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
46 int HeapRegion::LogOfHRGrainBytes = 0;
47 int HeapRegion::LogOfHRGrainWords = 0;
48 size_t HeapRegion::GrainBytes = 0;
49 size_t HeapRegion::GrainWords = 0;
50 size_t HeapRegion::CardsPerRegion = 0;
51
52 size_t HeapRegion::max_region_size() {
53 return HeapRegionBounds::max_size();
54 }
55
56 size_t HeapRegion::min_region_size_in_words() {
57 return HeapRegionBounds::min_size() >> LogHeapWordSize;
58 }
59
60 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
61 size_t region_size = G1HeapRegionSize;
62 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
63 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2;
64 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(),
65 HeapRegionBounds::min_size());
66 }
67
68 int region_size_log = log2_long((jlong) region_size);
69 // Recalculate the region size to make sure it's a power of
70 // 2. This means that region_size is the largest power of 2 that's
71 // <= what we've calculated so far.
72 region_size = ((size_t)1 << region_size_log);
73
74 // Now make sure that we don't go over or under our limits.
75 if (region_size < HeapRegionBounds::min_size()) {
76 region_size = HeapRegionBounds::min_size();
77 } else if (region_size > HeapRegionBounds::max_size()) {
78 region_size = HeapRegionBounds::max_size();
79 }
80
81 // And recalculate the log.
82 region_size_log = log2_long((jlong) region_size);
83
84 // Now, set up the globals.
85 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
86 LogOfHRGrainBytes = region_size_log;
87
88 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
89 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
90
91 guarantee(GrainBytes == 0, "we should only set it once");
92 // The cast to int is safe, given that we've bounded region_size by
93 // MIN_REGION_SIZE and MAX_REGION_SIZE.
94 GrainBytes = region_size;
95 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M);
96
97 guarantee(GrainWords == 0, "we should only set it once");
98 GrainWords = GrainBytes >> LogHeapWordSize;
99 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
100
101 guarantee(CardsPerRegion == 0, "we should only set it once");
102 CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift;
103
104 if (G1HeapRegionSize != GrainBytes) {
105 FLAG_SET_ERGO(size_t, G1HeapRegionSize, GrainBytes);
106 }
107 }
108
109 void HeapRegion::reset_after_compaction() {
110 G1ContiguousSpace::reset_after_compaction();
111 // After a compaction the mark bitmap is invalid, so we must
112 // treat all objects as being inside the unmarked area.
113 zero_marked_bytes();
114 init_top_at_mark_start();
115 }
116
117 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) {
118 assert(_humongous_start_region == NULL,
119 "we should have already filtered out humongous regions");
120 assert(!in_collection_set(),
121 "Should not clear heap region %u in the collection set", hrm_index());
122
123 set_allocation_context(AllocationContext::system());
124 set_young_index_in_cset(-1);
125 uninstall_surv_rate_group();
126 set_free();
127 reset_pre_dummy_top();
128
129 if (!keep_remset) {
130 if (locked) {
131 rem_set()->clear_locked();
132 } else {
133 rem_set()->clear();
134 }
135 }
136
137 zero_marked_bytes();
138
139 init_top_at_mark_start();
140 _gc_time_stamp = G1CollectedHeap::heap()->get_gc_time_stamp();
141 if (clear_space) clear(SpaceDecorator::Mangle);
142 }
143
144 void HeapRegion::par_clear() {
145 assert(used() == 0, "the region should have been already cleared");
146 assert(capacity() == HeapRegion::GrainBytes, "should be back to normal");
147 HeapRegionRemSet* hrrs = rem_set();
148 hrrs->clear();
149 CardTableModRefBS* ct_bs =
150 barrier_set_cast<CardTableModRefBS>(G1CollectedHeap::heap()->barrier_set());
151 ct_bs->clear(MemRegion(bottom(), end()));
152 }
153
154 void HeapRegion::calc_gc_efficiency() {
155 // GC efficiency is the ratio of how much space would be
156 // reclaimed over how long we predict it would take to reclaim it.
157 G1CollectedHeap* g1h = G1CollectedHeap::heap();
158 G1Policy* g1p = g1h->g1_policy();
159
160 // Retrieve a prediction of the elapsed time for this region for
161 // a mixed gc because the region will only be evacuated during a
162 // mixed gc.
