1 /*
2 * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2013, 2020, Red Hat, Inc. All rights reserved.
4 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "precompiled.hpp"
28 #include "gc/shared/cardTable.hpp"
29 #include "gc/shared/space.inline.hpp"
30 #include "gc/shared/tlab_globals.hpp"
31 #include "gc/shenandoah/shenandoahCardTable.hpp"
32 #include "gc/shenandoah/shenandoahFreeSet.hpp"
33 #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
34 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
35 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
36 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
37 #include "gc/shenandoah/shenandoahOldGeneration.hpp"
38 #include "gc/shenandoah/shenandoahGeneration.hpp"
39 #include "gc/shenandoah/shenandoahYoungGeneration.hpp"
40 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
41 #include "jfr/jfrEvents.hpp"
42 #include "memory/allocation.hpp"
43 #include "memory/iterator.inline.hpp"
44 #include "memory/resourceArea.hpp"
45 #include "memory/universe.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "runtime/atomic.hpp"
48 #include "runtime/globals_extension.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/mutexLocker.hpp"
51 #include "runtime/os.hpp"
52 #include "runtime/safepoint.hpp"
53 #include "utilities/powerOfTwo.hpp"
54
55
56 size_t ShenandoahHeapRegion::RegionCount = 0;
57 size_t ShenandoahHeapRegion::RegionSizeBytes = 0;
58 size_t ShenandoahHeapRegion::RegionSizeWords = 0;
59 size_t ShenandoahHeapRegion::RegionSizeBytesShift = 0;
60 size_t ShenandoahHeapRegion::RegionSizeWordsShift = 0;
61 size_t ShenandoahHeapRegion::RegionSizeBytesMask = 0;
62 size_t ShenandoahHeapRegion::RegionSizeWordsMask = 0;
63 size_t ShenandoahHeapRegion::MaxTLABSizeBytes = 0;
64 size_t ShenandoahHeapRegion::MaxTLABSizeWords = 0;
65
66 ShenandoahHeapRegion::ShenandoahHeapRegion(HeapWord* start, size_t index, bool committed) :
67 _index(index),
68 _bottom(start),
69 _end(start + RegionSizeWords),
70 _new_top(nullptr),
71 _empty_time(os::elapsedTime()),
72 _top_before_promoted(nullptr),
73 _state(committed ? _empty_committed : _empty_uncommitted),
74 _top(start),
75 _tlab_allocs(0),
76 _gclab_allocs(0),
77 _plab_allocs(0),
78 _live_data(0),
79 _critical_pins(0),
80 _update_watermark(start),
81 _age(0)
82 #ifdef SHENANDOAH_CENSUS_NOISE
83 , _youth(0)
84 #endif // SHENANDOAH_CENSUS_NOISE
85 {
86
87 assert(Universe::on_page_boundary(_bottom) && Universe::on_page_boundary(_end),
88 "invalid space boundaries");
89 if (ZapUnusedHeapArea && committed) {
90 SpaceMangler::mangle_region(MemRegion(_bottom, _end));
91 }
92 }
93
94 void ShenandoahHeapRegion::report_illegal_transition(const char *method) {
95 stringStream ss;
96 ss.print("Illegal region state transition from \"%s\", at %s\n ", region_state_to_string(_state), method);
97 print_on(&ss);
98 fatal("%s", ss.freeze());
99 }
100
101 void ShenandoahHeapRegion::make_regular_allocation(ShenandoahAffiliation affiliation) {
102 shenandoah_assert_heaplocked();
103 reset_age();
104 switch (_state) {
105 case _empty_uncommitted:
106 do_commit();
107 case _empty_committed:
108 assert(this->affiliation() == affiliation, "Region affiliation should already be established");
109 set_state(_regular);
110 case _regular:
111 case _pinned:
112 return;
113 default:
114 report_illegal_transition("regular allocation");
115 }
116 }
117
118 // Change affiliation to YOUNG_GENERATION if _state is not _pinned_cset, _regular, or _pinned. This implements
119 // behavior previously performed as a side effect of make_regular_bypass(). This is used by Full GC in non-generational
120 // modes to transition regions from FREE. Note that all non-free regions in single-generational modes are young.
