1 /* 2 * Copyright (c) 2014, 2022, 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 n_workers, 62 size_t young_cset_length, 63 size_t optional_cset_length, 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(NULL), 70 _plab_allocator(NULL), 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(NULL), 80 _surviving_young_words(NULL), 81 _surviving_words_length(young_cset_length + 1), 82 _old_gen_is_full(false), 83 _partial_objarray_chunk_size(ParGCArrayScanChunk), 84 _partial_array_stepper(n_workers), 85 _string_dedup_requests(), 86 _num_optional_regions(optional_cset_length), 87 _numa(g1h->numa()), 88 _obj_alloc_stat(NULL), 89 EVAC_FAILURE_INJECTOR_ONLY(_evac_failure_inject_counter(0) COMMA) 90 _preserved_marks(preserved_marks), 91 _evacuation_failed_info(), 92 _evac_failure_regions(evac_failure_regions) 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(this, _g1h); 108 109 _oops_into_optional_regions = new G1OopStarChunkedList[_num_optional_regions]; 110 111 initialize_numa_stats(); 112 } 113 114 size_t G1ParScanThreadState::flush_stats(size_t* surviving_young_words, uint num_workers) { 115 _rdc_local_qset.flush(); 116 flush_numa_stats(); 117 // Update allocation statistics. 118 _plab_allocator->flush_and_retire_stats(num_workers); 119 _g1h->policy()->record_age_table(&_age_table); 120 121 if (_evacuation_failed_info.has_failed()) { 122 _g1h->gc_tracer_stw()->report_evacuation_failed(_evacuation_failed_info); 123 } 124 125 size_t sum = 0; 126 for (uint i = 0; i < _surviving_words_length; i++) { 127 surviving_young_words[i] += _surviving_young_words[i]; 128 sum += _surviving_young_words[i]; 129 } 130 return sum; 131 } 132 133 G1ParScanThreadState::~G1ParScanThreadState() { 134 delete _plab_allocator; 135 delete _closures; 136 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); 137 delete[] _oops_into_optional_regions; 138 FREE_C_HEAP_ARRAY(size_t, _obj_alloc_stat); 139 } 140 141 size_t G1ParScanThreadState::lab_waste_words() const { 142 return _plab_allocator->waste(); 143 } 144 145 size_t G1ParScanThreadState::lab_undo_waste_words() const { 146 return _plab_allocator->undo_waste(); 147 } 148 149 #ifdef ASSERT 150 void G1ParScanThreadState::verify_task(narrowOop* task) const { 151 assert(task != NULL, "invariant"); 152 assert(UseCompressedOops, "sanity"); 153 oop p = RawAccess<>::oop_load(task); 154 assert(_g1h->is_in_reserved(p), 155 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 156 } 157 158 void G1ParScanThreadState::verify_task(oop* task) const { 159 assert(task != NULL, "invariant"); 160 oop p = RawAccess<>::oop_load(task); 161 assert(_g1h->is_in_reserved(p), 162 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 163 } 164 165 void G1ParScanThreadState::verify_task(PartialArrayScanTask task) const { 166 // Must be in the collection set--it's already been copied. 167 oop p = task.to_source_array(); 168 assert(_g1h->is_in_cset(p), "p=" PTR_FORMAT, p2i(p)); 169 } 170 171 void G1ParScanThreadState::verify_task(ScannerTask task) const { 172 if (task.is_narrow_oop_ptr()) { 173 verify_task(task.to_narrow_oop_ptr()); 174 } else if (task.is_oop_ptr()) { 175 verify_task(task.to_oop_ptr()); 176 } else if (task.is_partial_array_task()) { 177 verify_task(task.to_partial_array_task()); 178 } else { 179 ShouldNotReachHere(); 180 } 181 } 182 #endif // ASSERT 183 184 template <class T> 185 MAYBE_INLINE_EVACUATION 186 void G1ParScanThreadState::do_oop_evac(T* p) { 187 // Reference should not be NULL here as such are never pushed to the task queue. 188 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); 189 190 // Although we never intentionally push references outside of the collection 191 // set, due to (benign) races in the claim mechanism during RSet scanning more 192 // than one thread might claim the same card. So the same card may be 193 // processed multiple times, and so we might get references into old gen here. 194 // So we need to redo this check. 195 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj); 196 // References pushed onto the work stack should never point to a humongous region 197 // as they are not added to the collection set due to above precondition. 