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/partialArrayTaskStepper.inline.hpp" 37 #include "gc/shared/preservedMarks.inline.hpp" 38 #include "gc/shared/stringdedup/stringDedup.hpp" 39 #include "gc/shared/taskqueue.inline.hpp" 40 #include "memory/allocation.inline.hpp" 41 #include "oops/access.inline.hpp" 42 #include "oops/oop.inline.hpp" 43 #include "runtime/atomic.hpp" 44 #include "runtime/prefetch.inline.hpp" 45 #include "utilities/globalDefinitions.hpp" 46 #include "utilities/macros.hpp" 47 48 // In fastdebug builds the code size can get out of hand, potentially 49 // tripping over compiler limits (which may be bugs, but nevertheless 50 // need to be taken into consideration). A side benefit of limiting 51 // inlining is that we get more call frames that might aid debugging. 52 // And the fastdebug compile time for this file is much reduced. 53 // Explicit NOINLINE to block ATTRIBUTE_FLATTENing. 54 #define MAYBE_INLINE_EVACUATION NOT_DEBUG(inline) DEBUG_ONLY(NOINLINE) 55 56 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, 57 G1RedirtyCardsQueueSet* rdcqs, 58 PreservedMarks* preserved_marks, 59 uint worker_id, 60 uint n_workers, 61 size_t young_cset_length, 62 size_t optional_cset_length, 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(NULL), 69 _plab_allocator(NULL), 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(NULL), 79 _surviving_young_words(NULL), 80 _surviving_words_length(young_cset_length + 1), 81 _old_gen_is_full(false), 82 _partial_objarray_chunk_size(ParGCArrayScanChunk), 83 _partial_array_stepper(n_workers), 84 _string_dedup_requests(), 85 _num_optional_regions(optional_cset_length), 86 _numa(g1h->numa()), 87 _obj_alloc_stat(NULL), 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 { 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_CACHE_LINE_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(this, _g1h); 107 108 _oops_into_optional_regions = new G1OopStarChunkedList[_num_optional_regions]; 109 110 initialize_numa_stats(); 111 } 112 113 size_t G1ParScanThreadState::flush(size_t* surviving_young_words) { 114 _rdc_local_qset.flush(); 115 flush_numa_stats(); 116 // Update allocation statistics. 117 _plab_allocator->flush_and_retire_stats(); 118 _g1h->policy()->record_age_table(&_age_table); 119 120 if (_evacuation_failed_info.has_failed()) { 121 _g1h->gc_tracer_stw()->report_evacuation_failed(_evacuation_failed_info); 122 } 123 124 size_t sum = 0; 125 for (uint i = 0; i < _surviving_words_length; i++) { 126 surviving_young_words[i] += _surviving_young_words[i]; 127 sum += _surviving_young_words[i]; 128 } 129 return sum; 130 } 131 132 G1ParScanThreadState::~G1ParScanThreadState() { 133 delete _plab_allocator; 134 delete _closures; 135 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); 136 delete[] _oops_into_optional_regions; 137 FREE_C_HEAP_ARRAY(size_t, _obj_alloc_stat); 138 } 139 140 size_t G1ParScanThreadState::lab_waste_words() const { 141 return _plab_allocator->waste(); 142 } 143 144 size_t G1ParScanThreadState::lab_undo_waste_words() const { 145 return _plab_allocator->undo_waste(); 146 } 147 148 #ifdef ASSERT 149 void G1ParScanThreadState::verify_task(narrowOop* task) const { 150 assert(task != NULL, "invariant"); 151 assert(UseCompressedOops, "sanity"); 152 oop p = RawAccess<>::oop_load(task); 153 assert(_g1h->is_in_reserved(p), 154 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p)); 155 } 156 157 void G1ParScanThreadState::verify_task(oop* task) const { 158 assert(task != NULL, "invariant"); 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(PartialArrayScanTask task) const { 165 // Must be in the collection set--it's already been copied. 166 oop p = task.to_source_array(); 167 assert(_g1h->is_in_cset(p), "p=" PTR_FORMAT, p2i(p)); 168 } 169 170 void G1ParScanThreadState::verify_task(ScannerTask task) const { 171 if (task.is_narrow_oop_ptr()) { 172 verify_task(task.to_narrow_oop_ptr()); 173 } else if (task.is_oop_ptr()) { 174 verify_task(task.to_oop_ptr()); 175 } else if (task.is_partial_array_task()) { 176 verify_task(task.to_partial_array_task()); 177 } else { 178 ShouldNotReachHere(); 179 } 180 } 181 #endif // ASSERT 182 183 template <class T> 184 MAYBE_INLINE_EVACUATION 185 void G1ParScanThreadState::do_oop_evac(T* p) { 186 // Reference should not be NULL here as such are never pushed to the task queue. 