163 double region_elapsed_time_ms =
164 g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */);
165 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
166 }
167
168 void HeapRegion::set_free() {
169 report_region_type_change(G1HeapRegionTraceType::Free);
170 _type.set_free();
171 }
172
173 void HeapRegion::set_eden() {
174 report_region_type_change(G1HeapRegionTraceType::Eden);
175 _type.set_eden();
176 }
177
178 void HeapRegion::set_eden_pre_gc() {
179 report_region_type_change(G1HeapRegionTraceType::Eden);
180 _type.set_eden_pre_gc();
181 }
182
183 void HeapRegion::set_survivor() {
184 report_region_type_change(G1HeapRegionTraceType::Survivor);
185 _type.set_survivor();
186 }
187
188 void HeapRegion::move_to_old() {
189 if (_type.relabel_as_old()) {
190 report_region_type_change(G1HeapRegionTraceType::Old);
191 }
192 }
193
194 void HeapRegion::set_old() {
195 report_region_type_change(G1HeapRegionTraceType::Old);
196 _type.set_old();
197 }
198
199 void HeapRegion::set_open_archive() {
200 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
201 _type.set_open_archive();
202 }
203
204 void HeapRegion::set_closed_archive() {
205 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
206 _type.set_closed_archive();
207 }
208
209 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
210 assert(!is_humongous(), "sanity / pre-condition");
211 assert(top() == bottom(), "should be empty");
212
213 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
214 _type.set_starts_humongous();
215 _humongous_start_region = this;
216
217 _bot_part.set_for_starts_humongous(obj_top, fill_size);
218 }
219
220 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
221 assert(!is_humongous(), "sanity / pre-condition");
222 assert(top() == bottom(), "should be empty");
223 assert(first_hr->is_starts_humongous(), "pre-condition");
224
225 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
226 _type.set_continues_humongous();
227 _humongous_start_region = first_hr;
228
229 _bot_part.set_object_can_span(true);
230 }
231
232 void HeapRegion::clear_humongous() {
233 assert(is_humongous(), "pre-condition");
234
235 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
236 _humongous_start_region = NULL;
237
238 _bot_part.set_object_can_span(false);
239 }
240
241 HeapRegion::HeapRegion(uint hrm_index,
242 G1BlockOffsetTable* bot,
243 MemRegion mr) :
244 G1ContiguousSpace(bot),
245 _hrm_index(hrm_index),
246 _allocation_context(AllocationContext::system()),
247 _humongous_start_region(NULL),
248 _evacuation_failed(false),
249 _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0),
250 _next(NULL), _prev(NULL),
251 #ifdef ASSERT
252 _containing_set(NULL),
253 #endif // ASSERT
254 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
255 _rem_set(NULL), _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 G1ContiguousSpace::initialize(mr, clear_space, mangle_space);
266
267 hr_clear(false /*par*/, false /*clear_space*/);
268 set_top(bottom());
269 record_timestamp();
270 }
271
272 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
273 HeapRegionTracer::send_region_type_change(_hrm_index,
274 get_trace_type(),
275 to,
276 (uintptr_t)bottom(),
277 used(),
278 (uint)allocation_context());
279 }
280
281 CompactibleSpace* HeapRegion::next_compaction_space() const {
282 return G1CollectedHeap::heap()->next_compaction_region(this);
283 }
284
285 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
286 bool during_conc_mark) {
287 // We always recreate the prev marking info and we'll explicitly
288 // mark all objects we find to be self-forwarded on the prev
289 // bitmap. So all objects need to be below PTAMS.
290 _prev_marked_bytes = 0;
291
292 if (during_initial_mark) {
293 // During initial-mark, we'll also explicitly mark all objects
294 // we find to be self-forwarded on the next bitmap. So all
295 // objects need to be below NTAMS.
296 _next_top_at_mark_start = top();
297 _next_marked_bytes = 0;
298 } else if (during_conc_mark) {
299 // During concurrent mark, all objects in the CSet (including
300 // the ones we find to be self-forwarded) are implicitly live.
301 // So all objects need to be above NTAMS.
302 _next_top_at_mark_start = bottom();
303 _next_marked_bytes = 0;
304 }
305 }
306
307 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
308 assert(marked_bytes <= used(),
309 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
310 _prev_top_at_mark_start = top();
311 _prev_marked_bytes = marked_bytes;
312 }
313
314 // Code roots support
315
316 void HeapRegion::add_strong_code_root(nmethod* nm) {
317 HeapRegionRemSet* hrrs = rem_set();
318 hrrs->add_strong_code_root(nm);
319 }
320
321 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
322 assert_locked_or_safepoint(CodeCache_lock);
323 HeapRegionRemSet* hrrs = rem_set();
324 hrrs->add_strong_code_root_locked(nm);
325 }
326
327 void HeapRegion::remove_strong_code_root(nmethod* nm) {
328 HeapRegionRemSet* hrrs = rem_set();
329 hrrs->remove_strong_code_root(nm);
330 }
331
332 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
333 HeapRegionRemSet* hrrs = rem_set();
334 hrrs->strong_code_roots_do(blk);
335 }
336
337 class VerifyStrongCodeRootOopClosure: public OopClosure {
338 const HeapRegion* _hr;
339 bool _failures;
340 bool _has_oops_in_region;
341
342 template <class T> void do_oop_work(T* p) {
343 T heap_oop = oopDesc::load_heap_oop(p);
344 if (!oopDesc::is_null(heap_oop)) {
345 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
346
347 // Note: not all the oops embedded in the nmethod are in the
348 // current region. We only look at those which are.
