1 /* 2 * Copyright (c) 2014, 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 "gc/g1/g1Allocator.inline.hpp" 26 #include "gc/g1/g1CollectedHeap.inline.hpp" 27 #include "gc/g1/g1CollectionSet.hpp" 28 #include "gc/g1/g1EvacFailureRegions.inline.hpp" 29 #include "gc/g1/g1HeapRegionPrinter.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/g1YoungGCAllocationFailureInjector.inline.hpp" 36 #include "gc/shared/continuationGCSupport.inline.hpp" 37 #include "gc/shared/partialArraySplitter.inline.hpp" 38 #include "gc/shared/partialArrayState.hpp" 39 #include "gc/shared/partialArrayTaskStats.hpp" 40 #include "gc/shared/stringdedup/stringDedup.hpp" 41 #include "gc/shared/taskqueue.inline.hpp" 42 #include "memory/allocation.inline.hpp" 43 #include "oops/access.inline.hpp" 44 #include "oops/oop.inline.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/mutexLocker.hpp" 47 #include "runtime/prefetch.inline.hpp" 48 #include "utilities/globalDefinitions.hpp" 49 #include "utilities/macros.hpp" 50 51 // In fastdebug builds the code size can get out of hand, potentially 52 // tripping over compiler limits (which may be bugs, but nevertheless 53 // need to be taken into consideration). A side benefit of limiting 54 // inlining is that we get more call frames that might aid debugging. 55 // And the fastdebug compile time for this file is much reduced. 56 // Explicit NOINLINE to block ATTRIBUTE_FLATTENing. 57 #define MAYBE_INLINE_EVACUATION NOT_DEBUG(inline) DEBUG_ONLY(NOINLINE) 58 59 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, 60 G1RedirtyCardsQueueSet* rdcqs, 61 uint worker_id, 62 uint num_workers, 63 G1CollectionSet* collection_set, 64 G1EvacFailureRegions* evac_failure_regions) 65 : _g1h(g1h), 66 _task_queue(g1h->task_queue(worker_id)), 67 _rdc_local_qset(rdcqs), 68 _ct(g1h->card_table()), 69 _closures(nullptr), 70 _plab_allocator(nullptr), 71 _age_table(false), 72 _tenuring_threshold(g1h->policy()->tenuring_threshold()), 73 _scanner(g1h, this), 74 _worker_id(worker_id), 75 _last_enqueued_card(SIZE_MAX), 76 _stack_trim_upper_threshold(GCDrainStackTargetSize * 2 + 1), 77 _stack_trim_lower_threshold(GCDrainStackTargetSize), 78 _trim_ticks(), 79 _surviving_young_words_base(nullptr), 80 _surviving_young_words(nullptr), 81 _surviving_words_length(collection_set->young_region_length() + 1), 82 _old_gen_is_full(false), 83 _partial_array_splitter(g1h->partial_array_state_manager(), 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 ALLOCATION_FAILURE_INJECTOR_ONLY(_allocation_failure_inject_counter(0) COMMA) 89 _evacuation_failed_info(), 90 _evac_failure_regions(evac_failure_regions), 91 _evac_failure_enqueued_cards(0) 92 { 93 // We allocate number of young gen regions in the collection set plus one 94 // entries, since entry 0 keeps track of surviving bytes for non-young regions. 95 // We also add a few elements at the beginning and at the end in 96 // an attempt to eliminate cache contention 97 const size_t padding_elem_num = (DEFAULT_PADDING_SIZE / sizeof(size_t)); 98 size_t array_length = padding_elem_num + _surviving_words_length + padding_elem_num; 99 100 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC); 101 _surviving_young_words = _surviving_young_words_base + padding_elem_num; 102 memset(_surviving_young_words, 0, _surviving_words_length * sizeof(size_t)); 103 104 _plab_allocator = new G1PLABAllocator(_g1h->allocator()); 105 106 _closures = G1EvacuationRootClosures::create_root_closures(_g1h, 107 this, 108 collection_set->only_contains_young_regions()); 109 110 _oops_into_optional_regions = new G1OopStarChunkedList[_max_num_optional_regions]; 111 112 initialize_numa_stats(); 113 } 114 115 size_t G1ParScanThreadState::flush_stats(size_t* surviving_young_words, uint num_workers, BufferNodeList* rdc_buffers) { 116 *rdc_buffers = _rdc_local_qset.flush(); 117 flush_numa_stats(); 118 // Update allocation statistics. 