1 /*
2 * Copyright (c) 2001, 2017, 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/g1HeapRegionTraceType.hpp"
30 #include "gc/g1/g1OopClosures.inline.hpp"
31 #include "gc/g1/heapRegion.inline.hpp"
32 #include "gc/g1/heapRegionBounds.inline.hpp"
33 #include "gc/g1/heapRegionManager.inline.hpp"
34 #include "gc/g1/heapRegionRemSet.hpp"
35 #include "gc/g1/heapRegionTracer.hpp"
36 #include "gc/shared/genOopClosures.inline.hpp"
37 #include "gc/shared/space.inline.hpp"
38 #include "logging/log.hpp"
39 #include "logging/logStream.hpp"
40 #include "memory/iterator.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "runtime/atomic.hpp"
44 #include "runtime/orderAccess.inline.hpp"
45 #include "utilities/growableArray.hpp"
46
47 int HeapRegion::LogOfHRGrainBytes = 0;
48 int HeapRegion::LogOfHRGrainWords = 0;
49 size_t HeapRegion::GrainBytes = 0;
50 size_t HeapRegion::GrainWords = 0;
51 size_t HeapRegion::CardsPerRegion = 0;
52
53 size_t HeapRegion::max_region_size() {
54 return HeapRegionBounds::max_size();
55 }
56
57 size_t HeapRegion::min_region_size_in_words() {
58 return HeapRegionBounds::min_size() >> LogHeapWordSize;
59 }
60
61 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
62 size_t region_size = G1HeapRegionSize;
63 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
64 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2;
65 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(),
66 HeapRegionBounds::min_size());
67 }
68
69 int region_size_log = log2_long((jlong) region_size);
70 // Recalculate the region size to make sure it's a power of
71 // 2. This means that region_size is the largest power of 2 that's
72 // <= what we've calculated so far.
73 region_size = ((size_t)1 << region_size_log);
74
75 // Now make sure that we don't go over or under our limits.
76 if (region_size < HeapRegionBounds::min_size()) {
77 region_size = HeapRegionBounds::min_size();
78 } else if (region_size > HeapRegionBounds::max_size()) {
79 region_size = HeapRegionBounds::max_size();
80 }
81
82 // And recalculate the log.
83 region_size_log = log2_long((jlong) region_size);
84
85 // Now, set up the globals.
86 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
87 LogOfHRGrainBytes = region_size_log;
88
89 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
90 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
91
92 guarantee(GrainBytes == 0, "we should only set it once");
93 // The cast to int is safe, given that we've bounded region_size by
94 // MIN_REGION_SIZE and MAX_REGION_SIZE.
95 GrainBytes = region_size;
96 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M);
97
98 guarantee(GrainWords == 0, "we should only set it once");
99 GrainWords = GrainBytes >> LogHeapWordSize;
100 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
101
102 guarantee(CardsPerRegion == 0, "we should only set it once");
103 CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift;
104
105 if (G1HeapRegionSize != GrainBytes) {
106 FLAG_SET_ERGO(size_t, G1HeapRegionSize, GrainBytes);
107 }
108 }
109
110 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) {
111 assert(_humongous_start_region == NULL,
112 "we should have already filtered out humongous regions");
113 assert(!in_collection_set(),
114 "Should not clear heap region %u in the collection set", hrm_index());
115
116 set_young_index_in_cset(-1);
117 uninstall_surv_rate_group();
118 set_free();
119 reset_pre_dummy_top();
120
121 if (!keep_remset) {
122 if (locked) {
123 rem_set()->clear_locked();
124 } else {
125 rem_set()->clear();
126 }
127 }
128
129 zero_marked_bytes();
130
131 init_top_at_mark_start();
132 _gc_time_stamp = G1CollectedHeap::heap()->get_gc_time_stamp();
133 if (clear_space) clear(SpaceDecorator::Mangle);
134 }
135
136 void HeapRegion::par_clear() {
137 assert(used() == 0, "the region should have been already cleared");
138 assert(capacity() == HeapRegion::GrainBytes, "should be back to normal");
139 HeapRegionRemSet* hrrs = rem_set();
140 hrrs->clear();
141 CardTableModRefBS* ct_bs =
142 barrier_set_cast<CardTableModRefBS>(G1CollectedHeap::heap()->barrier_set());
143 ct_bs->clear(MemRegion(bottom(), end()));
144 }
145
146 void HeapRegion::calc_gc_efficiency() {
147 // GC efficiency is the ratio of how much space would be
148 // reclaimed over how long we predict it would take to reclaim it.
