1 /*
2 * Copyright (c) 2014, 2023, 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/g1YoungGCAllocationFailureInjector.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 num_workers,
62 G1CollectionSet* collection_set,
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(nullptr),
69 _plab_allocator(nullptr),
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(nullptr),
79 _surviving_young_words(nullptr),
80 _surviving_words_length(collection_set->young_region_length() + 1),
81 _old_gen_is_full(false),
82 _partial_objarray_chunk_size(ParGCArrayScanChunk),
83 _partial_array_stepper(num_workers),
84 _string_dedup_requests(),
85 _max_num_optional_regions(collection_set->optional_region_length()),
86 _numa(g1h->numa()),
87 _obj_alloc_stat(nullptr),
88 ALLOCATION_FAILURE_INJECTOR_ONLY(_allocation_failure_inject_counter(0) COMMA)
89 _preserved_marks(preserved_marks),
90 _evacuation_failed_info(),
91 _evac_failure_regions(evac_failure_regions),
92 _evac_failure_enqueued_cards(0)
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(_g1h,
108 this,
109 collection_set->only_contains_young_regions());
110
111 _oops_into_optional_regions = new G1OopStarChunkedList[_max_num_optional_regions];
112
113 initialize_numa_stats();
114 }
115
116 size_t G1ParScanThreadState::flush_stats(size_t* surviving_young_words, uint num_workers) {
117 _rdc_local_qset.flush();
118 flush_numa_stats();
119 // Update allocation statistics.
120 _plab_allocator->flush_and_retire_stats(num_workers);
121 _g1h->policy()->record_age_table(&_age_table);
122
123 if (_evacuation_failed_info.has_failed()) {
124 _g1h->gc_tracer_stw()->report_evacuation_failed(_evacuation_failed_info);
125 }
126
127 size_t sum = 0;
128 for (uint i = 0; i < _surviving_words_length; i++) {
129 surviving_young_words[i] += _surviving_young_words[i];
130 sum += _surviving_young_words[i];
131 }
132 return sum;
133 }
134
135 G1ParScanThreadState::~G1ParScanThreadState() {
136 delete _plab_allocator;
137 delete _closures;
138 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base);
139 delete[] _oops_into_optional_regions;
140 FREE_C_HEAP_ARRAY(size_t, _obj_alloc_stat);
141 }
142
143 size_t G1ParScanThreadState::lab_waste_words() const {
144 return _plab_allocator->waste();
145 }
146
147 size_t G1ParScanThreadState::lab_undo_waste_words() const {
148 return _plab_allocator->undo_waste();
149 }
150
151 size_t G1ParScanThreadState::evac_failure_enqueued_cards() const {
152 return _evac_failure_enqueued_cards;
153 }
154
155 #ifdef ASSERT
156 void G1ParScanThreadState::verify_task(narrowOop* task) const {
157 assert(task != nullptr, "invariant");
158 assert(UseCompressedOops, "sanity");
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(oop* task) const {
165 assert(task != nullptr, "invariant");
166 oop p = RawAccess<>::oop_load(task);
167 assert(_g1h->is_in_reserved(p),
168 "task=" PTR_FORMAT " p=" PTR_FORMAT, p2i(task), p2i(p));
169 }
170
171 void G1ParScanThreadState::verify_task(PartialArrayScanTask task) const {
172 // Must be in the collection set--it's already been copied.
173 oop p = task.to_source_array();
174 assert(_g1h->is_in_cset(p), "p=" PTR_FORMAT, p2i(p));
175 }
176
177 void G1ParScanThreadState::verify_task(ScannerTask task) const {
178 if (task.is_narrow_oop_ptr()) {
179 verify_task(task.to_narrow_oop_ptr());
180 } else if (task.is_oop_ptr()) {
181 verify_task(task.to_oop_ptr());
182 } else if (task.is_partial_array_task()) {
183 verify_task(task.to_partial_array_task());
184 } else {
185 ShouldNotReachHere();
186 }
187 }
188 #endif // ASSERT
189
190 template <class T>
191 MAYBE_INLINE_EVACUATION
192 void G1ParScanThreadState::do_oop_evac(T* p) {
193 // Reference should not be null here as such are never pushed to the task queue.