119 _plab_allocator->flush_and_retire_stats(num_workers); 120 _g1h->policy()->record_age_table(&_age_table); 121 122 if (_evacuation_failed_info.has_failed()) { 123 _g1h->gc_tracer_stw()->report_evacuation_failed(_evacuation_failed_info); 124 } 125 126 size_t sum = 0; 127 for (uint i = 0; i < _surviving_words_length; i++) { 128 surviving_young_words[i] += _surviving_young_words[i]; 129 sum += _surviving_young_words[i]; 130 } 131 return sum; 132 } 133 134 G1ParScanThreadState::~G1ParScanThreadState() { 135 delete _plab_allocator; 136 delete _closures; 137 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); 138 delete[] _oops_into_optional_regions; 139 FREE_C_HEAP_ARRAY(size_t, _obj_alloc_stat); 140 } 141 142 size_t G1ParScanThreadState::lab_waste_words() const { 143 return _plab_allocator->waste(); 144 } 145 146 size_t G1ParScanThreadState::lab_undo_waste_words() const { 147 return _plab_allocator->undo_waste(); 148 } 149 150 size_t G1ParScanThreadState::evac_failure_enqueued_cards() const { 151 return _evac_failure_enqueued_cards; 152 } 153 154 #ifdef ASSERT 155 void G1ParScanThreadState::verify_task(narrowOop* task) const { 156 assert(task != nullptr, "invariant"); 157 assert(UseCompressedOops, "sanity"); 158 oop p = RawAccess<>::oop_load(task); 159 assert(_g1h->is_in_reserved(p), 160 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 161 } 162 163 void G1ParScanThreadState::verify_task(oop* task) const { 164 assert(task != nullptr, "invariant"); 165 oop p = RawAccess<>::oop_load(task); 166 assert(_g1h->is_in_reserved(p), 167 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 168 } 169 170 void G1ParScanThreadState::verify_task(PartialArrayState* task) const { 171 assert(task != nullptr, "invariant"); 172 // Source isn't used for processing, so not recorded in task. 173 assert(task->source() == nullptr, "invariant"); 174 oop p = task->destination(); 175 assert(_g1h->is_in_reserved(p), 176 "task=" PTR_FORMAT " dest=" PTR_FORMAT, p2i(task), p2i(p)); 177 } 178 179 void G1ParScanThreadState::verify_task(ScannerTask task) const { 180 if (task.is_narrow_oop_ptr()) { 181 verify_task(task.to_narrow_oop_ptr()); 182 } else if (task.is_oop_ptr()) { 183 verify_task(task.to_oop_ptr()); 184 } else if (task.is_partial_array_state()) { 185 verify_task(task.to_partial_array_state()); 186 } else { 187 ShouldNotReachHere(); 188 } 189 } 190 #endif // ASSERT 191 192 template <class T> 193 MAYBE_INLINE_EVACUATION 194 void G1ParScanThreadState::do_oop_evac(T* p) { 195 // Reference should not be null here as such are never pushed to the task queue. 196 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); 197 198 // Although we never intentionally push references outside of the collection 199 // set, due to (benign) races in the claim mechanism during RSet scanning more 200 // than one thread might claim the same card. So the same card may be 201 // processed multiple times, and so we might get references into old gen here. 202 // So we need to redo this check. 203 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj); 204 // References pushed onto the work stack should never point to a humongous region 205 // as they are not added to the collection set due to above precondition. 206 assert(!region_attr.is_humongous_candidate(), 207 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT, 208 p2i(obj), _g1h->addr_to_region(obj), p2i(p)); 209 210 if (!region_attr.is_in_cset()) { 211 // In this case somebody else already did all the work. 212 return; 213 } 214 215 markWord m = obj->mark(); 216 if (m.is_forwarded()) { 217 obj = obj->forwardee(m); 218 } else { 219 obj = do_copy_to_survivor_space(region_attr, obj, m); 220 } 221 RawAccess<IS_NOT_NULL>::oop_store(p, obj); 222 223 write_ref_field_post(p, obj); 224 } 225 226 MAYBE_INLINE_EVACUATION 227 void G1ParScanThreadState::do_partial_array(PartialArrayState* state, bool stolen) { 228 // Access state before release by claim(). 