187 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); 188 189 // Although we never intentionally push references outside of the collection 190 // set, due to (benign) races in the claim mechanism during RSet scanning more 191 // than one thread might claim the same card. So the same card may be 192 // processed multiple times, and so we might get references into old gen here. 193 // So we need to redo this check. 194 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj); 195 // References pushed onto the work stack should never point to a humongous region 196 // as they are not added to the collection set due to above precondition. 197 assert(!region_attr.is_humongous(), 198 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT, 199 p2i(obj), _g1h->addr_to_region(cast_from_oop<HeapWord*>(obj)), p2i(p)); 200 201 if (!region_attr.is_in_cset()) { 202 // In this case somebody else already did all the work. 203 return; 204 } 205 206 markWord m = obj->mark(); 207 if (m.is_marked()) { 208 obj = obj->forwardee(m); 209 } else { 210 obj = do_copy_to_survivor_space(region_attr, obj, m); 211 } 212 RawAccess<IS_NOT_NULL>::oop_store(p, obj); 213 214 write_ref_field_post(p, obj); 215 } 216 217 MAYBE_INLINE_EVACUATION 218 void G1ParScanThreadState::do_partial_array(PartialArrayScanTask task) { 219 oop from_obj = task.to_source_array(); 220 221 assert(_g1h->is_in_reserved(from_obj), "must be in heap."); 222 assert(from_obj->is_forwarded(), "must be forwarded"); 223 224 oop to_obj = from_obj->forwardee(); 225 assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); 226 assert(to_obj->is_objArray(), "must be obj array"); 227 objArrayOop to_array = objArrayOop(to_obj); 228 229 PartialArrayTaskStepper::Step step 230 = _partial_array_stepper.next(objArrayOop(from_obj), 231 to_array, 232 _partial_objarray_chunk_size); 233 for (uint i = 0; i < step._ncreate; ++i) { 234 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 235 } 236 237 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array); 238 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_new_survivor()); 239 // Process claimed task. The length of to_array is not correct, but 240 // fortunately the iteration ignores the length field and just relies 241 // on start/end. 242 to_array->oop_iterate_range(&_scanner, 243 step._index, 244 step._index + _partial_objarray_chunk_size); 245 } 246 247 MAYBE_INLINE_EVACUATION 248 void G1ParScanThreadState::start_partial_objarray(G1HeapRegionAttr dest_attr, 249 oop from_obj, 250 oop to_obj) { 251 assert(from_obj->is_forwarded(), "precondition"); 252 assert(from_obj->forwardee() == to_obj, "precondition"); 253 assert(from_obj != to_obj, "should not be scanning self-forwarded objects"); 254 assert(to_obj->is_objArray(), "precondition"); 255 256 objArrayOop to_array = objArrayOop(to_obj); 257 258 PartialArrayTaskStepper::Step step 259 = _partial_array_stepper.start(objArrayOop(from_obj), 260 to_array, 261 _partial_objarray_chunk_size); 262 263 // Push any needed partial scan tasks. Pushed before processing the 264 // initial chunk to allow other workers to steal while we're processing. 265 for (uint i = 0; i < step._ncreate; ++i) { 266 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj))); 267 } 268 269 // Skip the card enqueue iff the object (to_array) is in survivor region. 270 // However, HeapRegion::is_survivor() is too expensive here. 271 // Instead, we use dest_attr.is_young() because the two values are always 272 // equal: successfully allocated young regions must be survivor regions. 273 assert(dest_attr.is_young() == _g1h->heap_region_containing(to_array)->is_survivor(), "must be"); 274 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 275 // Process the initial chunk. No need to process the type in the 276 // klass, as it will already be handled by processing the built-in 277 // module. The length of to_array is not correct, but fortunately 278 // the iteration ignores that length field and relies on start/end. 279 to_array->oop_iterate_range(&_scanner, 0, step._index); 280 } 281 282 MAYBE_INLINE_EVACUATION 283 void G1ParScanThreadState::dispatch_task(ScannerTask task) { 284 verify_task(task); 285 if (task.is_narrow_oop_ptr()) { 286 do_oop_evac(task.to_narrow_oop_ptr()); 287 } else if (task.is_oop_ptr()) { 288 do_oop_evac(task.to_oop_ptr()); 289 } else { 290 do_partial_array(task.to_partial_array_task()); 291 } 292 } 293 294 // Process tasks until overflow queue is empty and local queue 295 // contains no more than threshold entries. NOINLINE to prevent 296 // inlining into steal_and_trim_queue. 