121 void ShenandoahHeapRegion::make_affiliated_maybe() {
122 shenandoah_assert_heaplocked();
123 assert(!ShenandoahHeap::heap()->mode()->is_generational(), "Only call if non-generational");
124 switch (_state) {
125 case _empty_uncommitted:
126 case _empty_committed:
127 case _cset:
128 case _humongous_start:
129 case _humongous_cont:
130 if (affiliation() != YOUNG_GENERATION) {
131 set_affiliation(YOUNG_GENERATION);
132 }
133 return;
134 case _pinned_cset:
135 case _regular:
136 case _pinned:
137 return;
138 default:
139 assert(false, "Unexpected _state in make_affiliated_maybe");
140 }
141 }
142
143 void ShenandoahHeapRegion::make_regular_bypass() {
144 shenandoah_assert_heaplocked();
145 assert (ShenandoahHeap::heap()->is_full_gc_in_progress() || ShenandoahHeap::heap()->is_degenerated_gc_in_progress(),
146 "only for full or degen GC");
147 reset_age();
148 switch (_state) {
149 case _empty_uncommitted:
150 do_commit();
151 case _empty_committed:
152 case _cset:
153 case _humongous_start:
154 case _humongous_cont:
155 set_state(_regular);
156 return;
157 case _pinned_cset:
158 set_state(_pinned);
159 return;
160 case _regular:
161 case _pinned:
162 return;
163 default:
164 report_illegal_transition("regular bypass");
165 }
166 }
167
168 void ShenandoahHeapRegion::make_humongous_start() {
169 shenandoah_assert_heaplocked();
170 reset_age();
171 switch (_state) {
172 case _empty_uncommitted:
173 do_commit();
174 case _empty_committed:
175 set_state(_humongous_start);
176 return;
177 default:
178 report_illegal_transition("humongous start allocation");
179 }
180 }
181
182 void ShenandoahHeapRegion::make_humongous_start_bypass(ShenandoahAffiliation affiliation) {
183 shenandoah_assert_heaplocked();
184 assert (ShenandoahHeap::heap()->is_full_gc_in_progress(), "only for full GC");
185 // Don't bother to account for affiliated regions during Full GC. We recompute totals at end.
186 set_affiliation(affiliation);
187 reset_age();
188 switch (_state) {
189 case _empty_committed:
190 case _regular:
191 case _humongous_start:
192 case _humongous_cont:
193 set_state(_humongous_start);
194 return;
195 default:
196 report_illegal_transition("humongous start bypass");
197 }
198 }
199
200 void ShenandoahHeapRegion::make_humongous_cont() {
201 shenandoah_assert_heaplocked();
202 reset_age();
203 switch (_state) {
204 case _empty_uncommitted:
205 do_commit();
206 case _empty_committed:
207 set_state(_humongous_cont);
208 return;
209 default:
210 report_illegal_transition("humongous continuation allocation");
211 }
212 }
213
214 void ShenandoahHeapRegion::make_humongous_cont_bypass(ShenandoahAffiliation affiliation) {
215 shenandoah_assert_heaplocked();
216 assert (ShenandoahHeap::heap()->is_full_gc_in_progress(), "only for full GC");
217 set_affiliation(affiliation);
218 // Don't bother to account for affiliated regions during Full GC. We recompute totals at end.
219 reset_age();
220 switch (_state) {
221 case _empty_committed:
222 case _regular:
223 case _humongous_start:
224 case _humongous_cont:
225 set_state(_humongous_cont);
226 return;
227 default:
228 report_illegal_transition("humongous continuation bypass");
229 }
230 }
231
232 void ShenandoahHeapRegion::make_pinned() {
233 shenandoah_assert_heaplocked();
234 assert(pin_count() > 0, "Should have pins: " SIZE_FORMAT, pin_count());
235
236 switch (_state) {
237 case _regular:
238 set_state(_pinned);
239 case _pinned_cset:
240 case _pinned:
241 return;
242 case _humongous_start:
243 set_state(_pinned_humongous_start);
244 case _pinned_humongous_start:
245 return;
246 case _cset:
247 _state = _pinned_cset;
248 return;
249 default:
250 report_illegal_transition("pinning");
251 }
252 }
253
254 void ShenandoahHeapRegion::make_unpinned() {
255 shenandoah_assert_heaplocked();
256 assert(pin_count() == 0, "Should not have pins: " SIZE_FORMAT, pin_count());
257
258 switch (_state) {
259 case _pinned:
260 assert(is_affiliated(), "Pinned region should be affiliated");
261 set_state(_regular);
262 return;
263 case _regular:
264 case _humongous_start:
265 return;
266 case _pinned_cset:
267 set_state(_cset);
268 return;
269 case _pinned_humongous_start:
270 set_state(_humongous_start);
271 return;
272 default:
273 report_illegal_transition("unpinning");
274 }
275 }
276
277 void ShenandoahHeapRegion::make_cset() {
278 shenandoah_assert_heaplocked();
279 // Leave age untouched. We need to consult the age when we are deciding whether to promote evacuated objects.