229 objArrayOop to_array = objArrayOop(state->destination()); 230 PartialArraySplitter::Claim claim = 231 _partial_array_splitter.claim(state, _task_queue, stolen); 232 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array); 233 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_new_survivor()); 234 // Process claimed task. 235 to_array->oop_iterate_range(&_scanner, 236 checked_cast<int>(claim._start), 237 checked_cast<int>(claim._end)); 238 } 239 240 MAYBE_INLINE_EVACUATION 241 void G1ParScanThreadState::start_partial_objarray(G1HeapRegionAttr dest_attr, 242 oop from_obj, 243 oop to_obj) { 244 assert(from_obj->is_forwarded(), "precondition"); 245 assert(from_obj->forwardee() == to_obj, "precondition"); 246 assert(to_obj->is_objArray(), "precondition"); 247 248 objArrayOop to_array = objArrayOop(to_obj); 249 size_t array_length = to_array->length(); 250 size_t initial_chunk_size = 251 // The source array is unused when processing states. 252 _partial_array_splitter.start(_task_queue, nullptr, to_array, array_length); 253 254 // Skip the card enqueue iff the object (to_array) is in survivor region. 255 // However, G1HeapRegion::is_survivor() is too expensive here. 256 // Instead, we use dest_attr.is_young() because the two values are always 257 // equal: successfully allocated young regions must be survivor regions. 258 assert(dest_attr.is_young() == _g1h->heap_region_containing(to_array)->is_survivor(), "must be"); 259 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 260 // Process the initial chunk. No need to process the type in the 261 // klass, as it will already be handled by processing the built-in 262 // module. 263 to_array->oop_iterate_range(&_scanner, 0, checked_cast<int>(initial_chunk_size)); 264 } 265 266 MAYBE_INLINE_EVACUATION 267 void G1ParScanThreadState::dispatch_task(ScannerTask task, bool stolen) { 268 verify_task(task); 269 if (task.is_narrow_oop_ptr()) { 270 do_oop_evac(task.to_narrow_oop_ptr()); 271 } else if (task.is_oop_ptr()) { 272 do_oop_evac(task.to_oop_ptr()); 273 } else { 274 do_partial_array(task.to_partial_array_state(), stolen); 275 } 276 } 277 278 // Process tasks until overflow queue is empty and local queue 279 // contains no more than threshold entries. NOINLINE to prevent 280 // inlining into steal_and_trim_queue. 281 ATTRIBUTE_FLATTEN NOINLINE 282 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) { 283 ScannerTask task; 284 do { 285 while (_task_queue->pop_overflow(task)) { 286 if (!_task_queue->try_push_to_taskqueue(task)) { 287 dispatch_task(task, false); 288 } 289 } 290 while (_task_queue->pop_local(task, threshold)) { 291 dispatch_task(task, false); 292 } 293 } while (!_task_queue->overflow_empty()); 294 } 295 296 ATTRIBUTE_FLATTEN 297 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) { 298 ScannerTask stolen_task; 299 while (task_queues->steal(_worker_id, stolen_task)) { 300 dispatch_task(stolen_task, true); 301 // Processing stolen task may have added tasks to our queue. 302 trim_queue(); 303 } 304 } 305 306 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest, 307 size_t word_sz, 308 bool previous_plab_refill_failed, 309 uint node_index) { 310 311 assert(dest->is_in_cset_or_humongous_candidate(), "Unexpected dest: %s region attr", dest->get_type_str()); 312 313 // Right now we only have two types of regions (young / old) so 314 // let's keep the logic here simple. We can generalize it when necessary. 315 if (dest->is_young()) { 316 bool plab_refill_in_old_failed = false; 317 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old, 318 word_sz, 319 &plab_refill_in_old_failed, 320 node_index); 321 // Make sure that we won't attempt to copy any other objects out 322 // of a survivor region (given that apparently we cannot allocate 323 // any new ones) to avoid coming into this slow path again and again. 