194 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
195
196 // Although we never intentionally push references outside of the collection
197 // set, due to (benign) races in the claim mechanism during RSet scanning more
198 // than one thread might claim the same card. So the same card may be
199 // processed multiple times, and so we might get references into old gen here.
200 // So we need to redo this check.
201 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
202 // References pushed onto the work stack should never point to a humongous region
203 // as they are not added to the collection set due to above precondition.
204 assert(!region_attr.is_humongous_candidate(),
205 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT,
206 p2i(obj), _g1h->addr_to_region(obj), p2i(p));
207
208 if (!region_attr.is_in_cset()) {
209 // In this case somebody else already did all the work.
210 return;
211 }
212
213 markWord m = obj->mark();
214 if (m.is_marked()) {
215 obj = cast_to_oop(m.decode_pointer());
216 } else {
217 obj = do_copy_to_survivor_space(region_attr, obj, m);
218 }
219 RawAccess<IS_NOT_NULL>::oop_store(p, obj);
220
221 write_ref_field_post(p, obj);
222 }
223
224 MAYBE_INLINE_EVACUATION
225 void G1ParScanThreadState::do_partial_array(PartialArrayScanTask task) {
226 oop from_obj = task.to_source_array();
227
228 assert(_g1h->is_in_reserved(from_obj), "must be in heap.");
229 assert(from_obj->is_objArray(), "must be obj array");
230 assert(from_obj->is_forwarded(), "must be forwarded");
231
232 oop to_obj = from_obj->forwardee();
233 assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
234 assert(to_obj->is_objArray(), "must be obj array");
235 objArrayOop to_array = objArrayOop(to_obj);
236
237 PartialArrayTaskStepper::Step step
238 = _partial_array_stepper.next(objArrayOop(from_obj),
239 to_array,
240 _partial_objarray_chunk_size);
241 for (uint i = 0; i < step._ncreate; ++i) {
242 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj)));
243 }
244
245 G1HeapRegionAttr dest_attr = _g1h->region_attr(to_array);
246 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_new_survivor());
247 // Process claimed task. The length of to_array is not correct, but
248 // fortunately the iteration ignores the length field and just relies
249 // on start/end.
250 to_array->oop_iterate_range(&_scanner,
251 step._index,
252 step._index + _partial_objarray_chunk_size);
253 }
254
255 MAYBE_INLINE_EVACUATION
256 void G1ParScanThreadState::start_partial_objarray(G1HeapRegionAttr dest_attr,
257 oop from_obj,
258 oop to_obj) {
259 assert(from_obj->is_objArray(), "precondition");
260 assert(from_obj->is_forwarded(), "precondition");
261 assert(from_obj->forwardee() == to_obj, "precondition");
262 assert(from_obj != to_obj, "should not be scanning self-forwarded objects");
263 assert(to_obj->is_objArray(), "precondition");
264
265 objArrayOop to_array = objArrayOop(to_obj);
266
267 PartialArrayTaskStepper::Step step
268 = _partial_array_stepper.start(objArrayOop(from_obj),
269 to_array,
270 _partial_objarray_chunk_size);
271
272 // Push any needed partial scan tasks. Pushed before processing the
273 // initial chunk to allow other workers to steal while we're processing.
274 for (uint i = 0; i < step._ncreate; ++i) {
275 push_on_queue(ScannerTask(PartialArrayScanTask(from_obj)));
276 }
277
278 // Skip the card enqueue iff the object (to_array) is in survivor region.
279 // However, HeapRegion::is_survivor() is too expensive here.
280 // Instead, we use dest_attr.is_young() because the two values are always
281 // equal: successfully allocated young regions must be survivor regions.
282 assert(dest_attr.is_young() == _g1h->heap_region_containing(to_array)->is_survivor(), "must be");
283 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young());
284 // Process the initial chunk. No need to process the type in the
285 // klass, as it will already be handled by processing the built-in
286 // module. The length of to_array is not correct, but fortunately
287 // the iteration ignores that length field and relies on start/end.