297 ATTRIBUTE_FLATTEN NOINLINE 298 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) { 299 ScannerTask task; 300 do { 301 while (_task_queue->pop_overflow(task)) { 302 if (!_task_queue->try_push_to_taskqueue(task)) { 303 dispatch_task(task); 304 } 305 } 306 while (_task_queue->pop_local(task, threshold)) { 307 dispatch_task(task); 308 } 309 } while (!_task_queue->overflow_empty()); 310 } 311 312 ATTRIBUTE_FLATTEN 313 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) { 314 ScannerTask stolen_task; 315 while (task_queues->steal(_worker_id, stolen_task)) { 316 dispatch_task(stolen_task); 317 // Processing stolen task may have added tasks to our queue. 318 trim_queue(); 319 } 320 } 321 322 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest, 323 size_t word_sz, 324 bool previous_plab_refill_failed, 325 uint node_index) { 326 327 assert(dest->is_in_cset_or_humongous(), "Unexpected dest: %s region attr", dest->get_type_str()); 328 329 // Right now we only have two types of regions (young / old) so 330 // let's keep the logic here simple. We can generalize it when necessary. 331 if (dest->is_young()) { 332 bool plab_refill_in_old_failed = false; 333 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old, 334 word_sz, 335 &plab_refill_in_old_failed, 336 node_index); 337 // Make sure that we won't attempt to copy any other objects out 338 // of a survivor region (given that apparently we cannot allocate 339 // any new ones) to avoid coming into this slow path again and again. 340 // Only consider failed PLAB refill here: failed inline allocations are 341 // typically large, so not indicative of remaining space. 342 if (previous_plab_refill_failed) { 343 _tenuring_threshold = 0; 344 } 345 346 if (obj_ptr != NULL) { 347 dest->set_old(); 348 } else { 349 // We just failed to allocate in old gen. The same idea as explained above 350 // for making survivor gen unavailable for allocation applies for old gen. 351 _old_gen_is_full = plab_refill_in_old_failed; 352 } 353 return obj_ptr; 354 } else { 355 _old_gen_is_full = previous_plab_refill_failed; 356 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str()); 357 // no other space to try. 358 return NULL; 359 } 360 } 361 362 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) { 363 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old"); 364 365 if (region_attr.is_young()) { 366 age = !m.has_displaced_mark_helper() ? m.age() 367 : m.displaced_mark_helper().age(); 368 if (age < _tenuring_threshold) { 369 return region_attr; 370 } 371 } 372 // young-to-old (promotion) or old-to-old; destination is old in both cases. 373 return G1HeapRegionAttr::Old; 374 } 375 376 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr, 377 oop const old, Klass* klass, size_t word_sz, uint age, 378 HeapWord * const obj_ptr, uint node_index) const { 379 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index); 380 if (alloc_buf->contains(obj_ptr)) { 381 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(klass, word_sz * HeapWordSize, age, 382 dest_attr.type() == G1HeapRegionAttr::Old, 383 alloc_buf->word_sz() * HeapWordSize); 384 } else { 385 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(klass, word_sz * HeapWordSize, age, 386 dest_attr.type() == G1HeapRegionAttr::Old); 387 } 388 } 389 390 NOINLINE 391 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr, 392 oop old, 393 Klass* klass, 394 size_t word_sz, 395 uint age, 396 uint node_index) { 397 HeapWord* obj_ptr = NULL; 398 // Try slow-path allocation unless we're allocating old and old is already full. 399 if (!(dest_attr->is_old() && _old_gen_is_full)) { 400 bool plab_refill_failed = false; 401 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr, 402 word_sz, 403 &plab_refill_failed, 404 node_index); 405 if (obj_ptr == NULL) { 406 obj_ptr = allocate_in_next_plab(dest_attr, 407 word_sz, 408 plab_refill_failed, 409 node_index); 410 } 411 } 412 if (obj_ptr != NULL) { 413 update_numa_stats(node_index); 414 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) { 415 // The events are checked individually as part of the actual commit 416 report_promotion_event(*dest_attr, old, klass, word_sz, age, obj_ptr, node_index); 417 } 418 } 419 return obj_ptr; 420 } 421 422 #if EVAC_FAILURE_INJECTOR 423 bool G1ParScanThreadState::inject_evacuation_failure(uint region_idx) { 424 return _g1h->evac_failure_injector()->evacuation_should_fail(_evac_failure_inject_counter, region_idx); 425 } 426 #endif 427 428 NOINLINE 429 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr, 430 HeapWord* obj_ptr, 431 size_t word_sz, 432 uint node_index) { 433 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 434 } 435 436 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) { 437 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj); 438 HeapRegion* region = _g1h->heap_region_containing(obj_start); 439 region->update_bot_for_obj(obj_start, word_sz); 440 } 441 442 // Private inline function, for direct internal use and providing the 443 // implementation of the public not-inline function. 