obj(buffered_addr); 218 if (p != nullptr) { 219 return p->klass(); 220 } else if (get_filler_size_at(buffered_addr) > 0) { 221 return Universe::fillerArrayKlass(); 222 } else { 223 // This is one of the root segments 224 return Universe::objectArrayKlass(); 225 } 226 } 227 228 size_t AOTMappedHeapWriter::size_of_buffered_oop(address buffered_addr) { 229 oop p = buffered_addr_to_source_obj(buffered_addr); 230 if (p != nullptr) { 231 return p->size(); 232 } 233 234 size_t nbytes = get_filler_size_at(buffered_addr); 235 if (nbytes > 0) { 236 assert((nbytes % BytesPerWord) == 0, "should be aligned"); 237 return nbytes / BytesPerWord; 238 } 239 240 address hrs = buffer_bottom(); 241 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) { 242 nbytes = _heap_root_segments.size_in_bytes(seg_idx); 243 if (hrs == buffered_addr) { 244 assert((nbytes % BytesPerWord) == 0, "should be aligned"); 245 return nbytes / BytesPerWord; 246 } 247 hrs += nbytes; 248 } 249 250 ShouldNotReachHere(); 251 return 0; 252 } 253 254 address AOTMappedHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) { 255 return _requested_bottom + buffered_address_to_offset(buffered_addr); 256 } 257 258 address AOTMappedHeapWriter::requested_address() { 259 assert(_buffer != nullptr, "must be initialized"); 260 return _requested_bottom; 261 } 262 263 void AOTMappedHeapWriter::allocate_buffer() { 264 int initial_buffer_size = 100000; 265 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size); 266 _buffer_used = 0; 267 ensure_buffer_space(1); // so that buffer_bottom() works 268 } 269 270 void AOTMappedHeapWriter::ensure_buffer_space(size_t min_bytes) { 271 // We usually have very small heaps. If we get a huge one it's probably caused by a bug. 272 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects"); 273 _buffer->at_grow(to_array_index(min_bytes)); 274 } 275 276 objArrayOop AOTMappedHeapWriter::allocate_root_segment(size_t offset, int element_count) { 277 HeapWord* mem = offset_to_buffered_address<HeapWord *>(offset); 278 memset(mem, 0, refArrayOopDesc::object_size(element_count)); 279 280 // The initialization code is copied from MemAllocator::finish and ObjArrayAllocator::initialize. 281 if (UseCompactObjectHeaders) { 282 oopDesc::release_set_mark(mem, Universe::objectArrayKlass()->prototype_header()); 283 } else { 284 assert(!Arguments::is_valhalla_enabled() || Universe::objectArrayKlass()->prototype_header() == markWord::prototype(), "should be the same"); 285 oopDesc::set_mark(mem, markWord::prototype()); 286 oopDesc::release_set_klass(mem, Universe::objectArrayKlass()); 287 } 288 arrayOopDesc::set_length(mem, element_count); 289 return objArrayOop(cast_to_oop(mem)); 290 } 291 292 void AOTMappedHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) { 293 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap! 294 if (UseCompressedOops) { 295 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root); 296 } else { 297 *segment->obj_at_addr<oop>(index) = root; 298 } 299 } 300 301 void AOTMappedHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) { 302 // Depending on the number of classes we are archiving, a single roots array may be 303 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which 304 // allows us to chop the large array into a series of "segments". Current layout 305 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end 306 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT. 307 // This is simple and efficient. We do not need filler objects anywhere between the segments, 308 // or immediately after the last segment. This allows starting the object dump immediately 309 // after the roots. 310 311 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0, 312 "Pre-condition: Roots start at aligned boundary: %zu", _buffer_used); 313 314 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize); 315 assert(refArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT, 316 "Should match exactly"); 317 318 HeapRootSegments segments(_buffer_used, 319 roots->length(), 320 MIN_GC_REGION_ALIGNMENT, 321 max_elem_count); 322 323 int root_index = 0; 324 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) { 325 int size_elems = segments.size_in_elems(seg_idx); 326 size_t size_bytes = segments.size_in_bytes(seg_idx); 327 328 size_t oop_offset = _buffer_used; 329 _buffer_used = oop_offset + size_bytes; 330 ensure_buffer_space(_buffer_used); 331 332 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0, 333 "Roots segment %zu start is not aligned: %zu", 334 segments.count(), oop_offset); 335 336 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems); 337 for (int i = 0; i < size_elems; i++) { 338 root_segment_at_put(seg_oop, i, roots->at(root_index++)); 339 } 340 341 log_info(aot, heap)("archived obj root segment [%d] = %zu bytes, obj = " PTR_FORMAT, 342 size_elems, size_bytes, p2i(seg_oop)); 343 } 344 345 assert(root_index == roots->length(), "Post-condition: All roots are handled"); 346 347 _heap_root_segments = segments; 348 } 349 350 // The goal is to sort the objects in increasing order of: 351 // - objects that have only oop pointers 352 // - objects that have both native and oop pointers 353 // - objects that have only native pointers 354 // - objects that have no pointers 355 static int oop_sorting_rank(oop o) { 356 bool has_oop_ptr, has_native_ptr; 357 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr); 358 359 if (has_oop_ptr) { 360 if (!has_native_ptr) { 361 return 0; 362 } else { 363 return 1; 364 } 365 } else { 366 if (has_native_ptr) { 367 return 2; 368 } else { 369 return 3; 370 } 371 } 372 } 373 374 int AOTMappedHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) { 375 int rank_a = a->_rank; 376 int rank_b = b->_rank; 377 378 if (rank_a != rank_b) { 379 return rank_a - rank_b; 380 } else { 381 // If they are the same rank, sort them by their position in the _source_objs array 382 return a->_index - b->_index; 383 } 384 } 385 386 void AOTMappedHeapWriter::sort_source_objs() { 387 log_info(aot)("sorting heap objects"); 388 int len = _source_objs->length(); 389 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len); 390 391 for (int i = 0; i < len; i++) { 392 oop o = _source_objs->at(i); 393 int rank = oop_sorting_rank(o); 394 HeapObjOrder os = {i, rank}; 395 _source_objs_order->append(os); 396 } 397 log_info(aot)("computed ranks"); 398 _source_objs_order->sort(compare_objs_by_oop_fields); 399 log_info(aot)("sorting heap objects done"); 400 } 401 402 void AOTMappedHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) { 403 // There could be multiple root segments, which we want to be aligned by region. 404 // Putting them ahead of objects makes sure we waste no space. 405 copy_roots_to_buffer(roots); 406 407 sort_source_objs(); 408 for (int i = 0; i < _source_objs_order->length(); i++) { 409 int src_obj_index = _source_objs_order->at(i)._index; 410 oop src_obj = _source_objs->at(src_obj_index); 411 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj); 412 assert(info != nullptr, "must be"); 413 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj); 414 info->set_buffer_offset(buffer_offset); 415 assert(buffer_offset <= 0x7fffffff, "sanity"); 416 417 OopHandle handle(Universe::vm_global(), src_obj); 418 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, handle); 419 _buffer_offset_to_source_obj_table->maybe_grow(); 420 421 if (java_lang_Module::is_instance(src_obj)) { 422 Modules::check_archived_module_oop(src_obj); 423 } 424 } 425 426 log_info(aot)("Size of heap region = %zu bytes, %d objects, %d roots, %d native ptrs", 427 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs); 428 log_info(aot)(" strings = %8zu (%zu bytes)", _num_strings, _string_bytes); 429 log_info(aot)(" packages = %8zu", _num_packages); 430 log_info(aot)(" protection domains = %8zu", _num_protection_domains); 431 } 432 433 size_t AOTMappedHeapWriter::filler_array_byte_size(int length) { 434 size_t byte_size = refArrayOopDesc::object_size(length) * HeapWordSize; 435 return byte_size; 436 } 437 438 int AOTMappedHeapWriter::filler_array_length(size_t fill_bytes) { 439 assert(is_object_aligned(fill_bytes), "must be"); 440 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 441 442 int initial_length = to_array_length(fill_bytes / elemSize); 443 for (int length = initial_length; length >= 0; length --) { 444 size_t array_byte_size = filler_array_byte_size(length); 445 if (array_byte_size == fill_bytes) { 446 return length; 447 } 448 } 449 450 ShouldNotReachHere(); 451 return -1; 452 } 453 454 HeapWord* AOTMappedHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) { 455 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass 456 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used); 457 memset(mem, 0, fill_bytes); 458 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak); 459 if (UseCompactObjectHeaders) { 460 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk)); 461 } else { 462 assert(!Arguments::is_valhalla_enabled() || Universe::objectArrayKlass()->prototype_header() == markWord::prototype(), "should be the same"); 463 oopDesc::set_mark(mem, markWord::prototype()); 464 cast_to_oop(mem)->set_narrow_klass(nk); 465 } 466 arrayOopDesc::set_length(mem, array_length); 467 return mem; 468 } 469 470 void AOTMappedHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) { 471 // We fill only with arrays (so we don't need to use a single HeapWord filler if the 472 // leftover space is smaller than a zero-sized array object). Therefore, we need to 473 // make sure there's enough space of min_filler_byte_size in the current region after 474 // required_byte_size has been allocated. If not, fill the remainder of the current 475 // region. 476 size_t min_filler_byte_size = filler_array_byte_size(0); 477 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size; 478 479 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT); 480 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT); 481 482 if (cur_min_region_bottom != next_min_region_bottom) { 483 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way 484 // we can map the region in any region-based collector. 485 assert(next_min_region_bottom > cur_min_region_bottom, "must be"); 486 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT, 487 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT); 488 489 const size_t filler_end = next_min_region_bottom; 490 const size_t fill_bytes = filler_end - _buffer_used; 491 assert(fill_bytes > 0, "must be"); 492 ensure_buffer_space(filler_end); 493 494 int array_length = filler_array_length(fill_bytes); 495 log_info(aot, heap)("Inserting filler obj array of %d elements (%zu bytes total) @ buffer offset %zu", 496 array_length, fill_bytes, _buffer_used); 497 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes); 498 _buffer_used = filler_end; 499 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes); 500 } 501 } 502 503 size_t AOTMappedHeapWriter::get_filler_size_at(address buffered_addr) { 504 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr)); 505 if (p != nullptr) { 506 assert(*p > 0, "filler must be larger than zero bytes"); 507 return *p; 508 } else { 509 return 0; // buffered_addr is not a filler 510 } 511 } 512 513 template <typename T> 514 void update_buffered_object_field(address buffered_obj, int field_offset, T value) { 515 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset); 516 *field_addr = value; 517 } 518 519 void AOTMappedHeapWriter::update_stats(oop src_obj) { 520 if (java_lang_String::is_instance(src_obj)) { 521 _num_strings ++; 522 _string_bytes += src_obj->size() * HeapWordSize; 523 _string_bytes += java_lang_String::value(src_obj)->size() * HeapWordSize; 524 } else { 525 Klass* k = src_obj->klass(); 526 Symbol* name = k->name(); 527 if (name->equals("java/lang/NamedPackage") || name->equals("java/lang/Package")) { 528 _num_packages ++; 529 } else if (name->equals("java/security/ProtectionDomain")) { 530 _num_protection_domains ++; 531 } 532 } 533 } 534 535 size_t AOTMappedHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) { 536 update_stats(src_obj); 537 538 assert(!is_too_large_to_archive(src_obj), "already checked"); 539 size_t byte_size = src_obj->size() * HeapWordSize; 540 assert(byte_size > 0, "no zero-size objects"); 541 542 // For region-based collectors such as G1, the archive heap may be mapped into 543 // multiple regions. We need to make sure that we don't have an object that can possible 544 // span across two regions. 