149 G1CollectedHeap* g1h = G1CollectedHeap::heap();
150 G1Policy* g1p = g1h->g1_policy();
151
152 // Retrieve a prediction of the elapsed time for this region for
153 // a mixed gc because the region will only be evacuated during a
154 // mixed gc.
155 double region_elapsed_time_ms =
156 g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */);
157 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
158 }
159
160 void HeapRegion::set_free() {
161 report_region_type_change(G1HeapRegionTraceType::Free);
162 _type.set_free();
163 }
164
165 void HeapRegion::set_eden() {
166 report_region_type_change(G1HeapRegionTraceType::Eden);
167 _type.set_eden();
168 }
169
170 void HeapRegion::set_eden_pre_gc() {
171 report_region_type_change(G1HeapRegionTraceType::Eden);
172 _type.set_eden_pre_gc();
173 }
174
175 void HeapRegion::set_survivor() {
176 report_region_type_change(G1HeapRegionTraceType::Survivor);
177 _type.set_survivor();
178 }
179
180 void HeapRegion::move_to_old() {
181 if (_type.relabel_as_old()) {
182 report_region_type_change(G1HeapRegionTraceType::Old);
183 }
184 }
185
186 void HeapRegion::set_old() {
187 report_region_type_change(G1HeapRegionTraceType::Old);
188 _type.set_old();
189 }
190
191 void HeapRegion::set_open_archive() {
192 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
193 _type.set_open_archive();
194 }
195
196 void HeapRegion::set_closed_archive() {
197 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
198 _type.set_closed_archive();
199 }
200
201 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
202 assert(!is_humongous(), "sanity / pre-condition");
203 assert(top() == bottom(), "should be empty");
204
205 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
206 _type.set_starts_humongous();
207 _humongous_start_region = this;
208
209 _bot_part.set_for_starts_humongous(obj_top, fill_size);
210 }
211
212 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
213 assert(!is_humongous(), "sanity / pre-condition");
214 assert(top() == bottom(), "should be empty");
215 assert(first_hr->is_starts_humongous(), "pre-condition");
216
217 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
218 _type.set_continues_humongous();
219 _humongous_start_region = first_hr;
220
221 _bot_part.set_object_can_span(true);
222 }
223
224 void HeapRegion::clear_humongous() {
225 assert(is_humongous(), "pre-condition");
226
227 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
228 _humongous_start_region = NULL;
229
230 _bot_part.set_object_can_span(false);
231 }
232
233 HeapRegion::HeapRegion(uint hrm_index,
234 G1BlockOffsetTable* bot,
235 MemRegion mr) :
236 G1ContiguousSpace(bot),
237 _hrm_index(hrm_index),
238 _humongous_start_region(NULL),
239 _evacuation_failed(false),
240 _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0),
241 _next(NULL), _prev(NULL),
242 #ifdef ASSERT
243 _containing_set(NULL),
244 #endif // ASSERT
245 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
246 _rem_set(NULL), _recorded_rs_length(0), _predicted_elapsed_time_ms(0)
247 {
248 _rem_set = new HeapRegionRemSet(bot, this);
249
250 initialize(mr);
251 }
252
253 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
254 assert(_rem_set->is_empty(), "Remembered set must be empty");
255
256 G1ContiguousSpace::initialize(mr, clear_space, mangle_space);
257
258 hr_clear(false /*par*/, false /*clear_space*/);
259 set_top(bottom());
260 record_timestamp();
261 }
262
263 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
264 HeapRegionTracer::send_region_type_change(_hrm_index,
265 get_trace_type(),
266 to,
267 (uintptr_t)bottom(),
268 used());
269 }
270
271 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
272 bool during_conc_mark) {
273 // We always recreate the prev marking info and we'll explicitly
274 // mark all objects we find to be self-forwarded on the prev
275 // bitmap. So all objects need to be below PTAMS.
