1 /* 2 * Copyright (c) 2014, 2023, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc/g1/g1Allocator.inline.hpp" 27 #include "gc/g1/g1CollectedHeap.inline.hpp" 28 #include "gc/g1/g1CollectionSet.hpp" 29 #include "gc/g1/g1EvacFailureRegions.inline.hpp" 30 #include "gc/g1/g1OopClosures.inline.hpp" 31 #include "gc/g1/g1ParScanThreadState.inline.hpp" 32 #include "gc/g1/g1RootClosures.hpp" 33 #include "gc/g1/g1StringDedup.hpp" 34 #include "gc/g1/g1Trace.hpp" 35 #include "gc/g1/g1YoungGCEvacFailureInjector.inline.hpp" 36 #include "gc/shared/continuationGCSupport.inline.hpp" 37 #include "gc/shared/partialArrayTaskStepper.inline.hpp" 38 #include "gc/shared/preservedMarks.inline.hpp" 39 #include "gc/shared/stringdedup/stringDedup.hpp" 40 #include "gc/shared/taskqueue.inline.hpp" 41 #include "memory/allocation.inline.hpp" 42 #include "oops/access.inline.hpp" 43 #include "oops/oop.inline.hpp" 44 #include "runtime/atomic.hpp" 45 #include "runtime/prefetch.inline.hpp" 46 #include "utilities/globalDefinitions.hpp" 47 #include "utilities/macros.hpp" 48 49 // In fastdebug builds the code size can get out of hand, potentially 50 // tripping over compiler limits (which may be bugs, but nevertheless 51 // need to be taken into consideration). A side benefit of limiting 52 // inlining is that we get more call frames that might aid debugging. 53 // And the fastdebug compile time for this file is much reduced. 54 // Explicit NOINLINE to block ATTRIBUTE_FLATTENing. 55 #define MAYBE_INLINE_EVACUATION NOT_DEBUG(inline) DEBUG_ONLY(NOINLINE) 56 57 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, 58 G1RedirtyCardsQueueSet* rdcqs, 59 PreservedMarks* preserved_marks, 60 uint worker_id, 61 uint num_workers, 62 G1CollectionSet* collection_set, 63 G1EvacFailureRegions* evac_failure_regions) 64 : _g1h(g1h), 65 _task_queue(g1h->task_queue(worker_id)), 66 _rdc_local_qset(rdcqs), 67 _ct(g1h->card_table()), 68 _closures(nullptr), 69 _plab_allocator(nullptr), 70 _age_table(false), 71 _tenuring_threshold(g1h->policy()->tenuring_threshold()), 72 _scanner(g1h, this), 73 _worker_id(worker_id), 74 _last_enqueued_card(SIZE_MAX), 75 _stack_trim_upper_threshold(GCDrainStackTargetSize * 2 + 1), 76 _stack_trim_lower_threshold(GCDrainStackTargetSize), 77 _trim_ticks(), 78 _surviving_young_words_base(nullptr), 79 _surviving_young_words(nullptr), 80 _surviving_words_length(collection_set->young_region_length() + 1), 81 _old_gen_is_full(false), 82 _partial_objarray_chunk_size(ParGCArrayScanChunk), 83 _partial_array_stepper(num_workers), 84 _string_dedup_requests(), 85 _max_num_optional_regions(collection_set->optional_region_length()), 86 _numa(g1h->numa()), 87 _obj_alloc_stat(nullptr), 88 EVAC_FAILURE_INJECTOR_ONLY(_evac_failure_inject_counter(0) COMMA) 89 _preserved_marks(preserved_marks), 90 _evacuation_failed_info(), 91 _evac_failure_regions(evac_failure_regions), 92 _evac_failure_enqueued_cards(0) 93 { 94 // We allocate number of young gen regions in the collection set plus one 95 // entries, since entry 0 keeps track of surviving bytes for non-young regions. 96 // We also add a few elements at the beginning and at the end in 97 // an attempt to eliminate cache contention 98 const size_t padding_elem_num = (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t)); 99 size_t array_length = padding_elem_num + _surviving_words_length + padding_elem_num; 100 101 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC); 102 _surviving_young_words = _surviving_young_words_base + padding_elem_num; 103 memset(_surviving_young_words, 0, _surviving_words_length * sizeof(size_t)); 104 105 _plab_allocator = new G1PLABAllocator(_g1h->allocator()); 106 107 _closures = G1EvacuationRootClosures::create_root_closures(_g1h, 108 this, 109 collection_set->only_contains_young_regions()); 110 111 _oops_into_optional_regions = new G1OopStarChunkedList[_max_num_optional_regions]; 112 113 initialize_numa_stats(); 114 } 115 116 size_t G1ParScanThreadState::flush_stats(size_t* surviving_young_words, uint num_workers) { 117 _rdc_local_qset.flush(); 118 flush_numa_stats(); 119 // Update allocation statistics. 