324 // Only consider failed PLAB refill here: failed inline allocations are 325 // typically large, so not indicative of remaining space. 326 if (previous_plab_refill_failed) { 327 _tenuring_threshold = 0; 328 } 329 330 if (obj_ptr != nullptr) { 331 dest->set_old(); 332 } else { 333 // We just failed to allocate in old gen. The same idea as explained above 334 // for making survivor gen unavailable for allocation applies for old gen. 335 _old_gen_is_full = plab_refill_in_old_failed; 336 } 337 return obj_ptr; 338 } else { 339 _old_gen_is_full = previous_plab_refill_failed; 340 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str()); 341 // no other space to try. 342 return nullptr; 343 } 344 } 345 346 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) { 347 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old"); 348 349 if (region_attr.is_young()) { 350 age = !m.has_displaced_mark_helper() ? m.age() 351 : m.displaced_mark_helper().age(); 352 if (age < _tenuring_threshold) { 353 return region_attr; 354 } 355 } 356 // young-to-old (promotion) or old-to-old; destination is old in both cases. 357 return G1HeapRegionAttr::Old; 358 } 359 360 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr, 361 Klass* klass, size_t word_sz, uint age, 362 HeapWord * const obj_ptr, uint node_index) const { 363 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index); 364 if (alloc_buf->contains(obj_ptr)) { 365 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(klass, word_sz * HeapWordSize, age, 366 dest_attr.type() == G1HeapRegionAttr::Old, 367 alloc_buf->word_sz() * HeapWordSize); 368 } else { 369 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(klass, word_sz * HeapWordSize, age, 370 dest_attr.type() == G1HeapRegionAttr::Old); 371 } 372 } 373 374 NOINLINE 375 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr, 376 Klass* klass, 377 size_t word_sz, 378 uint age, 379 uint node_index) { 380 HeapWord* obj_ptr = nullptr; 381 // Try slow-path allocation unless we're allocating old and old is already full. 382 if (!(dest_attr->is_old() && _old_gen_is_full)) { 383 bool plab_refill_failed = false; 384 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr, 385 word_sz, 386 &plab_refill_failed, 387 node_index); 388 if (obj_ptr == nullptr) { 389 obj_ptr = allocate_in_next_plab(dest_attr, 390 word_sz, 391 plab_refill_failed, 392 node_index); 393 } 394 } 395 if (obj_ptr != nullptr) { 396 update_numa_stats(node_index); 397 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) { 398 // The events are checked individually as part of the actual commit 399 report_promotion_event(*dest_attr, klass, word_sz, age, obj_ptr, node_index); 400 } 401 } 402 return obj_ptr; 403 } 404 405 #if ALLOCATION_FAILURE_INJECTOR 406 bool G1ParScanThreadState::inject_allocation_failure(uint region_idx) { 407 return _g1h->allocation_failure_injector()->allocation_should_fail(_allocation_failure_inject_counter, region_idx); 408 } 409 #endif 410 411 NOINLINE 412 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr, 413 HeapWord* obj_ptr, 414 size_t word_sz, 415 uint node_index) { 416 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 417 } 418 419 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) { 420 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj); 421 G1HeapRegion* region = _g1h->heap_region_containing(obj_start); 422 region->update_bot_for_block(obj_start, obj_start + word_sz); 423 } 424 425 // Private inline function, for direct internal use and providing the 426 // implementation of the public not-inline function. 427 MAYBE_INLINE_EVACUATION 428 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr, 429 oop const old, 430 markWord const old_mark) { 431 assert(region_attr.is_in_cset(), 432 "Unexpected region attr type: %s", region_attr.get_type_str()); 433 434 // NOTE: With compact headers, it is not safe to load the Klass* from old, because 435 // that would access the mark-word, that might change at any time by concurrent 436 // workers. 