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 assert(to_array->is_refArray(), "Must be");
242 refArrayOop(to_array)->oop_iterate_range(&_scanner,
243 checked_cast<int>(claim._start),
244 checked_cast<int>(claim._end));
245 }
246
247 MAYBE_INLINE_EVACUATION
248 void G1ParScanThreadState::start_partial_objarray(oop from_obj,
249 oop to_obj) {
250 assert(from_obj->is_forwarded(), "precondition");
251 assert(from_obj->forwardee() == to_obj, "precondition");
252 assert(to_obj->is_objArray(), "precondition");
253
254 objArrayOop to_array = objArrayOop(to_obj);
255 size_t array_length = to_array->length();
256 size_t initial_chunk_size =
257 // The source array is unused when processing states.
258 _partial_array_splitter.start(_task_queue, nullptr, to_array, array_length);
259
260 assert(_scanner.skip_card_mark_set(), "must be");
261 // Process the initial chunk. No need to process the type in the
262 // klass, as it will already be handled by processing the built-in
263 // module.
264 assert(to_array->is_refArray(), "Must be");
265 refArrayOop(to_array)->oop_iterate_range(&_scanner, 0, checked_cast<int>(initial_chunk_size));
266 }
267
268 MAYBE_INLINE_EVACUATION
269 void G1ParScanThreadState::dispatch_task(ScannerTask task, bool stolen) {
270 verify_task(task);
271 if (task.is_narrow_oop_ptr()) {
272 do_oop_evac(task.to_narrow_oop_ptr());
273 } else if (task.is_oop_ptr()) {
274 do_oop_evac(task.to_oop_ptr());
275 } else {
276 do_partial_array(task.to_partial_array_state(), stolen);
277 }
278 }
279
280 // Process tasks until overflow queue is empty and local queue
281 // contains no more than threshold entries. NOINLINE to prevent
282 // inlining into steal_and_trim_queue.
283 ATTRIBUTE_FLATTEN NOINLINE
284 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) {
285 ScannerTask task;
286 do {
287 while (_task_queue->pop_overflow(task)) {
288 if (!_task_queue->try_push_to_taskqueue(task)) {
289 dispatch_task(task, false);
290 }
291 }
292 while (_task_queue->pop_local(task, threshold)) {
293 dispatch_task(task, false);
294 }
295 } while (!_task_queue->overflow_empty());
296 }
297
298 ATTRIBUTE_FLATTEN
299 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) {
300 ScannerTask stolen_task;
301 while (task_queues->steal(_worker_id, stolen_task)) {
302 dispatch_task(stolen_task, true);
303 // Processing stolen task may have added tasks to our queue.
304 trim_queue();
305 }
306 }
307
308 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest,
309 size_t word_sz,
310 bool previous_plab_refill_failed,
311 uint node_index) {
312
313 assert(dest->is_in_cset_or_humongous_candidate(), "Unexpected dest: %s region attr", dest->get_type_str());
314
315 // Right now we only have two types of regions (young / old) so
316 // let's keep the logic here simple. We can generalize it when necessary.
317 if (dest->is_young()) {
318 bool plab_refill_in_old_failed = false;
319 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old,
320 word_sz,
321 &plab_refill_in_old_failed,
322 node_index);
323 // Make sure that we won't attempt to copy any other objects out
324 // of a survivor region (given that apparently we cannot allocate
325 // any new ones) to avoid coming into this slow path again and again.
326 // Only consider failed PLAB refill here: failed inline allocations are
327 // typically large, so not indicative of remaining space.
328 if (previous_plab_refill_failed) {
329 _tenuring_threshold = 0;
330 }
331
332 if (obj_ptr != nullptr) {
333 dest->set_old();
334 } else {
335 // We just failed to allocate in old gen. The same idea as explained above
336 // for making survivor gen unavailable for allocation applies for old gen.
337 _old_gen_is_full = plab_refill_in_old_failed;
338 }
339 return obj_ptr;
340 } else {
341 _old_gen_is_full = previous_plab_refill_failed;
342 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str());
343 // no other space to try.
344 return nullptr;
345 }
346 }
347
348 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) {
349 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old");
350
351 if (region_attr.is_young()) {
352 age = !m.has_displaced_mark_helper() ? m.age()
353 : m.displaced_mark_helper().age();
354 if (age < _tenuring_threshold) {
355 return region_attr;
356 }
357 }
358 // young-to-old (promotion) or old-to-old; destination is old in both cases.