120 _plab_allocator->flush_and_retire_stats(num_workers); 121 _g1h->policy()->record_age_table(&_age_table); 122 123 if (_evacuation_failed_info.has_failed()) { 124 _g1h->gc_tracer_stw()->report_evacuation_failed(_evacuation_failed_info); 125 } 126 127 size_t sum = 0; 128 for (uint i = 0; i < _surviving_words_length; i++) { 129 surviving_young_words[i] += _surviving_young_words[i]; 130 sum += _surviving_young_words[i]; 131 } 132 return sum; 133 } 134 135 G1ParScanThreadState::~G1ParScanThreadState() { 136 delete _plab_allocator; 137 delete _closures; 138 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); 139 delete[] _oops_into_optional_regions; 140 FREE_C_HEAP_ARRAY(size_t, _obj_alloc_stat); 141 } 142 143 size_t G1ParScanThreadState::lab_waste_words() const { 144 return _plab_allocator->waste(); 145 } 146 147 size_t G1ParScanThreadState::lab_undo_waste_words() const { 148 return _plab_allocator->undo_waste(); 149 } 150 151 size_t G1ParScanThreadState::evac_failure_enqueued_cards() const { 152 return _evac_failure_enqueued_cards; 153 } 154 155 #ifdef ASSERT 156 void G1ParScanThreadState::verify_task(narrowOop* task) const { 157 assert(task != nullptr, "invariant"); 158 assert(UseCompressedOops, "sanity"); 159 oop p = RawAccess<>::oop_load(task); 160 assert(_g1h->is_in_reserved(p), 161 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 162 } 163 164 void G1ParScanThreadState::verify_task(oop* task) const { 165 assert(task != nullptr, "invariant"); 166 oop p = RawAccess<>::oop_load(task); 167 assert(_g1h->is_in_reserved(p), 168 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 169 } 170 171 void G1ParScanThreadState::verify_task(PartialArrayScanTask task) const { 172 // Must be in the collection set--it's already been copied. 173 oop p = task.to_source_array(); 174 assert(_g1h->is_in_cset(p), "p=" PTR_FORMAT, p2i(p)); 175 } 176 177 void G1ParScanThreadState::verify_task(ScannerTask task) const { 178 if (task.is_narrow_oop_ptr()) { 179 verify_task(task.to_narrow_oop_ptr()); 180 } else if (task.is_oop_ptr()) { 181 verify_task(task.to_oop_ptr()); 182 } else if (task.is_partial_array_task()) { 183 verify_task(task.to_partial_array_task()); 184 } else { 185 ShouldNotReachHere(); 186 } 187 } 188 #endif // ASSERT 189 190 template <class T> 191 MAYBE_INLINE_EVACUATION 192 void G1ParScanThreadState::do_oop_evac(T* p) { 193 // Reference should not be null here as such are never pushed to the task queue. 194 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); 195 196 // Although we never intentionally push references outside of the collection 197 // set, due to (benign) races in the claim mechanism during RSet scanning more 198 // than one thread might claim the same card. So the same card may be 199 // processed multiple times, and so we might get references into old gen here. 200 // So we need to redo this check. 201 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj); 202 // References pushed onto the work stack should never point to a humongous region 203 // as they are not added to the collection set due to above precondition. 204 assert(!region_attr.is_humongous_candidate(), 205 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT, 206 p2i(obj), _g1h->addr_to_region(obj), p2i(p)); 207 208 if (!region_attr.is_in_cset()) { 209 // In this case somebody else already did all the work. 210 return; 211 } 212 213 markWord m = obj->mark(); 214 if (m.is_marked()) { 215 obj = cast_to_oop(m.decode_pointer()); 216 } else { 217 obj = do_copy_to_survivor_space(region_attr, obj, m); 218 } 219 RawAccess<IS_NOT_NULL>::oop_store(p, obj); 220 221 write_ref_field_post(p, obj); 222 } 223 224 MAYBE_INLINE_EVACUATION 225 void G1ParScanThreadState::do_partial_array(PartialArrayScanTask task) { 226 oop from_obj = task.to_source_array(); 227 228 assert(_g1h->is_in_reserved(from_obj), "must be in heap."); 229 assert(from_obj->is_objArray(), "must be obj array"); 230 assert(from_obj->is_forwarded(), "must be forwarded"); 231 232 oop to_obj = from_obj->forwardee(); 233 assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); 234 assert(to_obj->is_objArray(), "must be obj array"); 235 objArrayOop to_array = objArrayOop(to_obj); 236 237 PartialArrayTaskStepper::Step step 238 = _partial_array_stepper.next(objArrayOop(from_obj), 239 to_array, 240 _partial_objarray_chunk_size); 241 for (uint i = 0; i < step._ncreate; ++i) { 242 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 243 } 244 245 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array); 246 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_new_survivor()); 247 // Process claimed task. The length of to_array is not correct, but 248 // fortunately the iteration ignores the length field and just relies 249 // on start/end. 250 to_array->oop_iterate_range(&_scanner, 251 step._index, 252 step._index + _partial_objarray_chunk_size); 253 } 254 255 MAYBE_INLINE_EVACUATION 256 void G1ParScanThreadState::start_partial_objarray(G1HeapRegionAttr dest_attr, 257 oop from_obj, 258 oop to_obj) { 259 assert(from_obj->is_objArray(), "precondition"); 260 assert(from_obj->is_forwarded(), "precondition"); 261 assert(from_obj->forwardee() == to_obj, "precondition"); 262 assert(from_obj != to_obj, "should not be scanning self-forwarded objects"); 263 assert(to_obj->is_objArray(), "precondition"); 264 265 objArrayOop to_array = objArrayOop(to_obj); 266 267 PartialArrayTaskStepper::Step step 268 = _partial_array_stepper.start(objArrayOop(from_obj), 269 to_array, 270 _partial_objarray_chunk_size); 271 272 // Push any needed partial scan tasks. Pushed before processing the 273 // initial chunk to allow other workers to steal while we're processing. 274 for (uint i = 0; i < step._ncreate; ++i) { 275 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 276 } 277 278 // Skip the card enqueue iff the object (to_array) is in survivor region. 279 // However, HeapRegion::is_survivor() is too expensive here. 280 // Instead, we use dest_attr.is_young() because the two values are always 281 // equal: successfully allocated young regions must be survivor regions. 282 assert(dest_attr.is_young() == _g1h->heap_region_containing(to_array)->is_survivor(), "must be"); 283 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 284 // Process the initial chunk. No need to process the type in the 285 // klass, as it will already be handled by processing the built-in 286 // module. The length of to_array is not correct, but fortunately 287 // the iteration ignores that length field and relies on start/end. 288 to_array->oop_iterate_range(&_scanner, 0, step._index); 289 } 290 291 MAYBE_INLINE_EVACUATION 292 void G1ParScanThreadState::dispatch_task(ScannerTask task) { 293 verify_task(task); 294 if (task.is_narrow_oop_ptr()) { 295 do_oop_evac(task.to_narrow_oop_ptr()); 296 } else if (task.is_oop_ptr()) { 297 do_oop_evac(task.to_oop_ptr()); 298 } else { 299 do_partial_array(task.to_partial_array_task()); 300 } 301 } 302 303 // Process tasks until overflow queue is empty and local queue 304 // contains no more than threshold entries. NOINLINE to prevent 305 // inlining into steal_and_trim_queue. 306 ATTRIBUTE_FLATTEN NOINLINE 307 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) { 308 ScannerTask task; 309 do { 310 while (_task_queue->pop_overflow(task)) { 311 if (!_task_queue->try_push_to_taskqueue(task)) { 312 dispatch_task(task); 313 } 314 } 315 while (_task_queue->pop_local(task, threshold)) { 316 dispatch_task(task); 317 } 318 } while (!_task_queue->overflow_empty()); 319 } 320 321 ATTRIBUTE_FLATTEN 322 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) { 323 ScannerTask stolen_task; 324 while (task_queues->steal(_worker_id, stolen_task)) { 325 dispatch_task(stolen_task); 326 // Processing stolen task may have added tasks to our queue. 327 trim_queue(); 328 } 329 } 330 331 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest, 332 size_t word_sz, 333 bool previous_plab_refill_failed, 334 uint node_index) { 335 336 assert(dest->is_in_cset_or_humongous_candidate(), "Unexpected dest: %s region attr", dest->get_type_str()); 337 338 // Right now we only have two types of regions (young / old) so 339 // let's keep the logic here simple. We can generalize it when necessary. 340 if (dest->is_young()) { 341 bool plab_refill_in_old_failed = false; 342 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old, 343 word_sz, 344 &plab_refill_in_old_failed, 345 node_index); 346 // Make sure that we won't attempt to copy any other objects out 347 // of a survivor region (given that apparently we cannot allocate 348 // any new ones) to avoid coming into this slow path again and again. 349 // Only consider failed PLAB refill here: failed inline allocations are 350 // typically large, so not indicative of remaining space. 351 if (previous_plab_refill_failed) { 352 _tenuring_threshold = 0; 353 } 354 355 if (obj_ptr != nullptr) { 356 dest->set_old(); 357 } else { 358 // We just failed to allocate in old gen. The same idea as explained above 359 // for making survivor gen unavailable for allocation applies for old gen. 360 _old_gen_is_full = plab_refill_in_old_failed; 361 } 362 return obj_ptr; 363 } else { 364 _old_gen_is_full = previous_plab_refill_failed; 365 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str()); 366 // no other space to try. 367 return nullptr; 368 } 369 } 370 371 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) { 372 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old"); 373 374 if (region_attr.is_young()) { 375 age = !m.has_displaced_mark_helper() ? m.age() 376 : m.displaced_mark_helper().age(); 377 if (age < _tenuring_threshold) { 378 return region_attr; 379 } 380 } 381 // young-to-old (promotion) or old-to-old; destination is old in both cases. 