1 /*
2 * Copyright (c) 2001, 2019, 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 "code/nmethod.hpp"
27 #include "gc/g1/g1BlockOffsetTable.inline.hpp"
28 #include "gc/g1/g1CollectedHeap.inline.hpp"
29 #include "gc/g1/g1CollectionSet.hpp"
30 #include "gc/g1/g1HeapRegionTraceType.hpp"
31 #include "gc/g1/g1OopClosures.inline.hpp"
32 #include "gc/g1/heapRegion.inline.hpp"
33 #include "gc/g1/heapRegionBounds.inline.hpp"
34 #include "gc/g1/heapRegionManager.inline.hpp"
35 #include "gc/g1/heapRegionRemSet.hpp"
36 #include "gc/g1/heapRegionTracer.hpp"
37 #include "gc/shared/genOopClosures.inline.hpp"
38 #include "logging/log.hpp"
39 #include "logging/logStream.hpp"
40 #include "memory/iterator.inline.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "oops/access.inline.hpp"
43 #include "oops/compressedOops.inline.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "runtime/atomic.hpp"
46 #include "runtime/orderAccess.hpp"
47
48 int HeapRegion::LogOfHRGrainBytes = 0;
49 int HeapRegion::LogOfHRGrainWords = 0;
50 int HeapRegion::LogCardsPerRegion = 0;
51 size_t HeapRegion::GrainBytes = 0;
52 size_t HeapRegion::GrainWords = 0;
53 size_t HeapRegion::CardsPerRegion = 0;
54
55 size_t HeapRegion::max_region_size() {
56 return HeapRegionBounds::max_size();
57 }
58
59 size_t HeapRegion::min_region_size_in_words() {
60 return HeapRegionBounds::min_size() >> LogHeapWordSize;
61 }
62
63 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
64 size_t region_size = G1HeapRegionSize;
65 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
66 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2;
67 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(),
68 HeapRegionBounds::min_size());
69 }
70
71 int region_size_log = log2_long((jlong) region_size);
72 // Recalculate the region size to make sure it's a power of
73 // 2. This means that region_size is the largest power of 2 that's
74 // <= what we've calculated so far.
75 region_size = ((size_t)1 << region_size_log);
76
77 // Now make sure that we don't go over or under our limits.
78 if (region_size < HeapRegionBounds::min_size()) {
79 region_size = HeapRegionBounds::min_size();
80 } else if (region_size > HeapRegionBounds::max_size()) {
81 region_size = HeapRegionBounds::max_size();
82 }
83
84 // And recalculate the log.
85 region_size_log = log2_long((jlong) region_size);
86
87 // Now, set up the globals.
88 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
89 LogOfHRGrainBytes = region_size_log;
90
91 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
92 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
93
94 guarantee(GrainBytes == 0, "we should only set it once");
95 // The cast to int is safe, given that we've bounded region_size by
96 // MIN_REGION_SIZE and MAX_REGION_SIZE.
97 GrainBytes = region_size;
98 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M);
99
100 guarantee(GrainWords == 0, "we should only set it once");
101 GrainWords = GrainBytes >> LogHeapWordSize;
102 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
103
104 guarantee(CardsPerRegion == 0, "we should only set it once");
105 CardsPerRegion = GrainBytes >> G1CardTable::card_shift;
106
107 LogCardsPerRegion = log2_long((jlong) CardsPerRegion);
108
109 if (G1HeapRegionSize != GrainBytes) {
110 FLAG_SET_ERGO(G1HeapRegionSize, GrainBytes);
111 }
112 }
113
114 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) {
115 assert(_humongous_start_region == NULL,
116 "we should have already filtered out humongous regions");
117 assert(!in_collection_set(),
118 "Should not clear heap region %u in the collection set", hrm_index());
119
120 clear_young_index_in_cset();
121 clear_index_in_opt_cset();
122 uninstall_surv_rate_group();
123 set_free();
124 reset_pre_dummy_top();
125
126 if (!keep_remset) {
127 if (locked) {
128 rem_set()->clear_locked();
129 } else {
130 rem_set()->clear();
131 }
132 }
133
134 zero_marked_bytes();
135
136 init_top_at_mark_start();
137 if (clear_space) clear(SpaceDecorator::Mangle);
138 }
139
140 void HeapRegion::clear_cardtable() {
141 G1CardTable* ct = G1CollectedHeap::heap()->card_table();
142 ct->clear(MemRegion(bottom(), end()));
143 }
144
145 void HeapRegion::calc_gc_efficiency() {
146 // GC efficiency is the ratio of how much space would be
147 // reclaimed over how long we predict it would take to reclaim it.