444 MAYBE_INLINE_EVACUATION 445 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr, 446 oop const old, 447 markWord const old_mark) { 448 assert(region_attr.is_in_cset(), 449 "Unexpected region attr type: %s", region_attr.get_type_str()); 450 451 if (old_mark.is_marked()) { 452 // Already forwarded by somebody else, return forwardee. 453 return old->forwardee(old_mark); 454 } 455 // Get the klass once. We'll need it again later, and this avoids 456 // re-decoding when it's compressed. 457 #ifdef _LP64 458 Klass* klass = old_mark.safe_klass(); 459 #else 460 Klass* klass = old->klass(); 461 #endif 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 == NULL) { 474 obj_ptr = allocate_copy_slow(&dest_attr, old, klass, word_sz, age, node_index); 475 if (obj_ptr == NULL) { 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 != NULL, "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 == NULL) { 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 if (klass->is_array_klass()) { 525 if (klass->is_objArray_klass()) { 526 start_partial_objarray(dest_attr, old, obj); 527 } else { 528 // Nothing needs to be done for typeArrays. Body doesn't contain 529 // any oops to scan, and the type in the klass will already be handled 530 // by processing the built-in module. 531 assert(klass->is_typeArray_klass(), "invariant"); 532 } 533 return obj; 534 } 535 536 // Check for deduplicating young Strings. 537 if (G1StringDedup::is_candidate_from_evacuation(klass, 538 region_attr, 539 dest_attr, 540 age)) { 541 // Record old; request adds a new weak reference, which reference 542 // processing expects to refer to a from-space object. 543 _string_dedup_requests.add(old); 544 } 545 546 // Skip the card enqueue iff the object (obj) is in survivor region. 547 // However, HeapRegion::is_survivor() is too expensive here. 548 // Instead, we use dest_attr.is_young() because the two values are always 549 // equal: successfully allocated young regions must be survivor regions. 550 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be"); 551 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young()); 552 obj->oop_iterate_backwards(&_scanner, klass); 553 return obj; 554 } else { 555 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index); 556 return forward_ptr; 557 } 558 } 559 560 // Public not-inline entry point. 561 ATTRIBUTE_FLATTEN 562 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr, 563 oop old, 564 markWord old_mark) { 565 return do_copy_to_survivor_space(region_attr, old, old_mark); 566 } 567 568 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) { 569 assert(worker_id < _n_workers, "out of bounds access"); 570 if (_states[worker_id] == NULL) { 571 _states[worker_id] = 572 new G1ParScanThreadState(_g1h, rdcqs(), 573 _preserved_marks_set->get(worker_id), 574 worker_id, _n_workers, 575 _young_cset_length, _optional_cset_length, 576 _evac_failure_regions); 577 } 578 return _states[worker_id]; 579 } 580 581 const size_t* G1ParScanThreadStateSet::surviving_young_words() const { 582 assert(_flushed, "thread local state from the per thread states should have been flushed"); 583 return _surviving_young_words_total; 584 } 585 586 void G1ParScanThreadStateSet::flush() { 587 assert(!_flushed, "thread local state from the per thread states should be flushed once"); 588 589 for (uint worker_id = 0; worker_id < _n_workers; ++worker_id) { 590 G1ParScanThreadState* pss = _states[worker_id]; 591 assert(pss != nullptr, "must be initialized"); 592 593 G1GCPhaseTimes* p = _g1h->phase_times(); 594 595 // Need to get the following two before the call to G1ParThreadScanState::flush() 596 // because it resets the PLAB allocator where we get this info from. 597 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize; 598 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize; 599 size_t copied_bytes = pss->flush(_surviving_young_words_total) * HeapWordSize; 600 601 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes); 602 