359 return G1HeapRegionAttr::Old;
360 }
361
362 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr,
363 Klass* klass, size_t word_sz, uint age,
364 HeapWord * const obj_ptr, uint node_index) const {
365 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index);
366 if (alloc_buf->contains(obj_ptr)) {
367 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(klass, word_sz * HeapWordSize, age,
368 dest_attr.type() == G1HeapRegionAttr::Old,
369 alloc_buf->word_sz() * HeapWordSize);
370 } else {
371 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(klass, word_sz * HeapWordSize, age,
372 dest_attr.type() == G1HeapRegionAttr::Old);
373 }
374 }
375
376 NOINLINE
377 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr,
378 Klass* klass,
379 size_t word_sz,
380 uint age,
381 uint node_index) {
382 HeapWord* obj_ptr = nullptr;
383 // Try slow-path allocation unless we're allocating old and old is already full.
384 if (!(dest_attr->is_old() && _old_gen_is_full)) {
385 bool plab_refill_failed = false;
386 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr,
387 word_sz,
388 &plab_refill_failed,
389 node_index);
390 if (obj_ptr == nullptr) {
391 obj_ptr = allocate_in_next_plab(dest_attr,
392 word_sz,
393 plab_refill_failed,
394 node_index);
395 }
396 }
397 if (obj_ptr != nullptr) {
398 update_numa_stats(node_index);
399 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) {
400 // The events are checked individually as part of the actual commit
401 report_promotion_event(*dest_attr, klass, word_sz, age, obj_ptr, node_index);
402 }
403 }
404 return obj_ptr;
405 }
406
407 #if ALLOCATION_FAILURE_INJECTOR
408 bool G1ParScanThreadState::inject_allocation_failure(uint region_idx) {
409 return _g1h->allocation_failure_injector()->allocation_should_fail(_allocation_failure_inject_counter, region_idx);
410 }
411 #endif
412
413 NOINLINE
414 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr,
415 HeapWord* obj_ptr,
416 size_t word_sz,
417 uint node_index) {
418 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
419 }
420
421 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) {
422 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj);
423 G1HeapRegion* region = _g1h->heap_region_containing(obj_start);
424 region->update_bot_for_block(obj_start, obj_start + word_sz);
425 }
426
427 ALWAYSINLINE
428 void G1ParScanThreadState::do_iterate_object(oop const obj,
429 oop const old,
430 Klass* const klass,
431 G1HeapRegionAttr const region_attr,
432 G1HeapRegionAttr const dest_attr,
433 uint age) {
434 // Most objects are not arrays, so do one array check rather than
435 // checking for each array category for each object.
436 if (klass->is_array_klass() && !klass->is_flatArray_klass()) {
437 assert(!klass->is_stack_chunk_instance_klass(), "must be");
438
439 if (klass->is_refArray_klass()) {
440 start_partial_objarray(old, obj);
441 } else {
442 // Nothing needs to be done for typeArrays. Body doesn't contain
443 // any oops to scan, and the type in the klass will already be handled
444 // by processing the built-in module.
445 assert(klass->is_typeArray_klass() || klass->is_objArray_klass(), "invariant");
446 }
447 return;
448 }
449
450 ContinuationGCSupport::transform_stack_chunk(obj);
451
452 // Check for deduplicating young Strings.
453 if (G1StringDedup::is_candidate_from_evacuation(klass,
454 region_attr,
455 dest_attr,
456 age)) {
457 // Record old; request adds a new weak reference, which reference
458 // processing expects to refer to a from-space object.
459 _string_dedup_requests.add(old);
460 }
461
462 assert(_scanner.skip_card_mark_set(), "must be");
463 obj->oop_iterate_backwards(&_scanner, klass);
464 }
465
466 // Private inline function, for direct internal use and providing the
467 // implementation of the public not-inline function.
468 MAYBE_INLINE_EVACUATION
469 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr,
470 oop const old,
471 markWord const old_mark) {
472 assert(region_attr.is_in_cset(),
473 "Unexpected region attr type: %s", region_attr.get_type_str());
474
475 // NOTE: With compact headers, it is not safe to load the Klass* from old, because
476 // that would access the mark-word, that might change at any time by concurrent
477 // workers.
478 // This mark word would refer to a forwardee, which may not yet have completed
479 // copying. Therefore we must load the Klass* from the mark-word that we already
480 // loaded. This is safe, because we only enter here if not yet forwarded.
481 assert(!old_mark.is_forwarded(), "precondition");
482 Klass* klass = UseCompactObjectHeaders
483 ? old_mark.klass()
484 : old->klass();
485
486 const size_t word_sz = old->size_given_klass(klass);
487
488 // JNI only allows pinning of typeArrays, so we only need to keep those in place.
489 if (region_attr.is_pinned() && klass->is_typeArray_klass()) {
490 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, true /* cause_pinned */);
491 }
492
493 uint age = 0;
494 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age);
495 G1HeapRegion* const from_region = _g1h->heap_region_containing(old);
496 uint node_index = from_region->node_index();
497
498 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index);
499
500 // PLAB allocations should succeed most of the time, so we'll
501 // normally check against null once and that's it.