545 maybe_fill_gc_region_gap(byte_size); 546 547 size_t new_used = _buffer_used + byte_size; 548 assert(new_used > _buffer_used, "no wrap around"); 549 550 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT); 551 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT); 552 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries"); 553 554 ensure_buffer_space(new_used); 555 556 address from = cast_from_oop<address>(src_obj); 557 address to = offset_to_buffered_address<address>(_buffer_used); 558 assert(is_object_aligned(_buffer_used), "sanity"); 559 assert(is_object_aligned(byte_size), "sanity"); 560 memcpy(to, from, byte_size); 561 562 // These native pointers will be restored explicitly at run time. 563 if (java_lang_Module::is_instance(src_obj)) { 564 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr); 565 } else if (java_lang_ClassLoader::is_instance(src_obj)) { 566 #ifdef ASSERT 567 // We only archive these loaders 568 if (src_obj != SystemDictionary::java_platform_loader() && 569 src_obj != SystemDictionary::java_system_loader()) { 570 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be"); 571 } 572 #endif 573 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr); 574 } 575 576 size_t buffered_obj_offset = _buffer_used; 577 _buffer_used = new_used; 578 579 return buffered_obj_offset; 580 } 581 582 // Set the range [_requested_bottom, _requested_top), the requested address range of all 583 // the archived heap objects in the production run. 584 // 585 // (1) UseCompressedOops == true && !is_writing_deterministic_heap() 586 // 587 // The archived objects are stored using the COOPS encoding of the assembly phase. 588 // We pick a range within the heap used by the assembly phase. 589 // 590 // In the production run, if different COOPS encodings are used: 591 // - The heap contents needs to be relocated. 592 // 593 // (2) UseCompressedOops == true && is_writing_deterministic_heap() 594 // 595 // We always use zero-based, zero-shift encoding. _requested_top is aligned to 0x10000000. 596 // 597 // (3) UseCompressedOops == false: 598 // 599 // In the production run, the heap range is usually picked (randomly) by the OS, so we 600 // will almost always need to perform relocation, regardless of how we pick the requested 601 // address range. 602 // 603 // So we just hard code it to NOCOOPS_REQUESTED_BASE. 604 // 605 void AOTMappedHeapWriter::set_requested_address_range(AOTMappedHeapInfo* info) { 606 assert(!info->is_used(), "only set once"); 607 608 size_t heap_region_byte_size = _buffer_used; 609 assert(heap_region_byte_size > 0, "must archived at least one object!"); 610 611 if (UseCompressedOops) { 612 if (is_writing_deterministic_heap()) { 613 // Pick a heap range so that requested addresses can be encoded with zero-base/no shift. 614 // We align the requested bottom to at least 1 MB: if the production run uses G1 with a small 615 // heap (e.g., -Xmx256m), it's likely that we can map the archived objects at the 616 // requested location to avoid relocation. 617 // 618 // For other collectors or larger heaps, relocation is unavoidable, but is usually 619 // quite cheap. If you really want to avoid relocation, use the AOT workflow instead. 620 address heap_end = (address)0x100000000; 621 size_t alignment = MAX2(MIN_GC_REGION_ALIGNMENT, 1024 * 1024); 622 if (align_up(heap_region_byte_size, alignment) >= (size_t)heap_end) { 623 log_error(aot, heap)("cached heap space is too large: %zu bytes", heap_region_byte_size); 624 AOTMetaspace::unrecoverable_writing_error(); 625 } 626 _requested_bottom = align_down(heap_end - heap_region_byte_size, alignment); 627 } else if (UseG1GC) { 628 // For G1, pick the range at the top of the current heap. If the exact same heap sizes 629 // are used in the production run, it's likely that we can map the archived objects 630 // at the requested location to avoid relocation. 631 address heap_end = (address)G1CollectedHeap::heap()->reserved().end(); 632 log_info(aot, heap)("Heap end = %p", heap_end); 633 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes); 634 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT); 635 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity"); 636 } else { 637 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT); 638 } 639 } else { 640 // We always write the objects as if the heap started at this address. This 641 // makes the contents of the archive heap deterministic. 642 // 643 // Note that at runtime, the heap address is selected by the OS, so the archive 644 // heap will not be mapped at 0x10000000, and the contents need to be patched. 