280 switch (_state) {
281 case _regular:
282 set_state(_cset);
283 case _cset:
284 return;
285 default:
286 report_illegal_transition("cset");
287 }
288 }
289
290 void ShenandoahHeapRegion::make_trash() {
291 shenandoah_assert_heaplocked();
292 reset_age();
293 switch (_state) {
294 case _humongous_start:
295 case _humongous_cont:
296 {
297 // Reclaiming humongous regions and reclaim humongous waste. When this region is eventually recycled, we'll reclaim
298 // its used memory. At recycle time, we no longer recognize this as a humongous region.
299 decrement_humongous_waste();
300 }
301 case _cset:
302 // Reclaiming cset regions
303 case _regular:
304 // Immediate region reclaim
305 set_state(_trash);
306 return;
307 default:
308 report_illegal_transition("trashing");
309 }
310 }
311
312 void ShenandoahHeapRegion::make_trash_immediate() {
313 make_trash();
314
315 // On this path, we know there are no marked objects in the region,
316 // tell marking context about it to bypass bitmap resets.
317 assert(ShenandoahHeap::heap()->gc_generation()->is_mark_complete(), "Marking should be complete here.");
318 shenandoah_assert_generations_reconciled();
319 ShenandoahHeap::heap()->marking_context()->reset_top_bitmap(this);
320 }
321
322 void ShenandoahHeapRegion::make_empty() {
323 shenandoah_assert_heaplocked();
324 reset_age();
325 CENSUS_NOISE(clear_youth();)
326 switch (_state) {
327 case _trash:
328 set_state(_empty_committed);
329 _empty_time = os::elapsedTime();
330 return;
331 default:
332 report_illegal_transition("emptying");
333 }
334 }
335
336 void ShenandoahHeapRegion::make_uncommitted() {
337 shenandoah_assert_heaplocked();
338 switch (_state) {
339 case _empty_committed:
340 do_uncommit();
341 set_state(_empty_uncommitted);
342 return;
343 default:
344 report_illegal_transition("uncommiting");
345 }
346 }
347
348 void ShenandoahHeapRegion::make_committed_bypass() {
349 shenandoah_assert_heaplocked();
350 assert (ShenandoahHeap::heap()->is_full_gc_in_progress(), "only for full GC");
351
352 switch (_state) {
353 case _empty_uncommitted:
354 do_commit();
355 set_state(_empty_committed);
356 return;
357 default:
358 report_illegal_transition("commit bypass");
359 }
360 }
361
362 void ShenandoahHeapRegion::reset_alloc_metadata() {
363 _tlab_allocs = 0;
364 _gclab_allocs = 0;
365 _plab_allocs = 0;
366 }
367
368 size_t ShenandoahHeapRegion::get_shared_allocs() const {
369 return used() - (_tlab_allocs + _gclab_allocs + _plab_allocs) * HeapWordSize;
370 }
371
372 size_t ShenandoahHeapRegion::get_tlab_allocs() const {
373 return _tlab_allocs * HeapWordSize;
374 }
375
376 size_t ShenandoahHeapRegion::get_gclab_allocs() const {
377 return _gclab_allocs * HeapWordSize;
378 }
379
380 size_t ShenandoahHeapRegion::get_plab_allocs() const {
381 return _plab_allocs * HeapWordSize;
382 }
383
384 void ShenandoahHeapRegion::set_live_data(size_t s) {
385 assert(Thread::current()->is_VM_thread(), "by VM thread");
386 _live_data = (s >> LogHeapWordSize);
387 }
388
389 void ShenandoahHeapRegion::print_on(outputStream* st) const {
390 st->print("|");
391 st->print(SIZE_FORMAT_W(5), this->_index);
392
393 switch (_state) {
394 case _empty_uncommitted:
395 st->print("|EU ");
396 break;
397 case _empty_committed:
398 st->print("|EC ");
399 break;
400 case _regular:
401 st->print("|R ");
402 break;
403 case _humongous_start:
404 st->print("|H ");
405 break;
406 case _pinned_humongous_start:
