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.
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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/atomicAccess.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 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 _ct(g1h->refinement_table()),
67 _closures(nullptr),
68 _plab_allocator(nullptr),
69 _age_table(false),
70 _tenuring_threshold(g1h->policy()->tenuring_threshold()),
71 _scanner(g1h, this),
72 _worker_id(worker_id),
73 _num_cards_marked_dirty(0),
74 _num_cards_marked_to_cset(0),
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_array_splitter(g1h->partial_array_state_manager(), num_workers, ParGCArrayScanChunk),
83 _string_dedup_requests(),
84 _max_num_optional_regions(collection_set->num_optional_regions()),
85 _numa(g1h->numa()),
86 _obj_alloc_stat(nullptr),
87 ALLOCATION_FAILURE_INJECTOR_ONLY(_allocation_failure_inject_counter(0) COMMA)
88 _evacuation_failed_info(),
89 _evac_failure_regions(evac_failure_regions),
90 _num_cards_from_evac_failure(0)
91 {
92 // We allocate number of young gen regions in the collection set plus one
93 // entries, since entry 0 keeps track of surviving bytes for non-young regions.
94 // We also add a few elements at the beginning and at the end in
95 // an attempt to eliminate cache contention
96 const size_t padding_elem_num = (DEFAULT_PADDING_SIZE / sizeof(size_t));
97 size_t array_length = padding_elem_num + _surviving_words_length + padding_elem_num;
98
99 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
100 _surviving_young_words = _surviving_young_words_base + padding_elem_num;
101 memset(_surviving_young_words, 0, _surviving_words_length * sizeof(size_t));
102
103 _plab_allocator = new G1PLABAllocator(_g1h->allocator());
104
105 _closures = G1EvacuationRootClosures::create_root_closures(_g1h,
106 this,
107 collection_set->only_contains_young_regions());
108
109 _oops_into_optional_regions = new G1OopStarChunkedList[_max_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 flush_numa_stats();
116 // Update allocation statistics.
117 _plab_allocator->flush_and_retire_stats(num_workers);
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 size_t G1ParScanThreadState::num_cards_pending() const {
149 return _num_cards_marked_dirty + _num_cards_from_evac_failure;
150 }
151
152 size_t G1ParScanThreadState::num_cards_marked() const {
153 return num_cards_pending() + _num_cards_marked_to_cset;
154 }
155
156 size_t G1ParScanThreadState::num_cards_from_evac_failure() const {
157 return _num_cards_from_evac_failure;
158 }
159
160 #ifdef ASSERT
161 void G1ParScanThreadState::verify_task(narrowOop* task) const {
162 assert(task != nullptr, "invariant");
163 assert(UseCompressedOops, "sanity");
164 oop p = RawAccess<>::oop_load(task);
165 assert(_g1h->is_in_reserved(p),
166 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p));
167 }
168
169 void G1ParScanThreadState::verify_task(oop* task) const {
170 assert(task != nullptr, "invariant");
171 oop p = RawAccess<>::oop_load(task);
172 assert(_g1h->is_in_reserved(p),
173 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p));
174 }
175
176 void G1ParScanThreadState::verify_task(PartialArrayState* task) const {
177 assert(task != nullptr, "invariant");
178 // Source isn't used for processing, so not recorded in task.
179 assert(task->source() == nullptr, "invariant");
180 oop p = task->destination();
181 assert(_g1h->is_in_reserved(p),
182 "task=" PTR_FORMAT " dest=" PTR_FORMAT, p2i(task), p2i(p));
183 }
184
185 void G1ParScanThreadState::verify_task(ScannerTask task) const {
186 if (task.is_narrow_oop_ptr()) {
187 verify_task(task.to_narrow_oop_ptr());
188 } else if (task.is_oop_ptr()) {
189 verify_task(task.to_oop_ptr());
190 } else if (task.is_partial_array_state()) {
191 verify_task(task.to_partial_array_state());
192 } else {
193 ShouldNotReachHere();
194 }
195 }
196 #endif // ASSERT
197
198 template <class T>
199 MAYBE_INLINE_EVACUATION
200 void G1ParScanThreadState::do_oop_evac(T* p) {
201 // Reference should not be null here as such are never pushed to the task queue.
202 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
203
204 // Although we never intentionally push references outside of the collection
205 // set, due to (benign) races in the claim mechanism during RSet scanning more
206 // than one thread might claim the same card. So the same card may be
207 // processed multiple times, and so we might get references into old gen here.
208 // So we need to redo this check.
209 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
210 // References pushed onto the work stack should never point to a humongous region
211 // as they are not added to the collection set due to above precondition.