437 // This mark word would refer to a forwardee, which may not yet have completed 438 // copying. Therefore we must load the Klass* from the mark-word that we already 439 // loaded. This is safe, because we only enter here if not yet forwarded. 440 assert(!old_mark.is_forwarded(), "precondition"); 441 Klass* klass = UseCompactObjectHeaders 442 ? old_mark.klass() 443 : old->klass(); 444 445 const size_t word_sz = old->size_given_klass(klass); 446 447 // JNI only allows pinning of typeArrays, so we only need to keep those in place. 448 if (region_attr.is_pinned() && klass->is_typeArray_klass()) { 449 return handle_evacuation_failure_par(old, old_mark, word_sz, true /* cause_pinned */); 450 } 451 452 uint age = 0; 453 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age); 454 G1HeapRegion* const from_region = _g1h->heap_region_containing(old); 455 uint node_index = from_region->node_index(); 456 457 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index); 458 459 // PLAB allocations should succeed most of the time, so we'll 460 // normally check against null once and that's it. 461 if (obj_ptr == nullptr) { 462 obj_ptr = allocate_copy_slow(&dest_attr, klass, word_sz, age, node_index); 463 if (obj_ptr == nullptr) { 464 // This will either forward-to-self, or detect that someone else has 465 // installed a forwarding pointer. 466 return handle_evacuation_failure_par(old, old_mark, word_sz, false /* cause_pinned */); 467 } 468 } 469 470 assert(obj_ptr != nullptr, "when we get here, allocation should have succeeded"); 471 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap"); 472 473 // Should this evacuation fail? 474 if (inject_allocation_failure(from_region->hrm_index())) { 475 // Doing this after all the allocation attempts also tests the 476 // undo_allocation() method too. 477 undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 478 return handle_evacuation_failure_par(old, old_mark, word_sz, false /* cause_pinned */); 479 } 480 481 // We're going to allocate linearly, so might as well prefetch ahead. 482 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); 483 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz); 484 485 const oop obj = cast_to_oop(obj_ptr); 486 // Because the forwarding is done with memory_order_relaxed there is no 487 // ordering with the above copy. Clients that get the forwardee must not 488 // examine its contents without other synchronization, since the contents 489 // may not be up to date for them. 490 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed); 491 if (forward_ptr == nullptr) { 492 493 { 494 const uint young_index = from_region->young_index_in_cset(); 495 assert((from_region->is_young() && young_index > 0) || 496 (!from_region->is_young() && young_index == 0), "invariant" ); 497 _surviving_young_words[young_index] += word_sz; 498 } 499 500 if (dest_attr.is_young()) { 501 if (age < markWord::max_age) { 502 age++; 503 obj->incr_age(); 504 } 505 _age_table.add(age, word_sz); 506 } else { 507 update_bot_after_copying(obj, word_sz); 508 } 509 510 // Most objects are not arrays, so do one array check rather than 511 // checking for each array category for each object. 512 if (klass->is_array_klass()) { 513 if (klass->is_objArray_klass()) { 514 start_partial_objarray(dest_attr, old, obj); 515 } else { 516 // Nothing needs to be done for typeArrays. Body doesn't contain 517 // any oops to scan, and the type in the klass will already be handled 518 // by processing the built-in module. 519 assert(klass->is_typeArray_klass(), "invariant"); 520 } 521 return obj; 522 } 523 524 ContinuationGCSupport::transform_stack_chunk(obj); 525 526 // Check for deduplicating young Strings. 