645 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT); 646 } 647 648 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity"); 649 650 _requested_top = _requested_bottom + _buffer_used; 651 652 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0), 653 offset_to_buffered_address<HeapWord*>(_buffer_used))); 654 info->set_root_segments(_heap_root_segments); 655 } 656 657 // Oop relocation 658 659 template <typename T> T* AOTMappedHeapWriter::requested_addr_to_buffered_addr(T* p) { 660 assert(is_in_requested_range(cast_to_oop(p)), "must be"); 661 662 address addr = address(p); 663 assert(addr >= _requested_bottom, "must be"); 664 size_t offset = addr - _requested_bottom; 665 return offset_to_buffered_address<T*>(offset); 666 } 667 668 template <typename T> oop AOTMappedHeapWriter::load_source_oop_from_buffer(T* buffered_addr) { 669 oop o = load_oop_from_buffer(buffered_addr); 670 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop"); 671 return o; 672 } 673 674 template <typename T> void AOTMappedHeapWriter::store_requested_oop_in_buffer(T* buffered_addr, 675 oop request_oop) { 676 assert(request_oop == nullptr || is_in_requested_range(request_oop), "must be"); 677 store_oop_in_buffer(buffered_addr, request_oop); 678 } 679 680 inline void AOTMappedHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) { 681 *buffered_addr = requested_obj; 682 } 683 684 inline void AOTMappedHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) { 685 narrowOop val = CompressedOops::encode(requested_obj); 686 *buffered_addr = val; 687 } 688 689 oop AOTMappedHeapWriter::load_oop_from_buffer(oop* buffered_addr) { 690 return *buffered_addr; 691 } 692 693 oop AOTMappedHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) { 694 return CompressedOops::decode(*buffered_addr); 695 } 696 697 template <typename T> void AOTMappedHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, oop source_referent, CHeapBitMap* oopmap) { 698 oop request_referent = source_obj_to_requested_obj(source_referent); 699 if (UseCompressedOops && is_writing_deterministic_heap()) { 700 // We use zero-based, 0-shift encoding, so the narrowOop is just the lower 701 // 32 bits of request_referent 702 intptr_t addr = cast_from_oop<intptr_t>(request_referent); 703 *((narrowOop*)field_addr_in_buffer) = CompressedOops::narrow_oop_cast(addr); 704 } else { 705 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent); 706 } 707 if (request_referent != nullptr) { 708 mark_oop_pointer<T>(field_addr_in_buffer, oopmap); 709 } 710 } 711 712 template <typename T> void AOTMappedHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) { 713 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr)); 714 address requested_region_bottom; 715 716 assert(request_p >= (T*)_requested_bottom, "sanity"); 717 assert(request_p < (T*)_requested_top, "sanity"); 718 requested_region_bottom = _requested_bottom; 719 720 // Mark the pointer in the oopmap 721 T* region_bottom = (T*)requested_region_bottom; 722 assert(request_p >= region_bottom, "must be"); 723 BitMap::idx_t idx = request_p - region_bottom; 724 assert(idx < oopmap->size(), "overflow"); 725 oopmap->set_bit(idx); 726 } 727 728 void AOTMappedHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) { 729 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass); 730 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj)); 731 732 oop fake_oop = cast_to_oop(buffered_addr); 733 if (UseCompactObjectHeaders) { 734 markWord prototype_header = src_klass->prototype_header().set_narrow_klass(nk); 735 fake_oop->set_mark(prototype_header); 736 } else { 737 fake_oop->set_narrow_klass(nk); 738 } 739 740 if (src_obj == nullptr) { 741 return; 742 } 743 // We need to retain the identity_hash, because it may have been used by some hashtables 744 // in the shared heap. 745 if (!src_obj->fast_no_hash_check() && (!(Arguments::is_valhalla_enabled() && src_obj->mark().is_inline_type()))) { 746 intptr_t src_hash = src_obj->identity_hash(); 747 if (UseCompactObjectHeaders) { 748 fake_oop->set_mark(fake_oop->mark().copy_set_hash(src_hash)); 749 } else if (Arguments::is_valhalla_enabled()) { 750 fake_oop->set_mark(src_klass->prototype_header().copy_set_hash(src_hash)); 751 } else { 752 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash)); 753 } 754 assert(fake_oop->mark().is_unlocked(), "sanity"); 755 756 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash()); 757 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash); 758 } 759 // Strip age bits. 760 