148 G1CollectedHeap* g1h = G1CollectedHeap::heap();
149 G1Policy* policy = g1h->policy();
150
151 // Retrieve a prediction of the elapsed time for this region for
152 // a mixed gc because the region will only be evacuated during a
153 // mixed gc.
154 double region_elapsed_time_ms =
155 policy->predict_region_elapsed_time_ms(this, false /* for_young_gc */);
156 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
157 }
158
159 void HeapRegion::set_free() {
160 report_region_type_change(G1HeapRegionTraceType::Free);
161 _type.set_free();
162 }
163
164 void HeapRegion::set_eden() {
165 report_region_type_change(G1HeapRegionTraceType::Eden);
166 _type.set_eden();
167 }
168
169 void HeapRegion::set_eden_pre_gc() {
170 report_region_type_change(G1HeapRegionTraceType::Eden);
171 _type.set_eden_pre_gc();
172 }
173
174 void HeapRegion::set_survivor() {
175 report_region_type_change(G1HeapRegionTraceType::Survivor);
176 _type.set_survivor();
177 }
178
179 void HeapRegion::move_to_old() {
180 if (_type.relabel_as_old()) {
181 report_region_type_change(G1HeapRegionTraceType::Old);
182 }
183 }
184
185 void HeapRegion::set_old() {
186 report_region_type_change(G1HeapRegionTraceType::Old);
187 _type.set_old();
188 }
189
190 void HeapRegion::set_open_archive() {
191 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
192 _type.set_open_archive();
193 }
194
195 void HeapRegion::set_closed_archive() {
196 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
197 _type.set_closed_archive();
198 }
199
200 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
201 assert(!is_humongous(), "sanity / pre-condition");
202 assert(top() == bottom(), "should be empty");
203
204 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
205 _type.set_starts_humongous();
206 _humongous_start_region = this;
207
208 _bot_part.set_for_starts_humongous(obj_top, fill_size);
209 }
210
211 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
212 assert(!is_humongous(), "sanity / pre-condition");
213 assert(top() == bottom(), "should be empty");
214 assert(first_hr->is_starts_humongous(), "pre-condition");
215
216 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
217 _type.set_continues_humongous();
218 _humongous_start_region = first_hr;
219
220 _bot_part.set_object_can_span(true);
221 }
222
223 void HeapRegion::clear_humongous() {
224 assert(is_humongous(), "pre-condition");
225
226 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
227 _humongous_start_region = NULL;
228
229 _bot_part.set_object_can_span(false);
230 }
231
232 HeapRegion::HeapRegion(uint hrm_index,
233 G1BlockOffsetTable* bot,
234 MemRegion mr) :
235 _bottom(NULL),
236 _end(NULL),
237 _top(NULL),
238 _compaction_top(NULL),
239 _bot_part(bot, this),
240 _par_alloc_lock(Mutex::leaf, "HeapRegion par alloc lock", true),
241 _pre_dummy_top(NULL),
242 _rem_set(NULL),
243 _hrm_index(hrm_index),
244 _type(),
245 _humongous_start_region(NULL),
246 _evacuation_failed(false),
247 _next(NULL), _prev(NULL),
248 #ifdef ASSERT
249 _containing_set(NULL),
250 #endif
251 _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0),
252 _index_in_opt_cset(InvalidCSetIndex), _young_index_in_cset(-1),
253 _surv_rate_group(NULL), _age_index(-1),
254 _prev_top_at_mark_start(NULL), _next_top_at_mark_start(NULL),
255 _recorded_rs_length(0), _predicted_elapsed_time_ms(0)
256 {
257 _rem_set = new HeapRegionRemSet(bot, this);
258
259 initialize(mr);
260 }
261
262 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
263 assert(_rem_set->is_empty(), "Remembered set must be empty");
264
265 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
266 "invalid space boundaries");
267
268 set_bottom(mr.start());
269 set_end(mr.end());
270 if (clear_space) {
271 clear(mangle_space);
272 }
273
274 set_top(bottom());
275 set_compaction_top(bottom());
276 reset_bot();
277
278 hr_clear(false /*par*/, false /*clear_space*/);
279 }
280
281 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
282 HeapRegionTracer::send_region_type_change(_hrm_index,
283 get_trace_type(),
284 to,
285 (uintptr_t)bottom(),
286 used());
287 }
288
289 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
290 bool during_conc_mark) {
291 // We always recreate the prev marking info and we'll explicitly
292 // mark all objects we find to be self-forwarded on the prev
293 // bitmap. So all objects need to be below PTAMS.