276 _prev_marked_bytes = 0;
277
278 if (during_initial_mark) {
279 // During initial-mark, we'll also explicitly mark all objects
280 // we find to be self-forwarded on the next bitmap. So all
281 // objects need to be below NTAMS.
282 _next_top_at_mark_start = top();
283 _next_marked_bytes = 0;
284 } else if (during_conc_mark) {
285 // During concurrent mark, all objects in the CSet (including
286 // the ones we find to be self-forwarded) are implicitly live.
287 // So all objects need to be above NTAMS.
288 _next_top_at_mark_start = bottom();
289 _next_marked_bytes = 0;
290 }
291 }
292
293 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
294 assert(marked_bytes <= used(),
295 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
296 _prev_top_at_mark_start = top();
297 _prev_marked_bytes = marked_bytes;
298 }
299
300 // Code roots support
301
302 void HeapRegion::add_strong_code_root(nmethod* nm) {
303 HeapRegionRemSet* hrrs = rem_set();
304 hrrs->add_strong_code_root(nm);
305 }
306
307 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
308 assert_locked_or_safepoint(CodeCache_lock);
309 HeapRegionRemSet* hrrs = rem_set();
310 hrrs->add_strong_code_root_locked(nm);
311 }
312
313 void HeapRegion::remove_strong_code_root(nmethod* nm) {
314 HeapRegionRemSet* hrrs = rem_set();
315 hrrs->remove_strong_code_root(nm);
316 }
317
318 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
319 HeapRegionRemSet* hrrs = rem_set();
320 hrrs->strong_code_roots_do(blk);
321 }
322
323 class VerifyStrongCodeRootOopClosure: public OopClosure {
324 const HeapRegion* _hr;
325 bool _failures;
326 bool _has_oops_in_region;
327
328 template <class T> void do_oop_work(T* p) {
329 T heap_oop = oopDesc::load_heap_oop(p);
330 if (!oopDesc::is_null(heap_oop)) {
331 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
332
333 // Note: not all the oops embedded in the nmethod are in the
334 // current region. We only look at those which are.
335 if (_hr->is_in(obj)) {
336 // Object is in the region. Check that its less than top
337 if (_hr->top() <= (HeapWord*)obj) {
338 // Object is above top
339 log_error(gc, verify)("Object " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ") is above top " PTR_FORMAT,
340 p2i(obj), p2i(_hr->bottom()), p2i(_hr->end()), p2i(_hr->top()));
341 _failures = true;
342 return;
343 }
344 // Nmethod has at least one oop in the current region
345 _has_oops_in_region = true;
346 }
347 }
348 }
349
350 public:
351 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
352 _hr(hr), _failures(false), _has_oops_in_region(false) {}
353
354 void do_oop(narrowOop* p) { do_oop_work(p); }
355 void do_oop(oop* p) { do_oop_work(p); }
356
357 bool failures() { return _failures; }
358 bool has_oops_in_region() { return _has_oops_in_region; }
359 };
360
361 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
362 const HeapRegion* _hr;
363 bool _failures;
364 public:
365 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
366 _hr(hr), _failures(false) {}
367
368 void do_code_blob(CodeBlob* cb) {
369 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
370 if (nm != NULL) {
371 // Verify that the nemthod is live
372 if (!nm->is_alive()) {
373 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
374 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
375 _failures = true;
376 } else {
377 VerifyStrongCodeRootOopClosure oop_cl(_hr);
378 nm->oops_do(&oop_cl);
379 if (!oop_cl.has_oops_in_region()) {
380 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
381 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
382 _failures = true;
383 } else if (oop_cl.failures()) {
384 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
385 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
386 _failures = true;
387 }
388 }
389 }
390 }
391
392 bool failures() { return _failures; }
393 };
394
395 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
396 if (!G1VerifyHeapRegionCodeRoots) {
397 // We're not verifying code roots.