407 st->print("|HP ");
408 break;
409 case _humongous_cont:
410 st->print("|HC ");
411 break;
412 case _cset:
413 st->print("|CS ");
414 break;
415 case _trash:
416 st->print("|TR ");
417 break;
418 case _pinned:
419 st->print("|P ");
420 break;
421 case _pinned_cset:
422 st->print("|CSP");
423 break;
424 default:
425 ShouldNotReachHere();
426 }
427
428 st->print("|%s", shenandoah_affiliation_code(affiliation()));
429
430 #define SHR_PTR_FORMAT "%12" PRIxPTR
431
432 st->print("|BTE " SHR_PTR_FORMAT ", " SHR_PTR_FORMAT ", " SHR_PTR_FORMAT,
433 p2i(bottom()), p2i(top()), p2i(end()));
434 st->print("|TAMS " SHR_PTR_FORMAT,
435 p2i(ShenandoahHeap::heap()->marking_context()->top_at_mark_start(const_cast<ShenandoahHeapRegion*>(this))));
436 st->print("|UWM " SHR_PTR_FORMAT,
437 p2i(_update_watermark));
438 st->print("|U " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(used()), proper_unit_for_byte_size(used()));
439 st->print("|T " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_tlab_allocs()), proper_unit_for_byte_size(get_tlab_allocs()));
440 st->print("|G " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_gclab_allocs()), proper_unit_for_byte_size(get_gclab_allocs()));
441 if (ShenandoahHeap::heap()->mode()->is_generational()) {
442 st->print("|P " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_plab_allocs()), proper_unit_for_byte_size(get_plab_allocs()));
443 }
444 st->print("|S " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_shared_allocs()), proper_unit_for_byte_size(get_shared_allocs()));
445 st->print("|L " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_live_data_bytes()), proper_unit_for_byte_size(get_live_data_bytes()));
446 st->print("|CP " SIZE_FORMAT_W(3), pin_count());
447 st->cr();
448
449 #undef SHR_PTR_FORMAT
450 }
451
452 // oop_iterate without closure, return true if completed without cancellation
453 bool ShenandoahHeapRegion::oop_coalesce_and_fill(bool cancellable) {
454
455 assert(!is_humongous(), "No need to fill or coalesce humongous regions");
456 if (!is_active()) {
457 end_preemptible_coalesce_and_fill();
458 return true;
459 }
460
461 ShenandoahGenerationalHeap* heap = ShenandoahGenerationalHeap::heap();
462 ShenandoahMarkingContext* marking_context = heap->marking_context();
463
464 // Expect marking to be completed before these threads invoke this service.
465 assert(heap->gc_generation()->is_mark_complete(), "sanity");
466 shenandoah_assert_generations_reconciled();
467
468 // All objects above TAMS are considered live even though their mark bits will not be set. Note that young-
469 // gen evacuations that interrupt a long-running old-gen concurrent mark may promote objects into old-gen
470 // while the old-gen concurrent marking is ongoing. These newly promoted objects will reside above TAMS
471 // and will be treated as live during the current old-gen marking pass, even though they will not be
472 // explicitly marked.
473 HeapWord* t = marking_context->top_at_mark_start(this);
474
475 // Resume coalesce and fill from this address
476 HeapWord* obj_addr = resume_coalesce_and_fill();
477
478 while (obj_addr < t) {
479 oop obj = cast_to_oop(obj_addr);
480 if (marking_context->is_marked(obj)) {
481 assert(obj->klass() != nullptr, "klass should not be nullptr");
482 obj_addr += obj->size();
483 } else {
484 // Object is not marked. Coalesce and fill dead object with dead neighbors.