294 _prev_marked_bytes = 0;
295
296 if (during_initial_mark) {
297 // During initial-mark, we'll also explicitly mark all objects
298 // we find to be self-forwarded on the next bitmap. So all
299 // objects need to be below NTAMS.
300 _next_top_at_mark_start = top();
301 _next_marked_bytes = 0;
302 } else if (during_conc_mark) {
303 // During concurrent mark, all objects in the CSet (including
304 // the ones we find to be self-forwarded) are implicitly live.
305 // So all objects need to be above NTAMS.
306 _next_top_at_mark_start = bottom();
307 _next_marked_bytes = 0;
308 }
309 }
310
311 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
312 assert(marked_bytes <= used(),
313 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
314 _prev_top_at_mark_start = top();
315 _prev_marked_bytes = marked_bytes;
316 }
317
318 // Code roots support
319
320 void HeapRegion::add_strong_code_root(nmethod* nm) {
321 HeapRegionRemSet* hrrs = rem_set();
322 hrrs->add_strong_code_root(nm);
323 }
324
325 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
326 assert_locked_or_safepoint(CodeCache_lock);
327 HeapRegionRemSet* hrrs = rem_set();
328 hrrs->add_strong_code_root_locked(nm);
329 }
330
331 void HeapRegion::remove_strong_code_root(nmethod* nm) {
332 HeapRegionRemSet* hrrs = rem_set();
333 hrrs->remove_strong_code_root(nm);
334 }
335
336 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
337 HeapRegionRemSet* hrrs = rem_set();
338 hrrs->strong_code_roots_do(blk);
339 }
340
341 class VerifyStrongCodeRootOopClosure: public OopClosure {
342 const HeapRegion* _hr;
343 bool _failures;
344 bool _has_oops_in_region;
345
346 template <class T> void do_oop_work(T* p) {
347 T heap_oop = RawAccess<>::oop_load(p);
348 if (!CompressedOops::is_null(heap_oop)) {
349 oop obj = CompressedOops::decode_not_null(heap_oop);
350
351 // Note: not all the oops embedded in the nmethod are in the
352 // current region. We only look at those which are.
353 if (_hr->is_in(obj)) {
354 // Object is in the region. Check that its less than top
355 if (_hr->top() <= (HeapWord*)obj) {
356 // Object is above top
357 log_error(gc, verify)("Object " PTR_FORMAT " in region " HR_FORMAT " is above top ",
358 p2i(obj), HR_FORMAT_PARAMS(_hr));
359 _failures = true;
360 return;
361 }
362 // Nmethod has at least one oop in the current region
363 _has_oops_in_region = true;
364 }
365 }
366 }
367
368 public:
369 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
370 _hr(hr), _failures(false), _has_oops_in_region(false) {}
371
372 void do_oop(narrowOop* p) { do_oop_work(p); }
373 void do_oop(oop* p) { do_oop_work(p); }
374
375 bool failures() { return _failures; }
376 bool has_oops_in_region() { return _has_oops_in_region; }
377 };
378
379 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
380 const HeapRegion* _hr;
381 bool _failures;
382 public:
383 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
384 _hr(hr), _failures(false) {}
385
386 void do_code_blob(CodeBlob* cb) {
387 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
388 if (nm != NULL) {
389 // Verify that the nemthod is live
390 if (!nm->is_alive()) {
391 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
392 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
393 _failures = true;
394 } else {
395 VerifyStrongCodeRootOopClosure oop_cl(_hr);
396 nm->oops_do(&oop_cl);
397 if (!oop_cl.has_oops_in_region()) {
398 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
399 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
400 _failures = true;
401 } else if (oop_cl.failures()) {
402 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
403 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
404 _failures = true;
405 }
406 }
407 }
408 }
409
410 bool failures() { return _failures; }
411 };
412
413 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
414 if (!G1VerifyHeapRegionCodeRoots) {
415 // We're not verifying code roots.
416 return;
417 }
418 if (vo == VerifyOption_G1UseFullMarking) {
419 // Marking verification during a full GC is performed after class
420 // unloading, code cache unloading, etc so the strong code roots
421 // attached to each heap region are in an inconsistent state. They won't
422 // be consistent until the strong code roots are rebuilt after the
423 // actual GC. Skip verifying the strong code roots in this particular
424 // time.