382 return G1HeapRegionAttr::Old; 383 } 384 385 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr, 386 oop const old, size_t word_sz, uint age, 387 HeapWord * const obj_ptr, uint node_index) const { 388 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index); 389 if (alloc_buf->contains(obj_ptr)) { 390 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(old->klass(), word_sz * HeapWordSize, age, 391 dest_attr.type() == G1HeapRegionAttr::Old, 392 alloc_buf->word_sz() * HeapWordSize); 393 } else { 394 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(old->klass(), word_sz * HeapWordSize, age, 395 dest_attr.type() == G1HeapRegionAttr::Old); 396 } 397 } 398 399 NOINLINE 400 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr, 401 oop old, 402 size_t word_sz, 403 uint age, 404 uint node_index) { 405 HeapWord* obj_ptr = nullptr; 406 // Try slow-path allocation unless we're allocating old and old is already full. 407 if (!(dest_attr->is_old() && _old_gen_is_full)) { 408 bool plab_refill_failed = false; 409 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr, 410 word_sz, 411 &plab_refill_failed, 412 node_index); 413 if (obj_ptr == nullptr) { 414 obj_ptr = allocate_in_next_plab(dest_attr, 415 word_sz, 416 plab_refill_failed, 417 node_index); 418 } 419 } 420 if (obj_ptr != nullptr) { 421 update_numa_stats(node_index); 422 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) { 423 // The events are checked individually as part of the actual commit 424 report_promotion_event(*dest_attr, old, word_sz, age, obj_ptr, node_index); 425 } 426 } 427 return obj_ptr; 428 } 429 430 #if EVAC_FAILURE_INJECTOR 431 bool G1ParScanThreadState::inject_evacuation_failure(uint region_idx) { 432 return _g1h->evac_failure_injector()->evacuation_should_fail(_evac_failure_inject_counter, region_idx); 433 } 434 #endif 435 436 NOINLINE 437 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr, 438 HeapWord* obj_ptr, 439 size_t word_sz, 440 uint node_index) { 441 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 442 } 443 444 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) { 445 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj); 446 HeapRegion* region = _g1h->heap_region_containing(obj_start); 447 region->update_bot_for_obj(obj_start, word_sz); 448 } 449 450 // Private inline function, for direct internal use and providing the 451 // implementation of the public not-inline function. 452 MAYBE_INLINE_EVACUATION 453 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr, 454 oop const old, 455 markWord const old_mark) { 456 assert(region_attr.is_in_cset(), 457 "Unexpected region attr type: %s", region_attr.get_type_str()); 458 459 // Get the klass once. We'll need it again later, and this avoids 460 // re-decoding when it's compressed. 461 Klass* klass = old->klass(); 462 const size_t word_sz = old->size_given_klass(klass); 463 464 uint age = 0; 465 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age); 466 HeapRegion* const from_region = _g1h->heap_region_containing(old); 467 uint node_index = from_region->node_index(); 468 469 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index); 470 471 // PLAB allocations should succeed most of the time, so we'll 472 // normally check against null once and that's it. 473 if (obj_ptr == nullptr) { 474 obj_ptr = allocate_copy_slow(&dest_attr, old, word_sz, age, node_index); 475 if (obj_ptr == nullptr) { 476 // This will either forward-to-self, or detect that someone else has 477 // installed a forwarding pointer. 478 return handle_evacuation_failure_par(old, old_mark, word_sz); 479 } 480 } 481 482 assert(obj_ptr != nullptr, "when we get here, allocation should have succeeded"); 483 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap"); 484 485 // Should this evacuation fail? 486 if (inject_evacuation_failure(from_region->hrm_index())) { 487 // Doing this after all the allocation attempts also tests the 488 // undo_allocation() method too. 489 undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 490 return handle_evacuation_failure_par(old, old_mark, word_sz); 491 } 492 493 // We're going to allocate linearly, so might as well prefetch ahead. 