485 HeapWord* next_marked_obj = marking_context->get_next_marked_addr(obj_addr, t);
486 assert(next_marked_obj <= t, "next marked object cannot exceed top");
487 size_t fill_size = next_marked_obj - obj_addr;
488 assert(fill_size >= ShenandoahHeap::min_fill_size(), "previously allocated object known to be larger than min_size");
489 ShenandoahHeap::fill_with_object(obj_addr, fill_size);
490 heap->old_generation()->card_scan()->coalesce_objects(obj_addr, fill_size);
491 obj_addr = next_marked_obj;
492 }
493 if (cancellable && heap->cancelled_gc()) {
494 suspend_coalesce_and_fill(obj_addr);
495 return false;
496 }
497 }
498 // Mark that this region has been coalesced and filled
499 end_preemptible_coalesce_and_fill();
500 return true;
501 }
502
503 size_t get_card_count(size_t words) {
504 assert(words % CardTable::card_size_in_words() == 0, "Humongous iteration must span whole number of cards");
505 assert(CardTable::card_size_in_words() * (words / CardTable::card_size_in_words()) == words,
506 "slice must be integral number of cards");
507 return words / CardTable::card_size_in_words();
508 }
509
510 void ShenandoahHeapRegion::oop_iterate_humongous_slice_dirty(OopIterateClosure* blk,
511 HeapWord* start, size_t words, bool write_table) const {
512 assert(is_humongous(), "only humongous region here");
513
514 ShenandoahHeapRegion* r = humongous_start_region();
515 oop obj = cast_to_oop(r->bottom());
516 size_t num_cards = get_card_count(words);
517
518 ShenandoahGenerationalHeap* heap = ShenandoahGenerationalHeap::heap();
519 ShenandoahScanRemembered* scanner = heap->old_generation()->card_scan();
520 size_t card_index = scanner->card_index_for_addr(start);
521 if (write_table) {
522 while (num_cards-- > 0) {
523 if (scanner->is_write_card_dirty(card_index++)) {
524 obj->oop_iterate(blk, MemRegion(start, start + CardTable::card_size_in_words()));
525 }
526 start += CardTable::card_size_in_words();
527 }
528 } else {
529 while (num_cards-- > 0) {
530 if (scanner->is_card_dirty(card_index++)) {
531 obj->oop_iterate(blk, MemRegion(start, start + CardTable::card_size_in_words()));
532 }
533 start += CardTable::card_size_in_words();
534 }
535 }
536 }
537
538 void ShenandoahHeapRegion::oop_iterate_humongous_slice_all(OopIterateClosure* cl, HeapWord* start, size_t words) const {
539 assert(is_humongous(), "only humongous region here");
540
541 ShenandoahHeapRegion* r = humongous_start_region();
542 oop obj = cast_to_oop(r->bottom());
543
544 // Scan all data, regardless of whether cards are dirty
545 obj->oop_iterate(cl, MemRegion(start, start + words));
546 }
547
548 ShenandoahHeapRegion* ShenandoahHeapRegion::humongous_start_region() const {
549 ShenandoahHeap* heap = ShenandoahHeap::heap();
550 assert(is_humongous(), "Must be a part of the humongous region");
551 size_t i = index();
552 ShenandoahHeapRegion* r = const_cast<ShenandoahHeapRegion*>(this);
553 while (!r->is_humongous_start()) {
554 assert(i > 0, "Sanity");
555 i--;
556 r = heap->get_region(i);
557 assert(r->is_humongous(), "Must be a part of the humongous region");
558 }
559 assert(r->is_humongous_start(), "Must be");
560 return r;
561 }
562
563 void ShenandoahHeapRegion::recycle() {
564 shenandoah_assert_heaplocked();
565 ShenandoahHeap* heap = ShenandoahHeap::heap();
566 ShenandoahGeneration* generation = heap->generation_for(affiliation());
567
568 heap->decrease_used(generation, used());
569 generation->decrement_affiliated_region_count();
570
571 set_top(bottom());
572 clear_live_data();
573 reset_alloc_metadata();
574
575 heap->marking_context()->reset_top_at_mark_start(this);
576
577 set_update_watermark(bottom());
578
579 make_empty();
580
581 set_affiliation(FREE);
582 if (ZapUnusedHeapArea) {
583 SpaceMangler::mangle_region(MemRegion(bottom(), end()));
584 }
585 }
586
587 HeapWord* ShenandoahHeapRegion::block_start(const void* p) const {
588 assert(MemRegion(bottom(), end()).contains(p),
589 "p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
590 p2i(p), p2i(bottom()), p2i(end()));
591 if (p >= top()) {
592 return top();
593 } else {
594 HeapWord* last = bottom();
595 HeapWord* cur = last;
596 while (cur <= p) {
597 last = cur;
598 cur += cast_to_oop(cur)->size();
599 }
600 shenandoah_assert_correct(nullptr, cast_to_oop(last));
601 return last;
602 }
603 }
604
605 size_t ShenandoahHeapRegion::block_size(const HeapWord* p) const {
606 assert(MemRegion(bottom(), end()).contains(p),
607 "p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
608 p2i(p), p2i(bottom()), p2i(end()));
609 if (p < top()) {
610 return cast_to_oop(p)->size();
611 } else {
612 assert(p == top(), "just checking");
613 return pointer_delta(end(), (HeapWord*) p);
614 }
615 }
616
617 size_t ShenandoahHeapRegion::setup_sizes(size_t max_heap_size) {
618 // Absolute minimums we should not ever break.