425 assert(VerifyDuringGC, "only way to get here");
426 return;
427 }
428
429 HeapRegionRemSet* hrrs = rem_set();
430 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
431
432 // if this region is empty then there should be no entries
433 // on its strong code root list
434 if (is_empty()) {
435 if (strong_code_roots_length > 0) {
436 log_error(gc, verify)("region " HR_FORMAT " is empty but has " SIZE_FORMAT " code root entries",
437 HR_FORMAT_PARAMS(this), strong_code_roots_length);
438 *failures = true;
439 }
440 return;
441 }
442
443 if (is_continues_humongous()) {
444 if (strong_code_roots_length > 0) {
445 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
446 HR_FORMAT_PARAMS(this), strong_code_roots_length);
447 *failures = true;
448 }
449 return;
450 }
451
452 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
453 strong_code_roots_do(&cb_cl);
454
455 if (cb_cl.failures()) {
456 *failures = true;
457 }
458 }
459
460 void HeapRegion::print() const { print_on(tty); }
461
462 void HeapRegion::print_on(outputStream* st) const {
463 st->print("|%4u", this->_hrm_index);
464 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
465 p2i(bottom()), p2i(top()), p2i(end()));
466 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
467 st->print("|%2s", get_short_type_str());
468 if (in_collection_set()) {
469 st->print("|CS");
470 } else {
471 st->print("| ");
472 }
473 st->print_cr("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ",
474 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str());
475 }
476
477 class G1VerificationClosure : public BasicOopIterateClosure {
478 protected:
479 G1CollectedHeap* _g1h;
480 G1CardTable *_ct;
481 oop _containing_obj;
482 bool _failures;
483 int _n_failures;
484 VerifyOption _vo;
485 public:
486 // _vo == UsePrevMarking -> use "prev" marking information,
487 // _vo == UseNextMarking -> use "next" marking information,
488 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
489 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
490 _g1h(g1h), _ct(g1h->card_table()),
491 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
492 }
493
494 void set_containing_obj(oop obj) {
495 _containing_obj = obj;
496 }
497
498 bool failures() { return _failures; }
499 int n_failures() { return _n_failures; }
500
501 void print_object(outputStream* out, oop obj) {
502 #ifdef PRODUCT
503 Klass* k = obj->klass();
504 const char* class_name = k->external_name();
505 out->print_cr("class name %s", class_name);
506 #else // PRODUCT
507 obj->print_on(out);
508 #endif // PRODUCT
509 }
510
511 // This closure provides its own oop verification code.
512 debug_only(virtual bool should_verify_oops() { return false; })
513 };
514
515 class VerifyLiveClosure : public G1VerificationClosure {
516 public:
517 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
518 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
519 virtual void do_oop(oop* p) { do_oop_work(p); }
520
521 template <class T>
522 void do_oop_work(T* p) {
523 assert(_containing_obj != NULL, "Precondition");
524 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
525 "Precondition");
526 verify_liveness(p);
527 }
528
529 template <class T>
530 void verify_liveness(T* p) {
531 T heap_oop = RawAccess<>::oop_load(p);
532 Log(gc, verify) log;
533 if (!CompressedOops::is_null(heap_oop)) {
534 oop obj = CompressedOops::decode_not_null(heap_oop);
535 bool failed = false;
536 if (!_g1h->is_in(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
537 MutexLocker x(ParGCRareEvent_lock,
538 Mutex::_no_safepoint_check_flag);
539
540 if (!_failures) {
541 log.error("----------");
542 }
543 ResourceMark rm;
544 if (!_g1h->is_in(obj)) {
545 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
546 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
547 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
548 LogStream ls(log.error());
549 print_object(&ls, _containing_obj);
550 HeapRegion* const to = _g1h->heap_region_containing(obj);
551 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
552 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
553 } else {
554 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
555 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
556 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
557 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
558 LogStream ls(log.error());
559 print_object(&ls, _containing_obj);
560 log.error("points to dead obj " PTR_FORMAT " in region " HR_FORMAT,
561 p2i(obj), HR_FORMAT_PARAMS(to));
562 print_object(&ls, obj);
563 }
564 log.error("----------");
565 _failures = true;
566 failed = true;
567 _n_failures++;
568 }
569 }
570 }
571 };
572
573 class VerifyRemSetClosure : public G1VerificationClosure {
574 public:
575 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
576 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
577 virtual void do_oop(oop* p) { do_oop_work(p); }
578
579 template <class T>
580 void do_oop_work(T* p) {
581 assert(_containing_obj != NULL, "Precondition");
582 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
583 "Precondition");
584 verify_remembered_set(p);
585 }
586
587 template <class T>
588 void verify_remembered_set(T* p) {
589 T heap_oop = RawAccess<>::oop_load(p);
590 Log(gc, verify) log;
591 if (!CompressedOops::is_null(heap_oop)) {
592 oop obj = CompressedOops::decode_not_null(heap_oop);
593 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
594 HeapRegion* to = _g1h->heap_region_containing(obj);
595 if (from != NULL && to != NULL &&
596 from != to &&
597 !to->is_pinned() &&
598 to->rem_set()->is_complete()) {
599 jbyte cv_obj = *_ct->byte_for_const(_containing_obj);
600 jbyte cv_field = *_ct->byte_for_const(p);
601 const jbyte dirty = G1CardTable::dirty_card_val();
602
603 bool is_bad = !(from->is_young()
604 || to->rem_set()->contains_reference(p)
605 || (_containing_obj->is_objArray() ?