494 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); 495 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz); 496 497 const oop obj = cast_to_oop(obj_ptr); 498 // Because the forwarding is done with memory_order_relaxed there is no 499 // ordering with the above copy. Clients that get the forwardee must not 500 // examine its contents without other synchronization, since the contents 501 // may not be up to date for them. 502 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed); 503 if (forward_ptr == nullptr) { 504 505 { 506 const uint young_index = from_region->young_index_in_cset(); 507 assert((from_region->is_young() && young_index > 0) || 508 (!from_region->is_young() && young_index == 0), "invariant" ); 509 _surviving_young_words[young_index] += word_sz; 510 } 511 512 if (dest_attr.is_young()) { 513 if (age < markWord::max_age) { 514 age++; 515 obj->incr_age(); 516 } 517 _age_table.add(age, word_sz); 518 } else { 519 update_bot_after_copying(obj, word_sz); 520 } 521 522 // Most objects are not arrays, so do one array check rather than 523 // checking for each array category for each object. 524 // CMH: Valhalla flat arrays can split this work up, but for now, doesn't 525 if (klass->is_array_klass() && !klass->is_flatArray_klass()) { 526 if (klass->is_objArray_klass()) { 527 start_partial_objarray(dest_attr, old, obj); 528 } else { 529 // Nothing needs to be done for typeArrays. Body doesn't contain 530 // any oops to scan, and the type in the klass will already be handled 531 // by processing the built-in module. 532 assert(klass->is_typeArray_klass(), "invariant"); 533 } 534 return obj; 535 } 536 537 ContinuationGCSupport::transform_stack_chunk(obj); 538 539 // Check for deduplicating young Strings. 540 if (G1StringDedup::is_candidate_from_evacuation(klass, 541 region_attr, 542 dest_attr, 543 age)) { 544 // Record old; request adds a new weak reference, which reference 545 // processing expects to refer to a from-space object. 546 _string_dedup_requests.add(old); 547 } 548 549 // Skip the card enqueue iff the object (obj) is in survivor region. 550 // However, HeapRegion::is_survivor() is too expensive here. 551 // Instead, we use dest_attr.is_young() because the two values are always 552 // equal: successfully allocated young regions must be survivor regions. 553 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be"); 554 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 555 obj->oop_iterate_backwards(&_scanner, klass); 556 return obj; 557 } else { 558 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 559 return forward_ptr; 560 } 561 } 562 563 // Public not-inline entry point. 564 ATTRIBUTE_FLATTEN 565 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr, 566 oop old, 567 markWord old_mark) { 568 return do_copy_to_survivor_space(region_attr, old, old_mark); 569 } 570 571 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) { 572 assert(worker_id < _num_workers, "out of bounds access"); 573 if (_states[worker_id] == nullptr) { 574 _states[worker_id] = 575 new G1ParScanThreadState(_g1h, rdcqs(), 576 _preserved_marks_set.get(worker_id), 577 worker_id, 578 _num_workers, 579 _collection_set, 580 _evac_failure_regions); 581 } 582 return _states[worker_id]; 583 } 584 585 const size_t* G1ParScanThreadStateSet::surviving_young_words() const { 586 assert(_flushed, "thread local state from the per thread states should have been flushed"); 587 return _surviving_young_words_total; 588 } 589 590 void G1ParScanThreadStateSet::flush_stats() { 591 assert(!_flushed, "thread local state from the per thread states should be flushed once"); 592 593 for (uint worker_id = 0; worker_id < _num_workers; ++worker_id) { 594 G1ParScanThreadState* pss = _states[worker_id]; 595 assert(pss != nullptr, "must be initialized"); 596 597 G1GCPhaseTimes* p = _g1h->phase_times(); 598 599 // Need to get the following two before the call to G1ParThreadScanState::flush() 600 // because it resets the PLAB allocator where we get this info from. 601 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize; 602 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize; 603 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _num_workers) * HeapWordSize; 604 size_t evac_fail_enqueued_cards = pss->evac_failure_enqueued_cards(); 605 606 