619 static const size_t MIN_REGION_SIZE = 256*K;
620
621 if (FLAG_IS_DEFAULT(ShenandoahMinRegionSize)) {
622 FLAG_SET_DEFAULT(ShenandoahMinRegionSize, MIN_REGION_SIZE);
623 }
624
625 // Generational Shenandoah needs this alignment for card tables.
626 if (strcmp(ShenandoahGCMode, "generational") == 0) {
627 max_heap_size = align_up(max_heap_size , CardTable::ct_max_alignment_constraint());
628 }
629
630 size_t region_size;
631 if (FLAG_IS_DEFAULT(ShenandoahRegionSize)) {
632 if (ShenandoahMinRegionSize > max_heap_size / MIN_NUM_REGIONS) {
633 err_msg message("Max heap size (" SIZE_FORMAT "%s) is too low to afford the minimum number "
634 "of regions (" SIZE_FORMAT ") of minimum region size (" SIZE_FORMAT "%s).",
635 byte_size_in_proper_unit(max_heap_size), proper_unit_for_byte_size(max_heap_size),
636 MIN_NUM_REGIONS,
637 byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize));
638 vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
639 }
640 if (ShenandoahMinRegionSize < MIN_REGION_SIZE) {
641 err_msg message("" SIZE_FORMAT "%s should not be lower than minimum region size (" SIZE_FORMAT "%s).",
642 byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
643 byte_size_in_proper_unit(MIN_REGION_SIZE), proper_unit_for_byte_size(MIN_REGION_SIZE));
644 vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
645 }
646 if (ShenandoahMinRegionSize < MinTLABSize) {
647 err_msg message("" SIZE_FORMAT "%s should not be lower than TLAB size size (" SIZE_FORMAT "%s).",
648 byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
649 byte_size_in_proper_unit(MinTLABSize), proper_unit_for_byte_size(MinTLABSize));
650 vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
651 }
652 if (ShenandoahMaxRegionSize < MIN_REGION_SIZE) {
653 err_msg message("" SIZE_FORMAT "%s should not be lower than min region size (" SIZE_FORMAT "%s).",
654 byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize),
655 byte_size_in_proper_unit(MIN_REGION_SIZE), proper_unit_for_byte_size(MIN_REGION_SIZE));
656 vm_exit_during_initialization("Invalid -XX:ShenandoahMaxRegionSize option", message);
657 }
658 if (ShenandoahMinRegionSize > ShenandoahMaxRegionSize) {
659 err_msg message("Minimum (" SIZE_FORMAT "%s) should be larger than maximum (" SIZE_FORMAT "%s).",
660 byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
661 byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize));
662 vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize or -XX:ShenandoahMaxRegionSize", message);
663 }
664
665 // We rapidly expand to max_heap_size in most scenarios, so that is the measure
666 // for usual heap sizes. Do not depend on initial_heap_size here.
667 region_size = max_heap_size / ShenandoahTargetNumRegions;
668
669 // Now make sure that we don't go over or under our limits.