606 cv_field == dirty :
607 cv_obj == dirty || cv_field == dirty));
608 if (is_bad) {
609 MutexLocker x(ParGCRareEvent_lock,
610 Mutex::_no_safepoint_check_flag);
611
612 if (!_failures) {
613 log.error("----------");
614 }
615 log.error("Missing rem set entry:");
616 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT,
617 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
618 ResourceMark rm;
619 LogStream ls(log.error());
620 _containing_obj->print_on(&ls);
621 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
622 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
623 if (oopDesc::is_oop(obj)) {
624 obj->print_on(&ls);
625 }
626 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
627 log.error("----------");
628 _failures = true;
629 _n_failures++;
630 }
631 }
632 }
633 }
634 };
635
636 // Closure that applies the given two closures in sequence.
637 class G1Mux2Closure : public BasicOopIterateClosure {
638 OopClosure* _c1;
639 OopClosure* _c2;
640 public:
641 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
642 template <class T> inline void do_oop_work(T* p) {
643 // Apply first closure; then apply the second.
644 _c1->do_oop(p);
645 _c2->do_oop(p);
646 }
647 virtual inline void do_oop(oop* p) { do_oop_work(p); }
648 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
649
650 // This closure provides its own oop verification code.
651 debug_only(virtual bool should_verify_oops() { return false; })
652 };
653
654 void HeapRegion::verify(VerifyOption vo,
655 bool* failures) const {
656 G1CollectedHeap* g1h = G1CollectedHeap::heap();
657 *failures = false;
658 HeapWord* p = bottom();
659 HeapWord* prev_p = NULL;
660 VerifyLiveClosure vl_cl(g1h, vo);
661 VerifyRemSetClosure vr_cl(g1h, vo);
662 bool is_region_humongous = is_humongous();
663 size_t object_num = 0;
664 while (p < top()) {
665 oop obj = oop(p);
666 size_t obj_size = block_size(p);
667 object_num += 1;
668
669 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
670 if (oopDesc::is_oop(obj)) {
671 Klass* klass = obj->klass();
672 bool is_metaspace_object = Metaspace::contains(klass);
673 if (!is_metaspace_object) {
674 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
675 "not metadata", p2i(klass), p2i(obj));
676 *failures = true;
677 return;
678 } else if (!klass->is_klass()) {
679 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
680 "not a klass", p2i(klass), p2i(obj));
681 *failures = true;
682 return;
683 } else {
684 vl_cl.set_containing_obj(obj);
685 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) {
686 // verify liveness and rem_set
687 vr_cl.set_containing_obj(obj);
688 G1Mux2Closure mux(&vl_cl, &vr_cl);
689 obj->oop_iterate(&mux);
690
691 if (vr_cl.failures()) {
692 *failures = true;
693 }
694 if (G1MaxVerifyFailures >= 0 &&
695 vr_cl.n_failures() >= G1MaxVerifyFailures) {
696 return;
697 }
698 } else {
699 // verify only liveness
700 obj->oop_iterate(&vl_cl);
701 }
702 if (vl_cl.failures()) {
703 *failures = true;
704 }
705 if (G1MaxVerifyFailures >= 0 &&
706 vl_cl.n_failures() >= G1MaxVerifyFailures) {
707 return;
708 }
709 }
710 } else {
711 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
712 *failures = true;
713 return;
714 }
715 }
716 prev_p = p;
717 p += obj_size;
718 }
719
720 if (!is_young() && !is_empty()) {
721 _bot_part.verify();
722 }
723
724 if (is_region_humongous) {
725 oop obj = oop(this->humongous_start_region()->bottom());
726 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) {
727 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
728 *failures = true;
729 return;
730 }
731 }
732
733 if (!is_region_humongous && p != top()) {
734 log_error(gc, verify)("end of last object " PTR_FORMAT " "
735 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
736 *failures = true;
737 return;
738 }
739
740 HeapWord* the_end = end();
741 // Do some extra BOT consistency checking for addresses in the
742 // range [top, end). BOT look-ups in this range should yield
743 // top. No point in doing that if top == end (there's nothing there).