527 if (G1StringDedup::is_candidate_from_evacuation(klass, 528 region_attr, 529 dest_attr, 530 age)) { 531 // Record old; request adds a new weak reference, which reference 532 // processing expects to refer to a from-space object. 533 _string_dedup_requests.add(old); 534 } 535 536 // Skip the card enqueue iff the object (obj) is in survivor region. 537 // However, G1HeapRegion::is_survivor() is too expensive here. 538 // Instead, we use dest_attr.is_young() because the two values are always 539 // equal: successfully allocated young regions must be survivor regions. 540 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be"); 541 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 542 obj->oop_iterate_backwards(&_scanner, klass); 543 return obj; 544 } else { 545 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 546 return forward_ptr; 547 } 548 } 549 550 // Public not-inline entry point. 551 ATTRIBUTE_FLATTEN 552 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr, 553 oop old, 554 markWord old_mark) { 555 return do_copy_to_survivor_space(region_attr, old, old_mark); 556 } 557 558 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) { 559 assert(worker_id < _num_workers, "out of bounds access"); 560 if (_states[worker_id] == nullptr) { 561 _states[worker_id] = 562 new G1ParScanThreadState(_g1h, rdcqs(), 563 worker_id, 564 _num_workers, 565 _collection_set, 566 _evac_failure_regions); 567 } 568 return _states[worker_id]; 569 } 570 571 const size_t* G1ParScanThreadStateSet::surviving_young_words() const { 572 assert(_flushed, "thread local state from the per thread states should have been flushed"); 573 return _surviving_young_words_total; 574 } 575 576 void G1ParScanThreadStateSet::flush_stats() { 577 assert(!_flushed, "thread local state from the per thread states should be flushed once"); 578 for (uint worker_id = 0; worker_id < _num_workers; ++worker_id) { 579 G1ParScanThreadState* pss = _states[worker_id]; 580 assert(pss != nullptr, "must be initialized"); 581 582 G1GCPhaseTimes* p = _g1h->phase_times(); 583 584 // Need to get the following two before the call to G1ParThreadScanState::flush() 585 // because it resets the PLAB allocator where we get this info from. 586 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize; 587 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize; 588 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _num_workers, &_rdc_buffers[worker_id]) * HeapWordSize; 589 size_t evac_fail_enqueued_cards = pss->evac_failure_enqueued_cards(); 590 591 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes); 592 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes); 593 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes); 594 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, evac_fail_enqueued_cards, G1GCPhaseTimes::MergePSSEvacFailExtra); 595 596 delete pss; 597 _states[worker_id] = nullptr; 598 } 599 600 G1DirtyCardQueueSet& dcq = G1BarrierSet::dirty_card_queue_set(); 601 dcq.merge_bufferlists(rdcqs()); 602 rdcqs()->verify_empty(); 603 604 _flushed = true; 605 } 606 607 void G1ParScanThreadStateSet::record_unused_optional_region(G1HeapRegion* hr) { 608 for (uint worker_index = 0; worker_index < _num_workers; ++worker_index) { 609 G1ParScanThreadState* pss = _states[worker_index]; 610 assert(pss != nullptr, "must be initialized"); 611 612 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory(); 613 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory); 614 } 615 } 616 617 NOINLINE 618 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, size_t word_sz, bool cause_pinned) { 619 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old)); 620 621 oop forward_ptr = old->forward_to_self_atomic(m, memory_order_relaxed); 622 if (forward_ptr == nullptr) { 623 // Forward-to-self succeeded. We are the "owner" of the object. 