288 to_array->oop_iterate_range(&_scanner, 0, step._index);
289 }
290
291 MAYBE_INLINE_EVACUATION
292 void G1ParScanThreadState::dispatch_task(ScannerTask task) {
293 verify_task(task);
294 if (task.is_narrow_oop_ptr()) {
295 do_oop_evac(task.to_narrow_oop_ptr());
296 } else if (task.is_oop_ptr()) {
297 do_oop_evac(task.to_oop_ptr());
298 } else {
299 do_partial_array(task.to_partial_array_task());
300 }
301 }
302
303 // Process tasks until overflow queue is empty and local queue
304 // contains no more than threshold entries. NOINLINE to prevent
305 // inlining into steal_and_trim_queue.
306 ATTRIBUTE_FLATTEN NOINLINE
307 void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) {
308 ScannerTask task;
309 do {
310 while (_task_queue->pop_overflow(task)) {
311 if (!_task_queue->try_push_to_taskqueue(task)) {
312 dispatch_task(task);
313 }
314 }
315 while (_task_queue->pop_local(task, threshold)) {
316 dispatch_task(task);
317 }
318 } while (!_task_queue->overflow_empty());
319 }
320
321 ATTRIBUTE_FLATTEN
322 void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) {
323 ScannerTask stolen_task;
324 while (task_queues->steal(_worker_id, stolen_task)) {
325 dispatch_task(stolen_task);
326 // Processing stolen task may have added tasks to our queue.
327 trim_queue();
328 }
329 }
330
331 HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest,
332 size_t word_sz,
333 bool previous_plab_refill_failed,
334 uint node_index) {
335
336 assert(dest->is_in_cset_or_humongous_candidate(), "Unexpected dest: %s region attr", dest->get_type_str());
337
338 // Right now we only have two types of regions (young / old) so
339 // let's keep the logic here simple. We can generalize it when necessary.
340 if (dest->is_young()) {
341 bool plab_refill_in_old_failed = false;
342 HeapWord* const obj_ptr = _plab_allocator->allocate(G1HeapRegionAttr::Old,
343 word_sz,
344 &plab_refill_in_old_failed,
345 node_index);
346 // Make sure that we won't attempt to copy any other objects out
347 // of a survivor region (given that apparently we cannot allocate
348 // any new ones) to avoid coming into this slow path again and again.
349 // Only consider failed PLAB refill here: failed inline allocations are
350 // typically large, so not indicative of remaining space.
351 if (previous_plab_refill_failed) {
352 _tenuring_threshold = 0;
353 }
354
355 if (obj_ptr != nullptr) {
356 dest->set_old();
357 } else {
358 // We just failed to allocate in old gen. The same idea as explained above
359 // for making survivor gen unavailable for allocation applies for old gen.
360 _old_gen_is_full = plab_refill_in_old_failed;
361 }
362 return obj_ptr;
363 } else {
364 _old_gen_is_full = previous_plab_refill_failed;
365 assert(dest->is_old(), "Unexpected dest region attr: %s", dest->get_type_str());
366 // no other space to try.
367 return nullptr;
368 }
369 }
370
371 G1HeapRegionAttr G1ParScanThreadState::next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age) {
372 assert(region_attr.is_young() || region_attr.is_old(), "must be either Young or Old");
373
374 if (region_attr.is_young()) {
375 age = !m.has_displaced_mark_helper() ? m.age()
376 : m.displaced_mark_helper().age();
377 if (age < _tenuring_threshold) {
378 return region_attr;
379 }
380 }
381 // young-to-old (promotion) or old-to-old; destination is old in both cases.