198 assert(!region_attr.is_humongous_candidate(), 199 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT, 200 p2i(obj), _g1h->addr_to_region(obj), p2i(p)); 201 202 if (!region_attr.is_in_cset()) { 203 // In this case somebody else already did all the work. 204 return; 205 } 206 207 markWord m = obj->mark(); 208 if (m.is_marked()) { 209 obj = cast_to_oop(m.decode_pointer()); 210 } else { 211 obj = do_copy_to_survivor_space(region_attr, obj, m); 212 } 213 RawAccess<IS_NOT_NULL>::oop_store(p, obj); 214 215 write_ref_field_post(p, obj); 216 } 217 218 MAYBE_INLINE_EVACUATION 219 void G1ParScanThreadState::do_partial_array(PartialArrayScanTask task) { 220 oop from_obj = task.to_source_array(); 221 222 assert(_g1h->is_in_reserved(from_obj), "must be in heap."); 223 assert(from_obj->is_objArray(), "must be obj array"); 224 assert(from_obj->is_forwarded(), "must be forwarded"); 225 226 oop to_obj = from_obj->forwardee(); 227 assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); 228 assert(to_obj->is_objArray(), "must be obj array"); 229 objArrayOop to_array = objArrayOop(to_obj); 230 231 PartialArrayTaskStepper::Step step 232 = _partial_array_stepper.next(objArrayOop(from_obj), 233 to_array, 234 _partial_objarray_chunk_size); 235 for (uint i = 0; i < step._ncreate; ++i) { 236 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 237 } 238 239 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array); 240 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_new_survivor()); 241 // Process claimed task. The length of to_array is not correct, but 242 // fortunately the iteration ignores the length field and just relies 243 // on start/end. 244 to_array->oop_iterate_range(&_scanner, 245 step._index, 246 step._index + _partial_objarray_chunk_size); 247 } 248 249 MAYBE_INLINE_EVACUATION 250 void G1ParScanThreadState::start_partial_objarray(G1HeapRegionAttr dest_attr, 251 oop from_obj, 252 oop to_obj) { 253 assert(from_obj->is_objArray(), "precondition"); 254 assert(from_obj->is_forwarded(), "precondition"); 255 assert(from_obj->forwardee() == to_obj, "precondition"); 256 assert(from_obj != to_obj, "should not be scanning self-forwarded objects"); 257 assert(to_obj->is_objArray(), "precondition"); 258 259 objArrayOop to_array = objArrayOop(to_obj); 260 261 PartialArrayTaskStepper::Step step 262 = _partial_array_stepper.start(objArrayOop(from_obj), 263 to_array, 264 _partial_objarray_chunk_size); 265 266 // Push any needed partial scan tasks. Pushed before processing the 267 // initial chunk to allow other workers to steal while we're processing. 268 for (uint i = 0; i < step._ncreate; ++i) { 269 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 270 } 271 272 // Skip the card enqueue iff the object (to_array) is in survivor region. 273 // However, HeapRegion::is_survivor() is too expensive here. 274 // Instead, we use dest_attr.is_young() because the two values are always 275 // equal: successfully allocated young regions must be survivor regions. 276 assert(dest_attr.is_young() == _g1h->heap_region_containing(to_array)->is_survivor(), "must be"); 277 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 278 // Process the initial chunk. No need to process the type in the 279 // klass, as it will already be handled by processing the built-in 280 // module. The length of to_array is not correct, but fortunately 281 // the iteration ignores that length field and relies on start/end. 282 to_array->oop_iterate_range(&_scanner, 0, step._index); 283 } 284 285 MAYBE_INLINE_EVACUATION 286 void G1ParScanThreadState::dispatch_task(ScannerTask task) { 287 verify_task(task); 288 if (task.is_narrow_oop_ptr()) { 289 do_oop_evac(task.to_narrow_oop_ptr()); 290 } else if (task.is_oop_ptr()) { 291 do_oop_evac(task.to_oop_ptr()); 292 } else { 293 do_partial_array(task.to_partial_array_task()); 294 } 295 } 296 297 // Process tasks until overflow queue is empty and local queue 298 // contains no more than threshold entries. NOINLINE to prevent 299 // inlining into steal_and_trim_queue. 300 ATTRIBUTE_FLATTEN NOINLINE 301 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) { 302 ScannerTask task; 303 do { 304 while (_task_queue->pop_overflow(task)) { 305 if (!_task_queue->try_push_to_taskqueue(task)) { 306 dispatch_task(task); 307 } 308 } 309 while (_task_queue->pop_local(task, threshold)) { 310 dispatch_task(task); 311 } 312 } while (!_task_queue->overflow_empty()); 313 } 314 315 ATTRIBUTE_FLATTEN 316 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) { 317 ScannerTask stolen_task; 318 while (task_queues->steal(_worker_id, stolen_task)) { 319 dispatch_task(stolen_task); 320 // Processing stolen task may have added tasks to our queue. 321 trim_queue(); 322 } 323 } 324 325 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest, 326 size_t word_sz, 327 bool previous_plab_refill_failed, 328 uint node_index) { 329 330 assert(dest->is_in_cset_or_humongous_candidate(), "Unexpected dest: %s region attr", dest->get_type_str()); 331 332 // Right now we only have two types of regions (young / old) so 333 // let's keep the logic here simple. We can generalize it when necessary. 