744 if (p < the_end) {
745 // Look up top
746 HeapWord* addr_1 = p;
747 HeapWord* b_start_1 = _bot_part.block_start_const(addr_1);
748 if (b_start_1 != p) {
749 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
750 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
751 p2i(addr_1), p2i(b_start_1), p2i(p));
752 *failures = true;
753 return;
754 }
755
756 // Look up top + 1
757 HeapWord* addr_2 = p + 1;
758 if (addr_2 < the_end) {
759 HeapWord* b_start_2 = _bot_part.block_start_const(addr_2);
760 if (b_start_2 != p) {
761 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
762 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
763 p2i(addr_2), p2i(b_start_2), p2i(p));
764 *failures = true;
765 return;
766 }
767 }
768
769 // Look up an address between top and end
770 size_t diff = pointer_delta(the_end, p) / 2;
771 HeapWord* addr_3 = p + diff;
772 if (addr_3 < the_end) {
773 HeapWord* b_start_3 = _bot_part.block_start_const(addr_3);
774 if (b_start_3 != p) {
775 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
776 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
777 p2i(addr_3), p2i(b_start_3), p2i(p));
778 *failures = true;
779 return;
780 }
781 }
782
783 // Look up end - 1
784 HeapWord* addr_4 = the_end - 1;
785 HeapWord* b_start_4 = _bot_part.block_start_const(addr_4);
786 if (b_start_4 != p) {
787 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
788 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
789 p2i(addr_4), p2i(b_start_4), p2i(p));
790 *failures = true;
791 return;
792 }
793 }
794
795 verify_strong_code_roots(vo, failures);
796 }
797
798 void HeapRegion::verify() const {
799 bool dummy = false;
800 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
801 }
802
803 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
804 G1CollectedHeap* g1h = G1CollectedHeap::heap();
805 *failures = false;
806 HeapWord* p = bottom();
807 HeapWord* prev_p = NULL;
808 VerifyRemSetClosure vr_cl(g1h, vo);
809 while (p < top()) {
810 oop obj = oop(p);
811 size_t obj_size = block_size(p);
812
813 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
814 if (oopDesc::is_oop(obj)) {
815 vr_cl.set_containing_obj(obj);
816 obj->oop_iterate(&vr_cl);
817
818 if (vr_cl.failures()) {
819 *failures = true;
820 }
821 if (G1MaxVerifyFailures >= 0 &&
822 vr_cl.n_failures() >= G1MaxVerifyFailures) {
823 return;
824 }
825 } else {
826 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
827 *failures = true;
828 return;
829 }
830 }
831
832 prev_p = p;
833 p += obj_size;
834 }
835 }
836
837 void HeapRegion::verify_rem_set() const {
838 bool failures = false;
839 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
840 guarantee(!failures, "HeapRegion RemSet verification failed");
841 }
842
843 void HeapRegion::clear(bool mangle_space) {
844 set_top(bottom());
845 set_compaction_top(bottom());
846
847 if (ZapUnusedHeapArea && mangle_space) {
848 mangle_unused_area();
849 }
850 reset_bot();
851 }
852
853 #ifndef PRODUCT
854 void HeapRegion::mangle_unused_area() {
855 SpaceMangler::mangle_region(MemRegion(top(), end()));
856 }
857 #endif
858
859 HeapWord* HeapRegion::initialize_threshold() {
860 return _bot_part.initialize_threshold();
861 }
862
863 HeapWord* HeapRegion::cross_threshold(HeapWord* start, HeapWord* end) {
864 _bot_part.alloc_block(start, end);
865 return _bot_part.threshold();
866 }
867
868 void HeapRegion::object_iterate(ObjectClosure* blk) {
869 HeapWord* p = bottom();
870 while (p < top()) {
871 if (block_is_obj(p)) {
872 blk->do_object(oop(p));
873 }
874 p += block_size(p);
875 }
876 }