670 region_size = MAX2(ShenandoahMinRegionSize, region_size);
671 region_size = MIN2(ShenandoahMaxRegionSize, region_size);
672
673 } else {
674 if (ShenandoahRegionSize > max_heap_size / MIN_NUM_REGIONS) {
675 err_msg message("Max heap size (" SIZE_FORMAT "%s) is too low to afford the minimum number "
676 "of regions (" SIZE_FORMAT ") of requested size (" SIZE_FORMAT "%s).",
677 byte_size_in_proper_unit(max_heap_size), proper_unit_for_byte_size(max_heap_size),
678 MIN_NUM_REGIONS,
679 byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize));
680 vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
681 }
682 if (ShenandoahRegionSize < ShenandoahMinRegionSize) {
683 err_msg message("Heap region size (" SIZE_FORMAT "%s) should be larger than min region size (" SIZE_FORMAT "%s).",
684 byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize),
685 byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize));
686 vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
687 }
688 if (ShenandoahRegionSize > ShenandoahMaxRegionSize) {
689 err_msg message("Heap region size (" SIZE_FORMAT "%s) should be lower than max region size (" SIZE_FORMAT "%s).",
690 byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize),
691 byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize));
692 vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
693 }
694 region_size = ShenandoahRegionSize;
695 }
696
697 // Make sure region size and heap size are page aligned.
698 // If large pages are used, we ensure that region size is aligned to large page size if
699 // heap size is large enough to accommodate minimal number of regions. Otherwise, we align
700 // region size to regular page size.
701
702 // Figure out page size to use, and aligns up heap to page size
703 size_t page_size = os::vm_page_size();
704 if (UseLargePages) {
705 size_t large_page_size = os::large_page_size();
706 max_heap_size = align_up(max_heap_size, large_page_size);
707 if ((max_heap_size / align_up(region_size, large_page_size)) >= MIN_NUM_REGIONS) {
708 page_size = large_page_size;
709 } else {
710 // Should have been checked during argument initialization
711 assert(!ShenandoahUncommit, "Uncommit requires region size aligns to large page size");
712 }
713 } else {
714 max_heap_size = align_up(max_heap_size, page_size);
715 }
716
717 // Align region size to page size
718 region_size = align_up(region_size, page_size);
719
720 int region_size_log = log2i(region_size);
721 // Recalculate the region size to make sure it's a power of
722 // 2. This means that region_size is the largest power of 2 that's
723 // <= what we've calculated so far.
724 region_size = size_t(1) << region_size_log;
725
726 // Now, set up the globals.
727 guarantee(RegionSizeBytesShift == 0, "we should only set it once");
728 RegionSizeBytesShift = (size_t)region_size_log;
729
730 guarantee(RegionSizeWordsShift == 0, "we should only set it once");
731 RegionSizeWordsShift = RegionSizeBytesShift - LogHeapWordSize;
732
733 guarantee(RegionSizeBytes == 0, "we should only set it once");
734 RegionSizeBytes = region_size;
735 RegionSizeWords = RegionSizeBytes >> LogHeapWordSize;
736 assert (RegionSizeWords*HeapWordSize == RegionSizeBytes, "sanity");
737
738 guarantee(RegionSizeWordsMask == 0, "we should only set it once");
739 RegionSizeWordsMask = RegionSizeWords - 1;
740
741 guarantee(RegionSizeBytesMask == 0, "we should only set it once");
742 RegionSizeBytesMask = RegionSizeBytes - 1;
743
744 guarantee(RegionCount == 0, "we should only set it once");
745 RegionCount = align_up(max_heap_size, RegionSizeBytes) / RegionSizeBytes;
746 guarantee(RegionCount >= MIN_NUM_REGIONS, "Should have at least minimum regions");
747
748 guarantee(MaxTLABSizeWords == 0, "we should only set it once");
749 MaxTLABSizeWords = align_down(RegionSizeWords, MinObjAlignment);
750
751 guarantee(MaxTLABSizeBytes == 0, "we should only set it once");
752 MaxTLABSizeBytes = MaxTLABSizeWords * HeapWordSize;
753 assert (MaxTLABSizeBytes > MinTLABSize, "should be larger");
754
755 return max_heap_size;