fake_oop->set_mark(fake_oop->mark().set_age(0)); 761 } 762 763 class AOTMappedHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure { 764 oop _src_obj; 765 address _buffered_obj; 766 CHeapBitMap* _oopmap; 767 bool _is_java_lang_ref; 768 public: 769 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) : 770 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap) 771 { 772 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(src_obj); 773 } 774 775 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); } 776 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); } 777 778 private: 779 template <class T> void do_oop_work(T *p) { 780 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_src_obj)); 781 T* field_addr = (T*)(_buffered_obj + field_offset); 782 oop referent = load_source_oop_from_buffer<T>(field_addr); 783 referent = HeapShared::maybe_remap_referent(_is_java_lang_ref, field_offset, referent); 784 AOTMappedHeapWriter::relocate_field_in_buffer<T>(field_addr, referent, _oopmap); 785 } 786 }; 787 788 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) { 789 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end). 790 size_t start = bitmap->find_first_set_bit(0); 791 size_t end = bitmap->size(); 792 log_info(aot)("%s = %7zu ... %7zu (%3zu%% ... %3zu%% = %3zu%%)", which, 793 start, end, 794 start * 100 / total_bits, 795 end * 100 / total_bits, 796 (end - start) * 100 / total_bits); 797 } 798 799 // Update all oop fields embedded in the buffered objects 800 void AOTMappedHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots, 801 AOTMappedHeapInfo* heap_info) { 802 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)); 803 size_t heap_region_byte_size = _buffer_used; 804 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit); 805 806 for (int i = 0; i < _source_objs_order->length(); i++) { 807 int src_obj_index = _source_objs_order->at(i)._index; 808 oop src_obj = _source_objs->at(src_obj_index); 809 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj); 810 assert(info != nullptr, "must be"); 811 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset()); 812 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass()); 813 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset()); 814 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap()); 815 src_obj->oop_iterate(&relocator); 816 mark_native_pointers(src_obj); 817 }; 818 819 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and 820 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it. 821 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) { 822 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx); 823 824 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset); 825 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass()); 826 address buffered_obj = offset_to_buffered_address<address>(seg_offset); 827 int length = _heap_root_segments.size_in_elems(seg_idx); 828 829 size_t elem_size = UseCompressedOops ? sizeof(narrowOop) : sizeof(oop); 830 831 for (int i = 0; i < length; i++) { 832 // There is no source object; these are native oops - load, translate and 833 // write back 834 size_t elem_offset = objArrayOopDesc::base_offset_in_bytes() + elem_size * i; 835 HeapWord* elem_addr = (HeapWord*)(buffered_obj + elem_offset); 836 oop obj = NativeAccess<>::oop_load(elem_addr); 837 obj = HeapShared::maybe_remap_referent(false /* is_reference_field */, elem_offset, obj); 838 if (UseCompressedOops) { 839 relocate_field_in_buffer<narrowOop>((narrowOop*)elem_addr, obj, heap_info->oopmap()); 840 } else { 841 relocate_field_in_buffer<oop>((oop*)elem_addr, obj, heap_info->oopmap()); 842 } 843 } 844 } 845 846 compute_ptrmap(heap_info); 847 848 size_t total_bytes = (size_t)_buffer->length(); 849 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop))); 850 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address)); 851 } 852 853 void AOTMappedHeapWriter::mark_native_pointer(oop src_obj, int field_offset) { 854 Metadata* ptr = src_obj->metadata_field_acquire(field_offset); 855 if (ptr != nullptr) { 856 NativePointerInfo info; 857 info._src_obj = src_obj; 858 info._field_offset = field_offset; 859 _native_pointers->append(info); 860 HeapShared::set_has_native_pointers(src_obj); 861 _num_native_ptrs ++; 862 } 863 } 864 865 void AOTMappedHeapWriter::mark_native_pointers(oop