398 return;
399 }
400 if (vo == VerifyOption_G1UseFullMarking) {
401 // Marking verification during a full GC is performed after class
402 // unloading, code cache unloading, etc so the strong code roots
403 // attached to each heap region are in an inconsistent state. They won't
404 // be consistent until the strong code roots are rebuilt after the
405 // actual GC. Skip verifying the strong code roots in this particular
406 // time.
407 assert(VerifyDuringGC, "only way to get here");
408 return;
409 }
410
411 HeapRegionRemSet* hrrs = rem_set();
412 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
413
414 // if this region is empty then there should be no entries
415 // on its strong code root list
416 if (is_empty()) {
417 if (strong_code_roots_length > 0) {
418 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] is empty but has " SIZE_FORMAT " code root entries",
419 p2i(bottom()), p2i(end()), strong_code_roots_length);
420 *failures = true;
421 }
422 return;
423 }
424
425 if (is_continues_humongous()) {
426 if (strong_code_roots_length > 0) {
427 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
428 HR_FORMAT_PARAMS(this), strong_code_roots_length);
429 *failures = true;
430 }
431 return;
432 }
433
434 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
435 strong_code_roots_do(&cb_cl);
436
437 if (cb_cl.failures()) {
438 *failures = true;
439 }
440 }
441
442 void HeapRegion::print() const { print_on(tty); }
443 void HeapRegion::print_on(outputStream* st) const {
444 st->print("|%4u", this->_hrm_index);
445 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
446 p2i(bottom()), p2i(top()), p2i(end()));
447 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
448 st->print("|%2s", get_short_type_str());
449 if (in_collection_set()) {
450 st->print("|CS");
451 } else {
452 st->print("| ");
453 }
454 st->print("|TS%3u", _gc_time_stamp);
455 st->print_cr("|TAMS " PTR_FORMAT ", " PTR_FORMAT "|",
456 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()));
457 }
458
459 class G1VerificationClosure : public OopClosure {
460 protected:
461 G1CollectedHeap* _g1h;
462 CardTableModRefBS* _bs;
463 oop _containing_obj;
464 bool _failures;
465 int _n_failures;
466 VerifyOption _vo;
467 public:
468 // _vo == UsePrevMarking -> use "prev" marking information,
469 // _vo == UseNextMarking -> use "next" marking information,
470 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
471 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
472 _g1h(g1h), _bs(barrier_set_cast<CardTableModRefBS>(g1h->barrier_set())),
473 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
474 }
475
476 void set_containing_obj(oop obj) {
477 _containing_obj = obj;
478 }
479
480 bool failures() { return _failures; }
481 int n_failures() { return _n_failures; }
482
483 void print_object(outputStream* out, oop obj) {
484 #ifdef PRODUCT
485 Klass* k = obj->klass();
486 const char* class_name = k->external_name();
487 out->print_cr("class name %s", class_name);
488 #else // PRODUCT
489 obj->print_on(out);
490 #endif // PRODUCT
491 }
492 };
493
494 class VerifyLiveClosure : public G1VerificationClosure {
495 public:
496 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
497 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
498 virtual void do_oop(oop* p) { do_oop_work(p); }
499
500 template <class T>
501 void do_oop_work(T* p) {
502 assert(_containing_obj != NULL, "Precondition");
503 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
504 "Precondition");
505 verify_liveness(p);
506 }
507
508 template <class T>
509 void verify_liveness(T* p) {
510 T heap_oop = oopDesc::load_heap_oop(p);
511 Log(gc, verify) log;
512 if (!oopDesc::is_null(heap_oop)) {
513 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
514 bool failed = false;
515 if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