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes); 607 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes); 608 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes); 609 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, evac_fail_enqueued_cards, G1GCPhaseTimes::MergePSSEvacFailExtra); 610 611 delete pss; 612 _states[worker_id] = nullptr; 613 } 614 _flushed = true; 615 } 616 617 void G1ParScanThreadStateSet::record_unused_optional_region(HeapRegion* hr) { 618 for (uint worker_index = 0; worker_index < _num_workers; ++worker_index) { 619 G1ParScanThreadState* pss = _states[worker_index]; 620 assert(pss != nullptr, "must be initialized"); 621 622 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory(); 623 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory); 624 } 625 } 626 627 NOINLINE 628 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, size_t word_sz) { 629 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old)); 630 631 oop forward_ptr = old->forward_to_atomic(old, m, memory_order_relaxed); 632 if (forward_ptr == nullptr) { 633 // Forward-to-self succeeded. We are the "owner" of the object. 634 HeapRegion* r = _g1h->heap_region_containing(old); 635 636 if (_evac_failure_regions->record(r->hrm_index())) { 637 _g1h->hr_printer()->evac_failure(r); 638 } 639 640 // Mark the failing object in the marking bitmap and later use the bitmap to handle 641 // evacuation failure recovery. 642 _g1h->mark_evac_failure_object(_worker_id, old, word_sz); 643 644 _preserved_marks->push_if_necessary(old, m); 645 646 ContinuationGCSupport::transform_stack_chunk(old); 647 648 _evacuation_failed_info.register_copy_failure(word_sz); 649 650 // For iterating objects that failed evacuation currently we can reuse the 651 // existing closure to scan evacuated objects; since we are iterating from a 652 // collection set region (i.e. never a Survivor region), we always need to 653 // gather cards for this case. 654 G1SkipCardEnqueueSetter x(&_scanner, false /* skip_card_enqueue */); 655 old->oop_iterate_backwards(&_scanner); 656 657 return old; 658 } else { 659 // Forward-to-self failed. Either someone else managed to allocate 660 // space for this object (old != forward_ptr) or they beat us in 661 // self-forwarding it (old == forward_ptr). 662 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr), 663 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " " 664 "should not be in the CSet", 665 p2i(old), p2i(forward_ptr)); 666 return forward_ptr; 667 } 668 } 669 670 void G1ParScanThreadState::initialize_numa_stats() { 671 if (_numa->is_enabled()) { 672 LogTarget(Info, gc, heap, numa) lt; 673 674 if (lt.is_enabled()) { 675 uint num_nodes = _numa->num_active_nodes(); 676 // Record only if there are multiple active nodes. 677 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC); 678 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes); 679 } 680 } 681 } 682 683 void G1ParScanThreadState::flush_numa_stats() { 684 if (_obj_alloc_stat != nullptr) { 685 uint node_index = _numa->index_of_current_thread(); 686 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat); 687 } 688 } 689 690 void G1ParScanThreadState::update_numa_stats(uint node_index) { 691 if (_obj_alloc_stat != nullptr) { 692 _obj_alloc_stat[node_index]++; 693 } 694 } 695 696 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h, 697 uint num_workers, 698 G1CollectionSet* collection_set, 699 G1EvacFailureRegions* evac_failure_regions) : 700 _g1h(g1h), 701 _collection_set(collection_set), 702 _rdcqs(G1BarrierSet::dirty_card_queue_set().allocator()), 703 _preserved_marks_set(true /* in_c_heap */), 704 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, num_workers, mtGC)), 705 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, collection_set->young_region_length() + 1, mtGC)), 706 _num_workers(num_workers), 707 _flushed(false), 708 _evac_failure_regions(evac_failure_regions) { 709 _preserved_marks_set.init(num_workers); 710 for (uint i = 0; i < num_workers; ++i) { 711 _states[i] = nullptr; 712 } 713 memset(_surviving_young_words_total, 0, (collection_set->young_region_length() + 1) * sizeof(size_t)); 714 } 715 716 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() { 717 assert(_flushed, "thread local state from the per thread states should have been flushed"); 718 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states); 719 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total); 720 _preserved_marks_set.reclaim(); 721 }