756 }
757
758 void ShenandoahHeapRegion::do_commit() {
759 ShenandoahHeap* heap = ShenandoahHeap::heap();
760 if (!heap->is_heap_region_special() && !os::commit_memory((char *) bottom(), RegionSizeBytes, false)) {
761 report_java_out_of_memory("Unable to commit region");
762 }
763 if (!heap->commit_bitmap_slice(this)) {
764 report_java_out_of_memory("Unable to commit bitmaps for region");
765 }
766 if (AlwaysPreTouch) {
767 os::pretouch_memory(bottom(), end(), heap->pretouch_heap_page_size());
768 }
769 heap->increase_committed(ShenandoahHeapRegion::region_size_bytes());
770 }
771
772 void ShenandoahHeapRegion::do_uncommit() {
773 ShenandoahHeap* heap = ShenandoahHeap::heap();
774 if (!heap->is_heap_region_special() && !os::uncommit_memory((char *) bottom(), RegionSizeBytes)) {
775 report_java_out_of_memory("Unable to uncommit region");
776 }
777 if (!heap->uncommit_bitmap_slice(this)) {
778 report_java_out_of_memory("Unable to uncommit bitmaps for region");
779 }
780 heap->decrease_committed(ShenandoahHeapRegion::region_size_bytes());
781 }
782
783 void ShenandoahHeapRegion::set_state(RegionState to) {
784 EventShenandoahHeapRegionStateChange evt;
785 if (evt.should_commit()){
786 evt.set_index((unsigned) index());
787 evt.set_start((uintptr_t)bottom());
788 evt.set_used(used());
789 evt.set_from(_state);
790 evt.set_to(to);
791 evt.commit();
792 }
793 _state = to;
794 }
795
796 void ShenandoahHeapRegion::record_pin() {
797 Atomic::add(&_critical_pins, (size_t)1);
798 }
799
800 void ShenandoahHeapRegion::record_unpin() {
801 assert(pin_count() > 0, "Region " SIZE_FORMAT " should have non-zero pins", index());
802 Atomic::sub(&_critical_pins, (size_t)1);
803 }
804
805 size_t ShenandoahHeapRegion::pin_count() const {
806 return Atomic::load(&_critical_pins);
807 }
808
809 void ShenandoahHeapRegion::set_affiliation(ShenandoahAffiliation new_affiliation) {
810 ShenandoahHeap* heap = ShenandoahHeap::heap();
811
812 ShenandoahAffiliation region_affiliation = heap->region_affiliation(this);
813 {
814 ShenandoahMarkingContext* const ctx = heap->complete_marking_context();
815 log_debug(gc)("Setting affiliation of Region " SIZE_FORMAT " from %s to %s, top: " PTR_FORMAT ", TAMS: " PTR_FORMAT
816 ", watermark: " PTR_FORMAT ", top_bitmap: " PTR_FORMAT,
817 index(), shenandoah_affiliation_name(region_affiliation), shenandoah_affiliation_name(new_affiliation),
818 p2i(top()), p2i(ctx->top_at_mark_start(this)), p2i(_update_watermark), p2i(ctx->top_bitmap(this)));
819 }
820
821 #ifdef ASSERT
822 {
823 // During full gc, heap->complete_marking_context() is not valid, may equal nullptr.
824 ShenandoahMarkingContext* const ctx = heap->complete_marking_context();
825 size_t idx = this->index();
826 HeapWord* top_bitmap = ctx->top_bitmap(this);
827
828 assert(ctx->is_bitmap_clear_range(top_bitmap, _end),
829 "Region " SIZE_FORMAT ", bitmap should be clear between top_bitmap: " PTR_FORMAT " and end: " PTR_FORMAT, idx,
830 p2i(top_bitmap), p2i(_end));
831 }
832 #endif
833
834 if (region_affiliation == new_affiliation) {
835 return;
836 }
837
838 if (!heap->mode()->is_generational()) {
839 log_trace(gc)("Changing affiliation of region %zu from %s to %s",
840 index(), affiliation_name(), shenandoah_affiliation_name(new_affiliation));
841 heap->set_affiliation(this, new_affiliation);
842 return;
843 }
844
845 switch (new_affiliation) {
846 case FREE:
847 assert(!has_live(), "Free region should not have live data");
848 break;
849 case YOUNG_GENERATION:
850 reset_age();
851 break;
852 case OLD_GENERATION:
853 break;
854 default:
855 ShouldNotReachHere();
856 return;
857 }
858 heap->set_affiliation(this, new_affiliation);
859 }
860
861 void ShenandoahHeapRegion::decrement_humongous_waste() const {
862 assert(is_humongous(), "Should only use this for humongous regions");
863 size_t waste_bytes = free();
864 if (waste_bytes > 0) {
865 ShenandoahHeap* heap = ShenandoahHeap::heap();
866 ShenandoahGeneration* generation = heap->generation_for(affiliation());
867 heap->decrease_humongous_waste(generation, waste_bytes);
868 }
869 }