624 G1HeapRegion* r = _g1h->heap_region_containing(old); 625 626 if (_evac_failure_regions->record(_worker_id, r->hrm_index(), cause_pinned)) { 627 G1HeapRegionPrinter::evac_failure(r); 628 } 629 630 // Mark the failing object in the marking bitmap and later use the bitmap to handle 631 // evacuation failure recovery. 632 _g1h->mark_evac_failure_object(_worker_id, old, word_sz); 633 634 ContinuationGCSupport::transform_stack_chunk(old); 635 636 _evacuation_failed_info.register_copy_failure(word_sz); 637 638 // For iterating objects that failed evacuation currently we can reuse the 639 // existing closure to scan evacuated objects; since we are iterating from a 640 // collection set region (i.e. never a Survivor region), we always need to 641 // gather cards for this case. 642 G1SkipCardEnqueueSetter x(&_scanner, false /* skip_card_enqueue */); 643 old->oop_iterate_backwards(&_scanner); 644 645 return old; 646 } else { 647 // Forward-to-self failed. Either someone else managed to allocate 648 // space for this object (old != forward_ptr) or they beat us in 649 // self-forwarding it (old == forward_ptr). 650 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr), 651 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " " 652 "should not be in the CSet", 653 p2i(old), p2i(forward_ptr)); 654 return forward_ptr; 655 } 656 } 657 658 void G1ParScanThreadState::initialize_numa_stats() { 659 if (_numa->is_enabled()) { 660 LogTarget(Info, gc, heap, numa) lt; 661 662 if (lt.is_enabled()) { 663 uint num_nodes = _numa->num_active_nodes(); 664 // Record only if there are multiple active nodes. 665 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC); 666 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes); 667 } 668 } 669 } 670 671 void G1ParScanThreadState::flush_numa_stats() { 672 if (_obj_alloc_stat != nullptr) { 673 uint node_index = _numa->index_of_current_thread(); 674 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat); 675 } 676 } 677 678 void G1ParScanThreadState::update_numa_stats(uint node_index) { 679 if (_obj_alloc_stat != nullptr) { 680 _obj_alloc_stat[node_index]++; 681 } 682 } 683 684 #if TASKQUEUE_STATS 685 686 PartialArrayTaskStats* G1ParScanThreadState::partial_array_task_stats() { 687 return _partial_array_splitter.stats(); 688 } 689 690 #endif // TASKQUEUE_STATS 691 692 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h, 693 uint num_workers, 694 G1CollectionSet* collection_set, 695 G1EvacFailureRegions* evac_failure_regions) : 696 _g1h(g1h), 697 _collection_set(collection_set), 698 _rdcqs(G1BarrierSet::dirty_card_queue_set().allocator()), 699 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, num_workers, mtGC)), 700 _rdc_buffers(NEW_C_HEAP_ARRAY(BufferNodeList, num_workers, mtGC)), 701 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, collection_set->young_region_length() + 1, mtGC)), 702 _num_workers(num_workers), 703 _flushed(false), 704 _evac_failure_regions(evac_failure_regions) 705 { 706 for (uint i = 0; i < num_workers; ++i) { 707 _states[i] = nullptr; 708 _rdc_buffers[i] = BufferNodeList(); 709 } 710 memset(_surviving_young_words_total, 0, (collection_set->young_region_length() + 1) * sizeof(size_t)); 711 } 712 713 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() { 714 assert(_flushed, "thread local state from the per thread states should have been flushed"); 715 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states); 716 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total); 717 FREE_C_HEAP_ARRAY(BufferNodeList, _rdc_buffers); 718 } 719 720 #if TASKQUEUE_STATS 721 722 void G1ParScanThreadStateSet::print_partial_array_task_stats() { 723 auto get_stats = [&](uint i) { 724 return state_for_worker(i)->partial_array_task_stats(); 725 }; 726 PartialArrayTaskStats::log_set(_num_workers, get_stats, 727 "Partial Array Task Stats"); 728 } 729 730 #endif // TASKQUEUE_STATS