502 if (obj_ptr == nullptr) {
503 obj_ptr = allocate_copy_slow(&dest_attr, klass, word_sz, age, node_index);
504 if (obj_ptr == nullptr) {
505 // This will either forward-to-self, or detect that someone else has
506 // installed a forwarding pointer.
507 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, false /* cause_pinned */);
508 }
509 }
510
511 assert(obj_ptr != nullptr, "when we get here, allocation should have succeeded");
512 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");
513
514 // Should this evacuation fail?
515 if (inject_allocation_failure(from_region->hrm_index())) {
516 // Doing this after all the allocation attempts also tests the
517 // undo_allocation() method too.
518 undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
519 return handle_evacuation_failure_par(old, old_mark, klass, region_attr, word_sz, false /* cause_pinned */);
520 }
521
522 // We're going to allocate linearly, so might as well prefetch ahead.
523 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
524 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz);
525
526 const oop obj = cast_to_oop(obj_ptr);
527 // Because the forwarding is done with memory_order_relaxed there is no
528 // ordering with the above copy. Clients that get the forwardee must not
529 // examine its contents without other synchronization, since the contents
530 // may not be up to date for them.
531 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed);
532 if (forward_ptr == nullptr) {
533
534 {
535 const uint young_index = from_region->young_index_in_cset();
536 assert((from_region->is_young() && young_index > 0) ||
537 (!from_region->is_young() && young_index == 0), "invariant" );
538 _surviving_young_words[young_index] += word_sz;
539 }
540
541 if (dest_attr.is_young()) {
542 if (age < markWord::max_age) {
543 age++;
544 obj->incr_age();
545 }
546 _age_table.add(age, word_sz);
547 } else {
548 update_bot_after_copying(obj, word_sz);
549 }
550
551 {
552 // Skip the card enqueue iff the object (obj) is in survivor region.
553 // However, G1HeapRegion::is_survivor() is too expensive here.
554 // Instead, we use dest_attr.is_young() because the two values are always
555 // equal: successfully allocated young regions must be survivor regions.
556 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be");
557 G1SkipCardMarkSetter x(&_scanner, dest_attr.is_young());
558 do_iterate_object(obj, old, klass, region_attr, dest_attr, age);
559 }
560
561 return obj;
562 } else {
563 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
564 return forward_ptr;
565 }
566 }
567
568 // Public not-inline entry point.
569 ATTRIBUTE_FLATTEN
570 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr,
571 oop old,
572 markWord old_mark) {
573 return do_copy_to_survivor_space(region_attr, old, old_mark);
574 }
575
576 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) {
577 assert(worker_id < _num_workers, "out of bounds access");
578 if (_states[worker_id] == nullptr) {
579 _states[worker_id] =
580 new G1ParScanThreadState(_g1h,
581 worker_id,
582 _num_workers,
583 _collection_set,
584 _evac_failure_regions);
585 }
586 return _states[worker_id];
587 }
588
589 const size_t* G1ParScanThreadStateSet::surviving_young_words() const {
590 assert(_flushed, "thread local state from the per thread states should have been flushed");
591 return _surviving_young_words_total;
592 }
593
594 void G1ParScanThreadStateSet::flush_stats() {
595 assert(!_flushed, "thread local state from the per thread states should be flushed once");
596 for (uint worker_id = 0; worker_id < _num_workers; ++worker_id) {
597 G1ParScanThreadState* pss = _states[worker_id];
598 assert(pss != nullptr, "must be initialized");
599
600 G1GCPhaseTimes* p = _g1h->phase_times();
601
602 // Need to get the following two before the call to G1ParThreadScanState::flush()
603 // because it resets the PLAB allocator where we get this info from.