516 MutexLockerEx x(ParGCRareEvent_lock,
517 Mutex::_no_safepoint_check_flag);
518
519 if (!_failures) {
520 log.error("----------");
521 }
522 ResourceMark rm;
523 if (!_g1h->is_in_closed_subset(obj)) {
524 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
525 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
526 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end()));
527 LogStream ls(log.error());
528 print_object(&ls, _containing_obj);
529 log.error("points to obj " PTR_FORMAT " not in the heap", p2i(obj));
530 } else {
531 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
532 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
533 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
534 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end()));
535 LogStream ls(log.error());
536 print_object(&ls, _containing_obj);
537 log.error("points to dead obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
538 p2i(obj), p2i(to->bottom()), p2i(to->end()));
539 print_object(&ls, obj);
540 }
541 log.error("----------");
542 _failures = true;
543 failed = true;
544 _n_failures++;
545 }
546 }
547 }
548 };
549
550 class VerifyRemSetClosure : public G1VerificationClosure {
551 public:
552 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
553 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
554 virtual void do_oop(oop* p) { do_oop_work(p); }
555
556 template <class T>
557 void do_oop_work(T* p) {
558 assert(_containing_obj != NULL, "Precondition");
559 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
560 "Precondition");
561 verify_remembered_set(p);
562 }
563
564 template <class T>
565 void verify_remembered_set(T* p) {
566 T heap_oop = oopDesc::load_heap_oop(p);
567 Log(gc, verify) log;
568 if (!oopDesc::is_null(heap_oop)) {
569 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
570 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
571 HeapRegion* to = _g1h->heap_region_containing(obj);
572 if (from != NULL && to != NULL &&
573 from != to &&
574 !to->is_pinned()) {
575 jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
576 jbyte cv_field = *_bs->byte_for_const(p);
577 const jbyte dirty = CardTableModRefBS::dirty_card_val();
578
579 bool is_bad = !(from->is_young()
580 || to->rem_set()->contains_reference(p)
581 || (_containing_obj->is_objArray() ?
582 cv_field == dirty :
583 cv_obj == dirty || cv_field == dirty));
584 if (is_bad) {
585 MutexLockerEx x(ParGCRareEvent_lock,
586 Mutex::_no_safepoint_check_flag);
587
588 if (!_failures) {
589 log.error("----------");
590 }
591 log.error("Missing rem set entry:");
592 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT ", in region " HR_FORMAT,
593 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
594 ResourceMark rm;
595 LogStream ls(log.error());
596 _containing_obj->print_on(&ls);
597 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT, p2i(obj), HR_FORMAT_PARAMS(to));
598 if (oopDesc::is_oop(obj)) {
599 obj->print_on(&ls);
600 }
601 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
602 log.error("----------");
603 _failures = true;
604 _n_failures++;
605 }
606 }
607 }
608 }
609 };
610
611 // Closure that applies the given two closures in sequence.
612 class G1Mux2Closure : public OopClosure {
613 OopClosure* _c1;
614 OopClosure* _c2;
615 public:
616 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
617 template <class T> inline void do_oop_work(T* p) {
618 // Apply first closure; then apply the second.
619 _c1->do_oop(p);
620 _c2->do_oop(p);
621 }
622 virtual inline void do_oop(oop* p) { do_oop_work(p); }
623 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
624 };
625
626 // This really ought to be commoned up into OffsetTableContigSpace somehow.
627 // We would need a mechanism to make that code skip dead objects.