212 assert(!region_attr.is_humongous_candidate(),
213 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT,
214 p2i(obj), _g1h->addr_to_region(obj), p2i(p));
215
216 if (!region_attr.is_in_cset()) {
217 // In this case somebody else already did all the work.
218 return;
219 }
220
221 markWord m = obj->mark();
222 if (m.is_forwarded()) {
223 obj = obj->forwardee(m);
224 } else {
225 obj = do_copy_to_survivor_space(region_attr, obj, m);
226 }
227 RawAccess<IS_NOT_NULL>::oop_store(p, obj);
228
229 write_ref_field_post(p, obj);
230 }
231
232 MAYBE_INLINE_EVACUATION
233 void G1ParScanThreadState::do_partial_array(PartialArrayState* state, bool stolen) {
234 // Access state before release by claim().
235 objArrayOop to_array = objArrayOop(state->destination());
236 PartialArraySplitter::Claim claim =
237 _partial_array_splitter.claim(state, _task_queue, stolen);
238 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array);
239 G1SkipCardMarkSetter x(&_scanner, dest_attr.is_new_survivor());
240 // Process claimed task.
241 to_array->oop_iterate_range(&_scanner,
242 checked_cast<int>(claim._start),
243 checked_cast<int>(claim._end));
244 }
245
246 MAYBE_INLINE_EVACUATION
247 void G1ParScanThreadState::start_partial_objarray(oop from_obj,
248 oop to_obj) {
249 assert(from_obj->is_forwarded(), "precondition");
250 assert(from_obj->forwardee() == to_obj, "precondition");
251 assert(to_obj->is_objArray(), "precondition");
252
253 objArrayOop to_array = objArrayOop(to_obj);
254 size_t array_length = to_array->length();
255 size_t initial_chunk_size =
256 // The source array is unused when processing states.
257 _partial_array_splitter.start(_task_queue, nullptr, to_array, array_length);
258
259 assert(_scanner.skip_card_mark_set(), "must be");
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 ALWAYSINLINE
426 void G1ParScanThreadState::do_iterate_object(oop const obj,
427 oop const old,
428 Klass* const klass,
429 G1HeapRegionAttr const region_attr,
430 G1HeapRegionAttr const dest_attr,
431 uint age) {
432 // Most objects are not arrays, so do one array check rather than
433 // checking for each array category for each object.
434 if (klass->is_array_klass()) {
435 assert(!klass->is_stack_chunk_instance_klass(), "must be");
436
437 if (klass->is_objArray_klass()) {
438 start_partial_objarray(old, obj);
439 } else {
440 // Nothing needs to be done for typeArrays. Body doesn't contain
441 // any oops to scan, and the type in the klass will already be handled
442 // by processing the built-in module.
443 assert(klass->is_typeArray_klass(), "invariant");
444 }
445 return;
446 }
447
448 ContinuationGCSupport::transform_stack_chunk(obj);
449
450 // Check for deduplicating young Strings.
451 if (G1StringDedup::is_candidate_from_evacuation(klass,
452 region_attr,
453 dest_attr,
454 age)) {
455 // Record old; request adds a new weak reference, which reference
456 // processing expects to refer to a from-space object.
457 _string_dedup_requests.add(old);
458 }
459
460 assert(_scanner.skip_card_mark_set(), "must be");
461 obj->oop_iterate_backwards(&_scanner, klass);
462 }
463
464 // Private inline function, for direct internal use and providing the
465 // implementation of the public not-inline function.
466 MAYBE_INLINE_EVACUATION
467 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr,
468 oop const old,
469 markWord const old_mark) {
470 assert(region_attr.is_in_cset(),
471 "Unexpected region attr type: %s", region_attr.get_type_str());
472
473 // NOTE: With compact headers, it is not safe to load the Klass* from old, because
474 // that would access the mark-word, that might change at any time by concurrent
475 // workers.
476 // This mark word would refer to a forwardee, which may not yet have completed
477 // copying. Therefore we must load the Klass* from the mark-word that we already
478 // loaded. This is safe, because we only enter here if not yet forwarded.
479 assert(!old_mark.is_forwarded(), "precondition");
480 Klass* klass = UseCompactObjectHeaders
481 ? old_mark.klass()
482 : old->klass();
483
484 const size_t word_sz = old->size_given_klass(klass);
485
486 // JNI only allows pinning of typeArrays, so we only need to keep those in place.
487 if (region_attr.is_pinned() && klass->is_typeArray_klass()) {
488 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, true /* cause_pinned */);
489 }
490
491 uint age = 0;
492 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age);
493 G1HeapRegion* const from_region = _g1h->heap_region_containing(old);
494 uint node_index = from_region->node_index();
495
496 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index);
497
498 // PLAB allocations should succeed most of the time, so we'll
499 // normally check against null once and that's it.