334 if (dest->is_young()) { 335 bool plab_refill_in_old_failed = false; 336 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old, 337 word_sz, 338 &plab_refill_in_old_failed, 339 node_index); 340 // Make sure that we won't attempt to copy any other objects out 341 // of a survivor region (given that apparently we cannot allocate 342 // any new ones) to avoid coming into this slow path again and again. 343 // Only consider failed PLAB refill here: failed inline allocations are 344 // typically large, so not indicative of remaining space. 345 if (previous_plab_refill_failed) { 346 _tenuring_threshold = 0; 347 } 348 349 if (obj_ptr != NULL) { 350 dest->set_old(); 351 } else { 352 // We just failed to allocate in old gen. The same idea as explained above 353 // for making survivor gen unavailable for allocation applies for old gen. 354 _old_gen_is_full = plab_refill_in_old_failed; 355 } 356 return obj_ptr; 357 } else { 358 _old_gen_is_full = previous_plab_refill_failed; 359 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str()); 360 // no other space to try. 361 return NULL; 362 } 363 } 364 365 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) { 366 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old"); 367 368 if (region_attr.is_young()) { 369 age = !m.has_displaced_mark_helper() ? m.age() 370 : m.displaced_mark_helper().age(); 371 if (age < _tenuring_threshold) { 372 return region_attr; 373 } 374 } 375 // young-to-old (promotion) or old-to-old; destination is old in both cases. 376 return G1HeapRegionAttr::Old; 377 } 378 379 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr, 380 oop const old, size_t word_sz, uint age, 381 HeapWord * const obj_ptr, uint node_index) const { 382 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index); 383 if (alloc_buf->contains(obj_ptr)) { 384 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(old->klass(), word_sz * HeapWordSize, age, 385 dest_attr.type() == G1HeapRegionAttr::Old, 386 alloc_buf->word_sz() * HeapWordSize); 387 } else { 388 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(old->klass(), word_sz * HeapWordSize, age, 389 dest_attr.type() == G1HeapRegionAttr::Old); 390 } 391 } 392 393 NOINLINE 394 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr, 395 oop old, 396 size_t word_sz, 397 uint age, 398 uint node_index) { 399 HeapWord* obj_ptr = NULL; 400 // Try slow-path allocation unless we're allocating old and old is already full. 401 if (!(dest_attr->is_old() && _old_gen_is_full)) { 402 bool plab_refill_failed = false; 403 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr, 404 word_sz, 405 &plab_refill_failed, 406 node_index); 407 if (obj_ptr == NULL) { 408 obj_ptr = allocate_in_next_plab(dest_attr, 409 word_sz, 410 plab_refill_failed, 411 node_index); 412 } 413 } 414 if (obj_ptr != NULL) { 415 update_numa_stats(node_index); 416 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) { 417 // The events are checked individually as part of the actual commit 418 report_promotion_event(*dest_attr, old, word_sz, age, obj_ptr, node_index); 419 } 420 } 421 return obj_ptr; 422 } 423 424 #if EVAC_FAILURE_INJECTOR 425 bool G1ParScanThreadState::inject_evacuation_failure(uint region_idx) { 426 return _g1h->evac_failure_injector()->evacuation_should_fail(_evac_failure_inject_counter, region_idx); 427 } 428 #endif 429 430 NOINLINE 431 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr, 432 HeapWord* obj_ptr, 433 size_t word_sz, 434 uint node_index) { 435 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 436 } 437 438 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) { 439 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj); 440 HeapRegion* region = _g1h->heap_region_containing(obj_start); 441 region->update_bot_for_obj(obj_start, word_sz); 442 } 443 444 // Private inline function, for direct internal use and providing the 445 // implementation of the public not-inline function. 446 MAYBE_INLINE_EVACUATION 447 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr, 448 oop const old, 449 markWord const old_mark) { 450 assert(region_attr.is_in_cset(), 451 "Unexpected region attr type: %s", region_attr.get_type_str()); 452 453 // Get the klass once. We'll need it again later, and this avoids 454 // re-decoding when it's compressed. 