382 return G1HeapRegionAttr::Old;
383 }
384
385 void G1ParScanThreadState::report_promotion_event(G1HeapRegionAttr const dest_attr,
386 oop const old, size_t word_sz, uint age,
387 HeapWord * const obj_ptr, uint node_index) const {
388 PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_attr, node_index);
389 if (alloc_buf->contains(obj_ptr)) {
390 _g1h->gc_tracer_stw()->report_promotion_in_new_plab_event(old->klass(), word_sz * HeapWordSize, age,
391 dest_attr.type() == G1HeapRegionAttr::Old,
392 alloc_buf->word_sz() * HeapWordSize);
393 } else {
394 _g1h->gc_tracer_stw()->report_promotion_outside_plab_event(old->klass(), word_sz * HeapWordSize, age,
395 dest_attr.type() == G1HeapRegionAttr::Old);
396 }
397 }
398
399 NOINLINE
400 HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr,
401 oop old,
402 size_t word_sz,
403 uint age,
404 uint node_index) {
405 HeapWord* obj_ptr = nullptr;
406 // Try slow-path allocation unless we're allocating old and old is already full.
407 if (!(dest_attr->is_old() && _old_gen_is_full)) {
408 bool plab_refill_failed = false;
409 obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr,
410 word_sz,
411 &plab_refill_failed,
412 node_index);
413 if (obj_ptr == nullptr) {
414 obj_ptr = allocate_in_next_plab(dest_attr,
415 word_sz,
416 plab_refill_failed,
417 node_index);
418 }
419 }
420 if (obj_ptr != nullptr) {
421 update_numa_stats(node_index);
422 if (_g1h->gc_tracer_stw()->should_report_promotion_events()) {
423 // The events are checked individually as part of the actual commit
424 report_promotion_event(*dest_attr, old, word_sz, age, obj_ptr, node_index);
425 }
426 }
427 return obj_ptr;
428 }
429
430 #if ALLOCATION_FAILURE_INJECTOR
431 bool G1ParScanThreadState::inject_allocation_failure(uint region_idx) {
432 return _g1h->allocation_failure_injector()->allocation_should_fail(_allocation_failure_inject_counter, region_idx);
433 }
434 #endif
435
436 NOINLINE
437 void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr,
438 HeapWord* obj_ptr,
439 size_t word_sz,
440 uint node_index) {
441 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
442 }
443
444 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) {
445 HeapWord* obj_start = cast_from_oop<HeapWord*>(obj);
446 HeapRegion* region = _g1h->heap_region_containing(obj_start);
447 region->update_bot_for_obj(obj_start, word_sz);
448 }
449
450 // Private inline function, for direct internal use and providing the
451 // implementation of the public not-inline function.
452 MAYBE_INLINE_EVACUATION
453 oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr,
454 oop const old,
455 markWord const old_mark) {
456 assert(region_attr.is_in_cset(),
457 "Unexpected region attr type: %s", region_attr.get_type_str());
458
459 // Get the klass once. We'll need it again later, and this avoids
460 // re-decoding when it's compressed.
461 Klass* klass = old->klass();
462 const size_t word_sz = old->size_given_klass(klass);
463
464 // JNI only allows pinning of typeArrays, so we only need to keep those in place.
465 if (region_attr.is_pinned() && klass->is_typeArray_klass()) {
466 return handle_evacuation_failure_par(old, old_mark, word_sz, true /* cause_pinned */);
467 }
468
469 uint age = 0;
470 G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age);
471 HeapRegion* const from_region = _g1h->heap_region_containing(old);
472 uint node_index = from_region->node_index();
473
474 HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index);
475
476 // PLAB allocations should succeed most of the time, so we'll
477 // normally check against null once and that's it.
478 if (obj_ptr == nullptr) {
479 obj_ptr = allocate_copy_slow(&dest_attr, old, word_sz, age, node_index);
480 if (obj_ptr == nullptr) {
481 // This will either forward-to-self, or detect that someone else has
482 // installed a forwarding pointer.
483 return handle_evacuation_failure_par(old, old_mark, word_sz, false /* cause_pinned */);
484 }
485 }
486
487 assert(obj_ptr != nullptr, "when we get here, allocation should have succeeded");
488 assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");
489
490 // Should this evacuation fail?
491 if (inject_allocation_failure(from_region->hrm_index())) {
492 // Doing this after all the allocation attempts also tests the
493 // undo_allocation() method too.
494 undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
495 return handle_evacuation_failure_par(old, old_mark, word_sz, false /* cause_pinned */);
496 }
497
498 // We're going to allocate linearly, so might as well prefetch ahead.