604 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize;
605 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize;
606 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _num_workers) * HeapWordSize;
607 size_t pending_cards = pss->num_cards_pending();
608 size_t to_young_gen_cards = pss->num_cards_marked() - pss->num_cards_pending();
609 size_t evac_failure_cards = pss->num_cards_from_evac_failure();
610 size_t marked_cards = pss->num_cards_marked();
611
612 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, copied_bytes, G1GCPhaseTimes::MergePSSCopiedBytes);
613 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_waste_bytes, G1GCPhaseTimes::MergePSSLABWasteBytes);
614 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, lab_undo_waste_bytes, G1GCPhaseTimes::MergePSSLABUndoWasteBytes);
615 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, pending_cards, G1GCPhaseTimes::MergePSSPendingCards);
616 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, to_young_gen_cards, G1GCPhaseTimes::MergePSSToYoungGenCards);
617 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, evac_failure_cards, G1GCPhaseTimes::MergePSSEvacFail);
618 p->record_or_add_thread_work_item(G1GCPhaseTimes::MergePSS, worker_id, marked_cards, G1GCPhaseTimes::MergePSSMarked);
619
620 delete pss;
621 _states[worker_id] = nullptr;
622 }
623
624 _flushed = true;
625 }
626
627 void G1ParScanThreadStateSet::record_unused_optional_region(G1HeapRegion* hr) {
628 for (uint worker_index = 0; worker_index < _num_workers; ++worker_index) {
629 G1ParScanThreadState* pss = _states[worker_index];
630 assert(pss != nullptr, "must be initialized");
631
632 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory();
633 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory);
634 }
635 }
636
637 void G1ParScanThreadState::record_evacuation_failed_region(G1HeapRegion* r, uint worker_id, bool cause_pinned) {
638 if (_evac_failure_regions->record(worker_id, r->hrm_index(), cause_pinned)) {
639 G1HeapRegionPrinter::evac_failure(r);
640 }
641 }
642
643 NOINLINE
644 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, Klass* klass, G1HeapRegionAttr attr, size_t word_sz, bool cause_pinned) {
645 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old));
646
647 oop forward_ptr = old->forward_to_self_atomic(m, memory_order_relaxed);
648 if (forward_ptr == nullptr) {
649 // Forward-to-self succeeded. We are the "owner" of the object.
650 G1HeapRegion* r = _g1h->heap_region_containing(old);
651
652 record_evacuation_failed_region(r, _worker_id, cause_pinned);
653
654 // Mark the failing object in the marking bitmap and later use the bitmap to handle
655 // evacuation failure recovery.
656 _g1h->mark_evac_failure_object(_worker_id, old, word_sz);
657
658 _evacuation_failed_info.register_copy_failure(word_sz);
659
660 {
661 // For iterating objects that failed evacuation currently we can reuse the
662 // existing closure to scan evacuated objects; since we are iterating from a
663 // collection set region (i.e. never a Survivor region), we always need to
664 // gather cards for this case.
665 G1SkipCardMarkSetter x(&_scanner, false /* skip_card_mark */);
666 do_iterate_object(old, old, klass, attr, attr, m.age());
667 }
668
669 return old;
670 } else {
671 // Forward-to-self failed. Either someone else managed to allocate
672 // space for this object (old != forward_ptr) or they beat us in
673 // self-forwarding it (old == forward_ptr).
674 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr),
675 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " "
676 "should not be in the CSet",
677 p2i(old), p2i(forward_ptr));
678 return forward_ptr;
679 }
680 }
681
682 void G1ParScanThreadState::initialize_numa_stats() {
683 if (_numa->is_enabled()) {
684 LogTarget(Info, gc, heap, numa) lt;
685
686 if (lt.is_enabled()) {
687 uint num_nodes = _numa->num_active_nodes();
688 // Record only if there are multiple active nodes.
689 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC);
690 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes);
691 }
692 }
693 }
694
695 void G1ParScanThreadState::flush_numa_stats() {
696 if (_obj_alloc_stat != nullptr) {
697 uint node_index = _numa->index_of_current_thread();
698 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat);
699 }
700 }
701
702 void G1ParScanThreadState::update_numa_stats(uint node_index) {
703 if (_obj_alloc_stat != nullptr) {
704 _obj_alloc_stat[node_index]++;
705 }
706 }
707
708 #if TASKQUEUE_STATS
709
710 PartialArrayTaskStats* G1ParScanThreadState::partial_array_task_stats() {
711 return _partial_array_splitter.stats();
712 }
713
714 #endif // TASKQUEUE_STATS
715
716 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h,
717 uint num_workers,
718 G1CollectionSet* collection_set,
719 G1EvacFailureRegions* evac_failure_regions) :
720 _g1h(g1h),
721 _collection_set(collection_set),
722 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, num_workers, mtGC)),
723 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, collection_set->young_region_length() + 1, mtGC)),
724 _num_workers(num_workers),
725 _flushed(false),
726 _evac_failure_regions(evac_failure_regions)
727 {
728 for (uint i = 0; i < num_workers; ++i) {
729 _states[i] = nullptr;
730 }
731 memset(_surviving_young_words_total, 0, (collection_set->young_region_length() + 1) * sizeof(size_t));
732 }
733
734 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() {
735 assert(_flushed, "thread local state from the per thread states should have been flushed");
736 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states);
737 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total);
738 }
739
740 #if TASKQUEUE_STATS
741
742 void G1ParScanThreadStateSet::print_partial_array_task_stats() {
743 auto get_stats = [&](uint i) {
744 return state_for_worker(i)->partial_array_task_stats();
745 };
746 PartialArrayTaskStats::log_set(_num_workers, get_stats,
747 "Partial Array Task Stats");
748 }
749
750 #endif // TASKQUEUE_STATS