455 Klass* klass = old->klass(); 456 const size_t word_sz = old->size_given_klass(klass); 457 458 uint age = 0; 459 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age); 460 HeapRegion* const from_region = _g1h->heap_region_containing(old); 461 uint node_index = from_region->node_index(); 462 463 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index); 464 465 // PLAB allocations should succeed most of the time, so we'll 466 // normally check against NULL once and that's it. 467 if (obj_ptr == NULL) { 468 obj_ptr = allocate_copy_slow(&dest_attr, old, word_sz, age, node_index); 469 if (obj_ptr == NULL) { 470 // This will either forward-to-self, or detect that someone else has 471 // installed a forwarding pointer. 472 return handle_evacuation_failure_par(old, old_mark, word_sz); 473 } 474 } 475 476 assert(obj_ptr != NULL, "when we get here, allocation should have succeeded"); 477 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap"); 478 479 // Should this evacuation fail? 480 if (inject_evacuation_failure(from_region->hrm_index())) { 481 // Doing this after all the allocation attempts also tests the 482 // undo_allocation() method too. 483 undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 484 return handle_evacuation_failure_par(old, old_mark, word_sz); 485 } 486 487 // We're going to allocate linearly, so might as well prefetch ahead. 488 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); 489 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz); 490 491 const oop obj = cast_to_oop(obj_ptr); 492 // Because the forwarding is done with memory_order_relaxed there is no 493 // ordering with the above copy. Clients that get the forwardee must not 494 // examine its contents without other synchronization, since the contents 495 // may not be up to date for them. 496 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed); 497 if (forward_ptr == NULL) { 498 499 { 500 const uint young_index = from_region->young_index_in_cset(); 501 assert((from_region->is_young() && young_index > 0) || 502 (!from_region->is_young() && young_index == 0), "invariant" ); 503 _surviving_young_words[young_index] += word_sz; 504 } 505 506 if (dest_attr.is_young()) { 507 if (age < markWord::max_age) { 508 age++; 509 obj->incr_age(); 510 } 511 _age_table.add(age, word_sz); 512 } else { 513 update_bot_after_copying(obj, word_sz); 514 } 515 516 // Most objects are not arrays, so do one array check rather than 517 // checking for each array category for each object. 518 if (klass->is_array_klass()) { 519 if (klass->is_objArray_klass()) { 520 start_partial_objarray(dest_attr, old, obj); 521 } else { 522 // Nothing needs to be done for typeArrays. Body doesn't contain 523 // any oops to scan, and the type in the klass will already be handled 524 // by processing the built-in module. 525 assert(klass->is_typeArray_klass(), "invariant"); 526 } 527 return obj; 528 } 529 530 ContinuationGCSupport::transform_stack_chunk(obj); 531 532 // Check for deduplicating young Strings. 533 if (G1StringDedup::is_candidate_from_evacuation(klass, 534 region_attr, 535 dest_attr, 536 age)) { 537 // Record old; request adds a new weak reference, which reference 538 // processing expects to refer to a from-space object. 539 _string_dedup_requests.add(old); 540 } 541 542 // Skip the card enqueue iff the object (obj) is in survivor region. 543 // However, HeapRegion::is_survivor() is too expensive here. 544 // Instead, we use dest_attr.is_young() because the two values are always 545 // equal: successfully allocated young regions must be survivor regions. 546 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be"); 547 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 548 obj->oop_iterate_backwards(&_scanner, klass); 549 return obj; 550 } else { 551 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 552 return forward_ptr; 553 } 554 } 555 556 // Public not-inline entry point. 557 ATTRIBUTE_FLATTEN 558 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr, 559 oop old, 560 markWord old_mark) { 561 return do_copy_to_survivor_space(region_attr, old, old_mark); 562 } 563 564 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) { 565 assert(worker_id < _n_workers, "out of bounds access"); 566 if (_states[worker_id] == NULL) { 567 _states[worker_id] = 568 new G1ParScanThreadState(_g1h, rdcqs(), 569 _preserved_marks_set.get(worker_id), 570 worker_id, _n_workers, 571 _young_cset_length, _optional_cset_length, 572 _evac_failure_regions); 573 } 574 return _states[worker_id]; 575 } 576 577 const size_t* G1ParScanThreadStateSet::surviving_young_words() const { 578 assert(_flushed, "thread local state from the per thread states should have been flushed"); 579 return _surviving_young_words_total; 580 } 581 582 void G1ParScanThreadStateSet::flush_stats() { 583 assert(!