499 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
500 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz);
501
502 const oop obj = cast_to_oop(obj_ptr);
503 // Because the forwarding is done with memory_order_relaxed there is no
504 // ordering with the above copy. Clients that get the forwardee must not
505 // examine its contents without other synchronization, since the contents
506 // may not be up to date for them.
507 const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed);
508 if (forward_ptr == nullptr) {
509
510 {
511 const uint young_index = from_region->young_index_in_cset();
512 assert((from_region->is_young() && young_index > 0) ||
513 (!from_region->is_young() && young_index == 0), "invariant" );
514 _surviving_young_words[young_index] += word_sz;
515 }
516
517 if (dest_attr.is_young()) {
518 if (age < markWord::max_age) {
519 age++;
520 obj->incr_age();
521 }
522 _age_table.add(age, word_sz);
523 } else {
524 update_bot_after_copying(obj, word_sz);
525 }
526
527 // Most objects are not arrays, so do one array check rather than
528 // checking for each array category for each object.
529 if (klass->is_array_klass()) {
530 if (klass->is_objArray_klass()) {
531 start_partial_objarray(dest_attr, old, obj);
532 } else {
533 // Nothing needs to be done for typeArrays. Body doesn't contain
534 // any oops to scan, and the type in the klass will already be handled
535 // by processing the built-in module.
536 assert(klass->is_typeArray_klass(), "invariant");
537 }
538 return obj;
539 }
540
541 ContinuationGCSupport::transform_stack_chunk(obj);
542
543 // Check for deduplicating young Strings.
544 if (G1StringDedup::is_candidate_from_evacuation(klass,
545 region_attr,
546 dest_attr,
547 age)) {
548 // Record old; request adds a new weak reference, which reference
549 // processing expects to refer to a from-space object.
550 _string_dedup_requests.add(old);
551 }
552
553 // Skip the card enqueue iff the object (obj) is in survivor region.
554 // However, HeapRegion::is_survivor() is too expensive here.
555 // Instead, we use dest_attr.is_young() because the two values are always
556 // equal: successfully allocated young regions must be survivor regions.
557 assert(dest_attr.is_young() == _g1h->heap_region_containing(obj)->is_survivor(), "must be");
558 G1SkipCardEnqueueSetter x(&_scanner, dest_attr.is_young());
559 obj->oop_iterate_backwards(&_scanner, klass);
560 return obj;
561 } else {
562 _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
563 return forward_ptr;
564 }
565 }
566
567 // Public not-inline entry point.
568 ATTRIBUTE_FLATTEN
569 oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr,
570 oop old,
571 markWord old_mark) {
572 return do_copy_to_survivor_space(region_attr, old, old_mark);
573 }
574
575 G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) {
576 assert(worker_id < _num_workers, "out of bounds access");
577 if (_states[worker_id] == nullptr) {
578 _states[worker_id] =
579 new G1ParScanThreadState(_g1h, rdcqs(),
580 _preserved_marks_set.get(worker_id),
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
597 for (uint worker_id = 0; worker_id < _num_workers; ++worker_id) {
598 G1ParScanThreadState* pss = _states[worker_id];
599 assert(pss != nullptr, "must be initialized");
600
601 G1GCPhaseTimes* p = _g1h->phase_times();
602
603 // Need to get the following two before the call to G1ParThreadScanState::flush()
604 // because it resets the PLAB allocator where we get this info from.
605 size_t lab_waste_bytes = pss->lab_waste_words() * HeapWordSize;
606 size_t lab_undo_waste_bytes = pss->lab_undo_waste_words() * HeapWordSize;
607 size_t copied_bytes = pss->flush_stats(_surviving_young_words_total, _num_workers) * HeapWordSize;
608 size_t evac_fail_enqueued_cards = pss->evac_failure_enqueued_cards();
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, evac_fail_enqueued_cards, G1GCPhaseTimes::MergePSSEvacFailExtra);
614
615 delete pss;
616 _states[worker_id] = nullptr;
617 }
618 _flushed = true;
619 }
620
621 void G1ParScanThreadStateSet::record_unused_optional_region(HeapRegion* hr) {
622 for (uint worker_index = 0; worker_index < _num_workers; ++worker_index) {
623 G1ParScanThreadState* pss = _states[worker_index];
624 assert(pss != nullptr, "must be initialized");
625
626 size_t used_memory = pss->oops_into_optional_region(hr)->used_memory();
627 _g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory);
628 }
629 }
630
631 NOINLINE
632 oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m, size_t word_sz, bool cause_pinned) {
633 assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old));
634
635 oop forward_ptr = old->forward_to_atomic(old, m, memory_order_relaxed);
636 if (forward_ptr == nullptr) {
637 // Forward-to-self succeeded. We are the "owner" of the object.