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes); 603 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes); 604 605 delete pss; 606 _states[worker_id] = NULL; 607 } 608 _flushed = true; 609 } 610 611 void G1ParScanThreadStateSet::record_unused_optional_region(HeapRegion* hr) { 612 for (uint worker_index = 0; worker_index < _n_workers; ++worker_index) { 613 G1ParScanThreadState* pss = _states[worker_index]; 614 assert(pss != nullptr, "must be initialized"); 615 616 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory(); 617 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory); 618 } 619 } 620 621 NOINLINE 622 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, size_t word_sz) { 623 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old)); 624 625 oop forward_ptr = old->forward_to_self_atomic(m, memory_order_relaxed); 626 if (forward_ptr == NULL) { 627 // Forward-to-self succeeded. We are the "owner" of the object. 628 HeapRegion* r = _g1h->heap_region_containing(old); 629 630 // Objects failing evacuation will turn into old objects since the regions 631 // are relabeled as such. We mark the failing objects in the prev bitmap and 632 // later use it to handle all failed objects. 633 _g1h->mark_evac_failure_object(old, _worker_id); 634 635 if (_evac_failure_regions->record(r->hrm_index())) { 636 _g1h->hr_printer()->evac_failure(r); 637 } 638 639 _preserved_marks->push_if_necessary(old, m); 640 _evacuation_failed_info.register_copy_failure(word_sz); 641 642 // For iterating objects that failed evacuation currently we can reuse the 643 // existing closure to scan evacuated objects because: 644 // - for objects referring into the collection set we do not need to gather 645 // cards at this time. The regions they are in will be unconditionally turned 646 // to old regions without remembered sets. 647 // - since we are iterating from a collection set region (i.e. never a Survivor 648 // region), we always need to gather cards for this case. 649 G1SkipCardEnqueueSetter x(&_scanner, false /* skip_card_enqueue */); 650 old->oop_iterate_backwards(&_scanner); 651 652 return old; 653 } else { 654 // Forward-to-self failed. Either someone else managed to allocate 655 // space for this object (old != forward_ptr) or they beat us in 656 // self-forwarding it (old == forward_ptr). 657 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr), 658 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " " 659 "should not be in the CSet", 660 p2i(old), p2i(forward_ptr)); 661 return forward_ptr; 662 } 663 } 664 665 void G1ParScanThreadState::initialize_numa_stats() { 666 if (_numa->is_enabled()) { 667 LogTarget(Info, gc, heap, numa) lt; 668 669 if (lt.is_enabled()) { 670 uint num_nodes = _numa->num_active_nodes(); 671 // Record only if there are multiple active nodes. 672 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC); 673 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes); 674 } 675 } 676 } 677 678 void G1ParScanThreadState::flush_numa_stats() { 679 if (_obj_alloc_stat != NULL) { 680 uint node_index = _numa->index_of_current_thread(); 681 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat); 682 } 683 } 684 685 void G1ParScanThreadState::update_numa_stats(uint node_index) { 686 if (_obj_alloc_stat != NULL) { 687 _obj_alloc_stat[node_index]++; 688 } 689 } 690 691 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h, 692 G1RedirtyCardsQueueSet* rdcqs, 693 PreservedMarksSet* preserved_marks_set, 694 uint n_workers, 695 size_t young_cset_length, 696 size_t optional_cset_length, 697 G1EvacFailureRegions* evac_failure_regions) : 698 _g1h(g1h), 699 _rdcqs(rdcqs), 700 _preserved_marks_set(preserved_marks_set), 701 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, n_workers, mtGC)), 702 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, young_cset_length + 1, mtGC)), 703 _young_cset_length(young_cset_length), 704 _optional_cset_length(optional_cset_length), 705 _n_workers(n_workers), 706 _flushed(false), 707 _evac_failure_regions(evac_failure_regions) { 708 for (uint i = 0; i < n_workers; ++i) { 709 _states[i] = NULL; 710 } 711 memset(_surviving_young_words_total, 0, (young_cset_length + 1) * sizeof(size_t)); 712 } 713 714 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() { 715 assert(_flushed, "thread local state from the per thread states should have been flushed"); 716 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states); 717 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total); 718 }