500 if (obj_ptr == nullptr) {
501 obj_ptr = allocate_copy_slow(&dest_attr, klass, word_sz, age, node_index);
502 if (obj_ptr == nullptr) {
503 // This will either forward-to-self, or detect that someone else has
504 // installed a forwarding pointer.
505 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, false /* cause_pinned */);
506 }
507 }
508
509 assert(obj_ptr != nullptr, "when we get here, allocation should have succeeded");
510 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");
511
512 // Should this evacuation fail?
513 if (inject_allocation_failure(from_region->hrm_index())) {
514 // Doing this after all the allocation attempts also tests the
515 // undo_allocation() method too.
516 undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
517 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, false /* cause_pinned */);
518 }
519
520 // We're going to allocate linearly, so might as well prefetch ahead.
521 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
522 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz);
523
524 const oop obj = cast_to_oop(obj_ptr);
525 // Because the forwarding is done with memory_order_relaxed there is no
526 // ordering with the above copy. Clients that get the forwardee must not
527 // examine its contents without other synchronization, since the contents
528 // may not be up to date for them.
529 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed);
530 if (forward_ptr == nullptr) {
531
532 {
533 const uint young_index = from_region->young_index_in_cset();
534 assert((from_region->is_young() && young_index > 0) ||
535 (!from_region->is_young() && young_index == 0), "invariant" );
536 _surviving_young_words[young_index] += word_sz;
537 }
538
539 if (dest_attr.is_young()) {
540 if (age < markWord::max_age) {
541 age++;
542 obj->incr_age();
543 }
544 _age_table.add(age, word_sz);
545 } else {
546 update_bot_after_copying(obj, word_sz);
547 }
548
549 {
550 // Skip the card enqueue iff the object (obj) is in survivor region.
551 // However, G1HeapRegion::is_survivor() is too expensive here.
552 // Instead, we use dest_attr.is_young() because the two values are always
553 // equal: successfully allocated young regions must be survivor regions.
554 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be");
555 G1SkipCardMarkSetter x(&_scanner, dest_attr.is_young());
556 do_iterate_object(obj, old, klass, region_attr, dest_attr, age);
557 }
558
559 return obj;
560 } else {
561 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
562 return forward_ptr;
563 }
564 }
565
566 // Public not-inline entry point.
567 ATTRIBUTE_FLATTEN
568 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr,
569 oop old,
570 markWord old_mark) {
571 return do_copy_to_survivor_space(region_attr, old, old_mark);
572 }
573
574 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) {
575 assert(worker_id < _num_workers, "out of bounds access");
576 if (_states[worker_id] == nullptr) {
577 _states[worker_id] =
578 new G1ParScanThreadState(_g1h,
579 worker_id,
580 _num_workers,
581 _collection_set,
582 _evac_failure_regions);
583 }
584 return _states[worker_id];
585 }
586
587 const size_t* G1ParScanThreadStateSet::surviving_young_words() const {
588 assert(_flushed, "thread local state from the per thread states should have been flushed");
589 return _surviving_young_words_total;
590 }
591
592 void G1ParScanThreadStateSet::flush_stats() {
593 assert(!_flushed, "thread local state from the per thread states should be flushed once");
594 for (uint worker_id = 0; worker_id < _num_workers; ++worker_id) {
595 G1ParScanThreadState* pss = _states[worker_id];
596 assert(pss != nullptr, "must be initialized");
597
598 G1GCPhaseTimes* p = _g1h->phase_times();
599
600 // Need to get the following two before the call to G1ParThreadScanState::flush()
601 // because it resets the PLAB allocator where we get this info from.