628
629 void HeapRegion::verify(VerifyOption vo,
630 bool* failures) const {
631 G1CollectedHeap* g1 = G1CollectedHeap::heap();
632 *failures = false;
633 HeapWord* p = bottom();
634 HeapWord* prev_p = NULL;
635 VerifyLiveClosure vl_cl(g1, vo);
636 VerifyRemSetClosure vr_cl(g1, vo);
637 bool is_region_humongous = is_humongous();
638 size_t object_num = 0;
639 while (p < top()) {
640 oop obj = oop(p);
641 size_t obj_size = block_size(p);
642 object_num += 1;
643
644 if (!g1->is_obj_dead_cond(obj, this, vo)) {
645 if (oopDesc::is_oop(obj)) {
646 Klass* klass = obj->klass();
647 bool is_metaspace_object = Metaspace::contains(klass) ||
648 (vo == VerifyOption_G1UsePrevMarking &&
649 ClassLoaderDataGraph::unload_list_contains(klass));
650 if (!is_metaspace_object) {
651 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
652 "not metadata", p2i(klass), p2i(obj));
653 *failures = true;
654 return;
655 } else if (!klass->is_klass()) {
656 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
657 "not a klass", p2i(klass), p2i(obj));
658 *failures = true;
659 return;
660 } else {
661 vl_cl.set_containing_obj(obj);
662 if (!g1->collector_state()->full_collection() || G1VerifyRSetsDuringFullGC) {
663 // verify liveness and rem_set
664 vr_cl.set_containing_obj(obj);
665 G1Mux2Closure mux(&vl_cl, &vr_cl);
666 obj->oop_iterate_no_header(&mux);
667
668 if (vr_cl.failures()) {
669 *failures = true;
670 }
671 if (G1MaxVerifyFailures >= 0 &&
672 vr_cl.n_failures() >= G1MaxVerifyFailures) {
673 return;
674 }
675 } else {
676 // verify only liveness
677 obj->oop_iterate_no_header(&vl_cl);
678 }
679 if (vl_cl.failures()) {
680 *failures = true;
681 }
682 if (G1MaxVerifyFailures >= 0 &&
683 vl_cl.n_failures() >= G1MaxVerifyFailures) {
684 return;
685 }
686 }
687 } else {
688 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
689 *failures = true;
690 return;
691 }
692 }
693 prev_p = p;
694 p += obj_size;
695 }
696
697 if (!is_young() && !is_empty()) {
698 _bot_part.verify();
699 }
700
701 if (is_region_humongous) {
702 oop obj = oop(this->humongous_start_region()->bottom());
703 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) {
704 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
705 *failures = true;
706 return;
707 }
708 }
709
710 if (!is_region_humongous && p != top()) {
711 log_error(gc, verify)("end of last object " PTR_FORMAT " "
712 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
713 *failures = true;
714 return;
715 }
716
717 HeapWord* the_end = end();
718 // Do some extra BOT consistency checking for addresses in the
719 // range [top, end). BOT look-ups in this range should yield
720 // top. No point in doing that if top == end (there's nothing there).
721 if (p < the_end) {
722 // Look up top
723 HeapWord* addr_1 = p;
724 HeapWord* b_start_1 = _bot_part.block_start_const(addr_1);
725 if (b_start_1 != p) {
726 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
727 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
728 p2i(addr_1), p2i(b_start_1), p2i(p));
729 *failures = true;
730 return;
731 }
732
733 // Look up top + 1
734 HeapWord* addr_2 = p + 1;
735 if (addr_2 < the_end) {
736 HeapWord* b_start_2 = _bot_part.block_start_const(addr_2);
737 if (b_start_2 != p) {
738 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
739 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
740 p2i(addr_2), p2i(b_start_2), p2i(p));
741 *failures = true;
742 return;
743 }
744 }
745
746 // Look up an address between top and end
747 size_t diff = pointer_delta(the_end, p) / 2;
748 HeapWord* addr_3 = p + diff;
749 if (addr_3 < the_end) {
750 HeapWord* b_start_3 = _bot_part.block_start_const(addr_3);
751 if (b_start_3 != p) {
752 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
753 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