_flushed, "thread local state from the per thread states should be flushed once"); 584 585 for (uint worker_id = 0; worker_id < _n_workers; ++worker_id) { 586 G1ParScanThreadState* pss = _states[worker_id]; 587 assert(pss != nullptr, "must be initialized"); 588 589 G1GCPhaseTimes* p = _g1h->phase_times(); 590 591 // Need to get the following two before the call to G1ParThreadScanState::flush() 592 // because it resets the PLAB allocator where we get this info from. 593 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize; 594 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize; 595 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _n_workers) * HeapWordSize; 596 597 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes); 598 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes); 599 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes); 600 601 delete pss; 602 _states[worker_id] = NULL; 603 } 604 _flushed = true; 605 } 606 607 void G1ParScanThreadStateSet::record_unused_optional_region(HeapRegion* hr) { 608 for (uint worker_index = 0; worker_index < _n_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) { 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_atomic(old, m, memory_order_relaxed); 622 if (forward_ptr == NULL) { 623 // Forward-to-self succeeded. We are the "owner" of the object. 624 HeapRegion* r = _g1h->heap_region_containing(old); 625 626 if (_evac_failure_regions->record(r->hrm_index())) { 627 _g1h->hr_printer()->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 _preserved_marks->push_if_necessary(old, m); 635 636 ContinuationGCSupport::transform_stack_chunk(old); 637 638 _evacuation_failed_info.register_copy_failure(word_sz); 639 640 // For iterating objects that failed evacuation currently we can reuse the 641 // existing closure to scan evacuated objects because: 642 // - for objects referring into the collection set we do not need to gather 643 // cards at this time. The regions they are in will be unconditionally turned 644 // to old regions without remembered sets. 645 // - since we are iterating from a collection set region (i.e. never a Survivor 646 // region), we always need to gather cards for this case. 647 G1SkipCardEnqueueSetter x(&_scanner, false /* skip_card_enqueue */); 648 old->oop_iterate_backwards(&_scanner); 649 650 return old; 651 } else { 652 // Forward-to-self failed. Either someone else managed to allocate 653 // space for this object (old != forward_ptr) or they beat us in 654 // self-forwarding it (old == forward_ptr). 655 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr), 656 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " " 657 "should not be in the CSet", 658 p2i(old), p2i(forward_ptr)); 659 return forward_ptr; 660 } 661 } 662 663 void G1ParScanThreadState::initialize_numa_stats() { 664 if (_numa->is_enabled()) { 665 LogTarget(Info, gc, heap, numa) lt; 666 667 if (lt.is_enabled()) { 668 uint num_nodes = _numa->num_active_nodes(); 669 // Record only if there are multiple active nodes. 670 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC); 671 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes); 672 } 673 } 674 } 675 676 void G1ParScanThreadState::flush_numa_stats() { 677 if (_obj_alloc_stat != NULL) { 678 uint node_index = _numa->index_of_current_thread(); 679 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat); 680 } 681 } 682 683 void G1ParScanThreadState::update_numa_stats(uint node_index) { 684 if (_obj_alloc_stat != NULL) { 685 _obj_alloc_stat[node_index]++; 686 } 687 } 688 689 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h, 690 uint n_workers, 691 size_t young_cset_length, 692 size_t optional_cset_length, 693 G1EvacFailureRegions* evac_failure_regions) : 694 _g1h(g1h), 695 _rdcqs(G1BarrierSet::dirty_card_queue_set().allocator()), 696 _preserved_marks_set(true /* in_c_heap */), 697 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, n_workers, mtGC)), 698 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, young_cset_length + 1, mtGC)), 699 _young_cset_length(young_cset_length), 700 _optional_cset_length(optional_cset_length), 701 _n_workers(n_workers), 702 _flushed(false), 703 _evac_failure_regions(evac_failure_regions) { 704 _preserved_marks_set.init(n_workers); 705 for (uint i = 0; i < n_workers; ++i) { 706 _states[i] = NULL; 707 } 708 memset(_surviving_young_words_total, 0, (young_cset_length + 1) * sizeof(size_t)); 709 } 710 711 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() { 712 assert(_flushed, "thread local state from the per thread states should have been flushed"); 713 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states); 714 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total); 715 _preserved_marks_set.assert_empty(); 716 _preserved_marks_set.reclaim(); 717 }