602 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize;
603 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize;
604 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _num_workers) * HeapWordSize;
605 size_t pending_cards = pss->num_cards_pending();
606 size_t to_young_gen_cards = pss->num_cards_marked() - pss->num_cards_pending();
607 size_t evac_failure_cards = pss->num_cards_from_evac_failure();
608 size_t marked_cards = pss->num_cards_marked();
609
610 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes);
611 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes);
612 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes);
613 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, pending_cards, G1GCPhaseTimes::MergePSSPendingCards);
614 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, to_young_gen_cards, G1GCPhaseTimes::MergePSSToYoungGenCards);
615 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, evac_failure_cards, G1GCPhaseTimes::MergePSSEvacFail);
616 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, marked_cards, G1GCPhaseTimes::MergePSSMarked);
617
618 delete pss;
619 _states[worker_id] = nullptr;
620 }
621
622 _flushed = true;
623 }
624
625 void G1ParScanThreadStateSet::record_unused_optional_region(G1HeapRegion* hr) {
626 for (uint worker_index = 0; worker_index < _num_workers; ++worker_index) {
627 G1ParScanThreadState* pss = _states[worker_index];
628 assert(pss != nullptr, "must be initialized");
629
630 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory();
631 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory);
632 }
633 }
634
635 void G1ParScanThreadState::record_evacuation_failed_region(G1HeapRegion* r, uint worker_id, bool cause_pinned) {
636 if (_evac_failure_regions->record(worker_id, r->hrm_index(), cause_pinned)) {
637 G1HeapRegionPrinter::evac_failure(r);
638 }
639 }
640
641 NOINLINE
642 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, Klass* klass, G1HeapRegionAttr attr, size_t word_sz, bool cause_pinned) {
643 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old));
644
645 oop forward_ptr = old->forward_to_self_atomic(m, memory_order_relaxed);
646 if (forward_ptr == nullptr) {
647 // Forward-to-self succeeded. We are the "owner" of the object.
648 G1HeapRegion* r = _g1h->heap_region_containing(old);
649
650 record_evacuation_failed_region(r, _worker_id, cause_pinned);
651
652 // Mark the failing object in the marking bitmap and later use the bitmap to handle
653 // evacuation failure recovery.
654 _g1h->mark_evac_failure_object(_worker_id, old, word_sz);
655
656 _evacuation_failed_info.register_copy_failure(word_sz);
657
658 {
659 // For iterating objects that failed evacuation currently we can reuse the
660 // existing closure to scan evacuated objects; since we are iterating from a
661 // collection set region (i.e. never a Survivor region), we always need to
662 // gather cards for this case.
663 G1SkipCardMarkSetter x(&_scanner, false /* skip_card_mark */);
664 do_iterate_object(old, old, klass, attr, attr, m.age());
665 }
666
667 return old;
668 } else {
669 // Forward-to-self failed. Either someone else managed to allocate
670 // space for this object (old != forward_ptr) or they beat us in
671 // self-forwarding it (old == forward_ptr).
672 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr),
673 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " "
674 "should not be in the CSet",
675 p2i(old), p2i(forward_ptr));
676 return forward_ptr;
677 }
678 }
679
680 void G1ParScanThreadState::initialize_numa_stats() {
681 if (_numa->is_enabled()) {
682 LogTarget(Info, gc, heap, numa) lt;
683
684 if (lt.is_enabled()) {
685 uint num_nodes = _numa->num_active_nodes();
686 // Record only if there are multiple active nodes.
687 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC);
688 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes);
689 }
690 }
691 }
692
693 void G1ParScanThreadState::flush_numa_stats() {
694 if (_obj_alloc_stat != nullptr) {
695 uint node_index = _numa->index_of_current_thread();
696 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat);
697 }
698 }
699
700 void G1ParScanThreadState::update_numa_stats(uint node_index) {
701 if (_obj_alloc_stat != nullptr) {
702 _obj_alloc_stat[node_index]++;
703 }
704 }
705
706 #if TASKQUEUE_STATS
707
708 PartialArrayTaskStats* G1ParScanThreadState::partial_array_task_stats() {
709 return _partial_array_splitter.stats();
710 }
711
712 #endif // TASKQUEUE_STATS
713
714 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h,
715 uint num_workers,
716 G1CollectionSet* collection_set,
717 G1EvacFailureRegions* evac_failure_regions) :
718 _g1h(g1h),
719 _collection_set(collection_set),
720 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, num_workers, mtGC)),
721 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, collection_set->young_region_length() + 1, mtGC)),
722 _num_workers(num_workers),
723 _flushed(false),
724 _evac_failure_regions(evac_failure_regions)
725 {
726 for (uint i = 0; i < num_workers; ++i) {
727 _states[i] = nullptr;
728 }
729 memset(_surviving_young_words_total, 0, (collection_set->young_region_length() + 1) * sizeof(size_t));
730 }
731
732 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() {
733 assert(_flushed, "thread local state from the per thread states should have been flushed");
734 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states);
735 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total);
736 }
737
738 #if TASKQUEUE_STATS
739
740 void G1ParScanThreadStateSet::print_partial_array_task_stats() {
741 auto get_stats = [&](uint i) {
742 return state_for_worker(i)->partial_array_task_stats();
743 };
744 PartialArrayTaskStats::log_set(_num_workers, get_stats,
745 "Partial Array Task Stats");
746 }
747
748 #endif // TASKQUEUE_STATS