754 p2i(addr_3), p2i(b_start_3), p2i(p));
755 *failures = true;
756 return;
757 }
758 }
759
760 // Look up end - 1
761 HeapWord* addr_4 = the_end - 1;
762 HeapWord* b_start_4 = _bot_part.block_start_const(addr_4);
763 if (b_start_4 != p) {
764 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
765 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
766 p2i(addr_4), p2i(b_start_4), p2i(p));
767 *failures = true;
768 return;
769 }
770 }
771
772 verify_strong_code_roots(vo, failures);
773 }
774
775 void HeapRegion::verify() const {
776 bool dummy = false;
777 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
778 }
779
780 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
781 G1CollectedHeap* g1 = G1CollectedHeap::heap();
782 *failures = false;
783 HeapWord* p = bottom();
784 HeapWord* prev_p = NULL;
785 VerifyRemSetClosure vr_cl(g1, vo);
786 while (p < top()) {
787 oop obj = oop(p);
788 size_t obj_size = block_size(p);
789
790 if (!g1->is_obj_dead_cond(obj, this, vo)) {
791 if (oopDesc::is_oop(obj)) {
792 vr_cl.set_containing_obj(obj);
793 obj->oop_iterate_no_header(&vr_cl);
794
795 if (vr_cl.failures()) {
796 *failures = true;
797 }
798 if (G1MaxVerifyFailures >= 0 &&
799 vr_cl.n_failures() >= G1MaxVerifyFailures) {
800 return;
801 }
802 } else {
803 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
804 *failures = true;
805 return;
806 }
807 }
808
809 prev_p = p;
810 p += obj_size;
811 }
812 }
813
814 void HeapRegion::verify_rem_set() const {
815 bool failures = false;
816 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
817 guarantee(!failures, "HeapRegion RemSet verification failed");
818 }
819
820 void HeapRegion::prepare_for_compaction(CompactPoint* cp) {
821 // Not used for G1 anymore, but pure virtual in Space.
822 ShouldNotReachHere();
823 }
824
825 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
826 // away eventually.
827
828 void G1ContiguousSpace::clear(bool mangle_space) {
829 set_top(bottom());
830 CompactibleSpace::clear(mangle_space);
831 reset_bot();
832 }
833
834 #ifndef PRODUCT
835 void G1ContiguousSpace::mangle_unused_area() {
836 mangle_unused_area_complete();
837 }
838
839 void G1ContiguousSpace::mangle_unused_area_complete() {
840 SpaceMangler::mangle_region(MemRegion(top(), end()));
841 }
842 #endif
843
844 void G1ContiguousSpace::print() const {
845 print_short();
846 tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
847 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
848 p2i(bottom()), p2i(top()), p2i(_bot_part.threshold()), p2i(end()));
849 }
850
851 HeapWord* G1ContiguousSpace::initialize_threshold() {
852 return _bot_part.initialize_threshold();
853 }
854
855 HeapWord* G1ContiguousSpace::cross_threshold(HeapWord* start,
856 HeapWord* end) {
857 _bot_part.alloc_block(start, end);
858 return _bot_part.threshold();
859 }
860
861 void G1ContiguousSpace::record_timestamp() {
862 G1CollectedHeap* g1h = G1CollectedHeap::heap();
863 uint curr_gc_time_stamp = g1h->get_gc_time_stamp();
864
865 if (_gc_time_stamp < curr_gc_time_stamp) {
866 _gc_time_stamp = curr_gc_time_stamp;
867 }
868 }
869
870 void G1ContiguousSpace::safe_object_iterate(ObjectClosure* blk) {
871 object_iterate(blk);
872 }
873
874 void G1ContiguousSpace::object_iterate(ObjectClosure* blk) {
875 HeapWord* p = bottom();
876 while (p < top()) {
877 if (block_is_obj(p)) {
878 blk->do_object(oop(p));
879 }
880 p += block_size(p);
881 }
882 }
883
884 G1ContiguousSpace::G1ContiguousSpace(G1BlockOffsetTable* bot) :
885 _bot_part(bot, this),
886 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
887 _gc_time_stamp(0)
888 {
889 }
890
891 void G1ContiguousSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
892 CompactibleSpace::initialize(mr, clear_space, mangle_space);
893 _top = bottom();
894 set_saved_mark_word(NULL);
895 reset_bot();
896 }