orig_obj) { 866 HeapShared::do_metadata_offsets(orig_obj, [&](int offset) { 867 mark_native_pointer(orig_obj, offset); 868 }); 869 } 870 871 void AOTMappedHeapWriter::compute_ptrmap(AOTMappedHeapInfo* heap_info) { 872 int num_non_null_ptrs = 0; 873 Metadata** bottom = (Metadata**) _requested_bottom; 874 Metadata** top = (Metadata**) _requested_top; // exclusive 875 heap_info->ptrmap()->resize(top - bottom); 876 877 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small 878 for (int i = 0; i < _native_pointers->length(); i++) { 879 NativePointerInfo info = _native_pointers->at(i); 880 oop src_obj = info._src_obj; 881 int field_offset = info._field_offset; 882 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj); 883 // requested_field_addr = the address of this field in the requested space 884 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset()); 885 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset); 886 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check"); 887 888 // Mark this field in the bitmap 889 BitMap::idx_t idx = requested_field_addr - bottom; 890 heap_info->ptrmap()->set_bit(idx); 891 num_non_null_ptrs ++; 892 max_idx = MAX2(max_idx, idx); 893 894 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have 895 // this address if the RO/RW regions are mapped at the default location). 896 897 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr); 898 Metadata* native_ptr = *buffered_field_addr; 899 guarantee(native_ptr != nullptr, "sanity"); 900 901 native_ptr = RegeneratedClasses::maybe_get_regenerated_object(native_ptr); 902 903 if (!ArchiveBuilder::current()->has_been_archived((address)native_ptr)) { 904 ResourceMark rm; 905 LogStreamHandle(Error, aot) log; 906 log.print("Marking native pointer for oop %p (type = %s, offset = %d)", 907 cast_from_oop<void*>(src_obj), src_obj->klass()->external_name(), field_offset); 908 src_obj->print_on(&log); 909 fatal("Metadata %p should have been archived", native_ptr); 910 } 911 912 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr); 913 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr); 914 *buffered_field_addr = (Metadata*)requested_native_ptr; 915 } 916 917 heap_info->ptrmap()->resize(max_idx + 1); 918 log_info(aot, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (%zu bits)", 919 num_non_null_ptrs, size_t(heap_info->ptrmap()->size())); 920 } 921 922 AOTMapLogger::OopDataIterator* AOTMappedHeapWriter::oop_iterator(AOTMappedHeapInfo* heap_info) { 923 class MappedWriterOopIterator : public AOTMappedHeapOopIterator { 924 public: 925 MappedWriterOopIterator(address buffer_start, 926 address buffer_end, 927 address requested_base, 928 address requested_start, 929 int requested_shift, 930 size_t num_root_segments) : 931 AOTMappedHeapOopIterator(buffer_start, 932 buffer_end, 933 requested_base, 934 requested_start, 935 requested_shift, 936 num_root_segments) {} 937 938 AOTMapLogger::OopData capture(address buffered_addr) override { 939 oopDesc* raw_oop = (oopDesc*)buffered_addr; 940 size_t size = size_of_buffered_oop(buffered_addr); 941 address requested_addr = buffered_addr_to_requested_addr(buffered_addr); 942 intptr_t target_location = (intptr_t)requested_addr; 943 uint64_t pd = (uint64_t)(pointer_delta(buffered_addr, _buffer_start, 1)); 944 uint32_t narrow_location = checked_cast<uint32_t>(_buffer_start_narrow_oop + (pd >> _requested_shift)); 945 Klass* klass = real_klass_of_buffered_oop(buffered_addr); 946 947 return { buffered_addr, 948 requested_addr, 949 target_location, 950 narrow_location, 951 raw_oop, 952 klass, 953 size, 954 false }; 955 } 956 }; 957 958 MemRegion r = heap_info->buffer_region(); 959 address buffer_start = address(r.start()); 960 address buffer_end = address(r.end()); 961 962 address requested_base = UseCompressedOops ? AOTMappedHeapWriter::narrow_oop_base() : (address)AOTMappedHeapWriter::NOCOOPS_REQUESTED_BASE; 963 address requested_start = UseCompressedOops ? AOTMappedHeapWriter::buffered_addr_to_requested_addr(buffer_start) : requested_base; 964 int requested_shift = AOTMappedHeapWriter::narrow_oop_shift(); 965 966 return new MappedWriterOopIterator(buffer_start, 967 buffer_end, 968 requested_base, 969 requested_start, 970 requested_shift, 971 heap_info->root_segments().count()); 972 } 973 974 #endif // INCLUDE_CDS_JAVA_HEAP --- EOF ---