638 HeapRegion* r = _g1h->heap_region_containing(old);
639
640 if (_evac_failure_regions->record(_worker_id, r->hrm_index(), cause_pinned)) {
641 _g1h->hr_printer()->evac_failure(r);
642 }
643
644 // Mark the failing object in the marking bitmap and later use the bitmap to handle
645 // evacuation failure recovery.
646 _g1h->mark_evac_failure_object(_worker_id, old, word_sz);
647
648 _preserved_marks->push_if_necessary(old, m);
649
650 ContinuationGCSupport::transform_stack_chunk(old);
651
652 _evacuation_failed_info.register_copy_failure(word_sz);
653
654 // For iterating objects that failed evacuation currently we can reuse the
655 // existing closure to scan evacuated objects; since we are iterating from a
656 // collection set region (i.e. never a Survivor region), we always need to
657 // gather cards for this case.
658 G1SkipCardEnqueueSetter x(&_scanner, false /* skip_card_enqueue */);
659 old->oop_iterate_backwards(&_scanner);
660
661 return old;
662 } else {
663 // Forward-to-self failed. Either someone else managed to allocate
664 // space for this object (old != forward_ptr) or they beat us in
665 // self-forwarding it (old == forward_ptr).
666 assert(old == forward_ptr || !_g1h->is_in_cset(forward_ptr),
667 "Object " PTR_FORMAT " forwarded to: " PTR_FORMAT " "
668 "should not be in the CSet",
669 p2i(old), p2i(forward_ptr));
670 return forward_ptr;
671 }
672 }
673
674 void G1ParScanThreadState::initialize_numa_stats() {
675 if (_numa->is_enabled()) {
676 LogTarget(Info, gc, heap, numa) lt;
677
678 if (lt.is_enabled()) {
679 uint num_nodes = _numa->num_active_nodes();
680 // Record only if there are multiple active nodes.
681 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC);
682 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes);
683 }
684 }
685 }
686
687 void G1ParScanThreadState::flush_numa_stats() {
688 if (_obj_alloc_stat != nullptr) {
689 uint node_index = _numa->index_of_current_thread();
690 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat);
691 }
692 }
693
694 void G1ParScanThreadState::update_numa_stats(uint node_index) {
695 if (_obj_alloc_stat != nullptr) {
696 _obj_alloc_stat[node_index]++;
697 }
698 }
699
700 G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h,
701 uint num_workers,
702 G1CollectionSet* collection_set,
703 G1EvacFailureRegions* evac_failure_regions) :
704 _g1h(g1h),
705 _collection_set(collection_set),
706 _rdcqs(G1BarrierSet::dirty_card_queue_set().allocator()),
707 _preserved_marks_set(true /* in_c_heap */),
708 _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, num_workers, mtGC)),
709 _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, collection_set->young_region_length() + 1, mtGC)),
710 _num_workers(num_workers),
711 _flushed(false),
712 _evac_failure_regions(evac_failure_regions) {
713 _preserved_marks_set.init(num_workers);
714 for (uint i = 0; i < num_workers; ++i) {
715 _states[i] = nullptr;
716 }
717 memset(_surviving_young_words_total, 0, (collection_set->young_region_length() + 1) * sizeof(size_t));
718 }
719
720 G1ParScanThreadStateSet::~G1ParScanThreadStateSet() {
721 assert(_flushed, "thread local state from the per thread states should have been flushed");
722 FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states);
723 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total);
724 _preserved_marks_set.reclaim();
725 }