349 if (_hr->is_in(obj)) {
350 // Object is in the region. Check that its less than top
351 if (_hr->top() <= (HeapWord*)obj) {
352 // Object is above top
353 log_error(gc, verify)("Object " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ") is above top " PTR_FORMAT,
354 p2i(obj), p2i(_hr->bottom()), p2i(_hr->end()), p2i(_hr->top()));
355 _failures = true;
356 return;
357 }
358 // Nmethod has at least one oop in the current region
359 _has_oops_in_region = true;
360 }
361 }
362 }
363
364 public:
365 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
366 _hr(hr), _failures(false), _has_oops_in_region(false) {}
367
368 void do_oop(narrowOop* p) { do_oop_work(p); }
369 void do_oop(oop* p) { do_oop_work(p); }
370
371 bool failures() { return _failures; }
372 bool has_oops_in_region() { return _has_oops_in_region; }
373 };
374
375 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
376 const HeapRegion* _hr;
377 bool _failures;
378 public:
379 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
380 _hr(hr), _failures(false) {}
381
382 void do_code_blob(CodeBlob* cb) {
383 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
384 if (nm != NULL) {
385 // Verify that the nemthod is live
386 if (!nm->is_alive()) {
387 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
388 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
389 _failures = true;
390 } else {
391 VerifyStrongCodeRootOopClosure oop_cl(_hr);
392 nm->oops_do(&oop_cl);
393 if (!oop_cl.has_oops_in_region()) {
394 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
395 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
396 _failures = true;
397 } else if (oop_cl.failures()) {
398 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
399 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
400 _failures = true;
401 }
402 }
403 }
404 }
405
406 bool failures() { return _failures; }
407 };
408
409 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
410 if (!G1VerifyHeapRegionCodeRoots) {
411 // We're not verifying code roots.
412 return;
413 }
414 if (vo == VerifyOption_G1UseMarkWord) {
415 // Marking verification during a full GC is performed after class
416 // unloading, code cache unloading, etc so the strong code roots
417 // attached to each heap region are in an inconsistent state. They won't
418 // be consistent until the strong code roots are rebuilt after the
419 // actual GC. Skip verifying the strong code roots in this particular
420 // time.
421 assert(VerifyDuringGC, "only way to get here");
422 return;
423 }
424
425 HeapRegionRemSet* hrrs = rem_set();
426 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
427
428 // if this region is empty then there should be no entries
429 // on its strong code root list
430 if (is_empty()) {
431 if (strong_code_roots_length > 0) {
432 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] is empty but has " SIZE_FORMAT " code root entries",
433 p2i(bottom()), p2i(end()), strong_code_roots_length);
434 *failures = true;
435 }
436 return;
437 }
438
439 if (is_continues_humongous()) {
440 if (strong_code_roots_length > 0) {
441 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
442 HR_FORMAT_PARAMS(this), strong_code_roots_length);
443 *failures = true;
444 }
445 return;
446 }
447
448 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
449 strong_code_roots_do(&cb_cl);
450
451 if (cb_cl.failures()) {
452 *failures = true;
453 }
454 }
455
456 void HeapRegion::print() const { print_on(tty); }
457 void HeapRegion::print_on(outputStream* st) const {
458 st->print("|%4u", this->_hrm_index);
459 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
460 p2i(bottom()), p2i(top()), p2i(end()));
461 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
462 st->print("|%2s", get_short_type_str());
463 if (in_collection_set()) {
464 st->print("|CS");
465 } else {
466 st->print("| ");
467 }
468 st->print("|TS%3u", _gc_time_stamp);
469 st->print("|AC%3u", allocation_context());
470 st->print_cr("|TAMS " PTR_FORMAT ", " PTR_FORMAT "|",
471 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()));
472 }
473
474 class G1VerificationClosure : public OopClosure {
475 protected:
476 G1CollectedHeap* _g1h;
477 CardTableModRefBS* _bs;
478 oop _containing_obj;
479 bool _failures;
480 int _n_failures;
481 VerifyOption _vo;
482 public:
483 // _vo == UsePrevMarking -> use "prev" marking information,
484 // _vo == UseNextMarking -> use "next" marking information,
485 // _vo == UseMarkWord -> use mark word from object header.
486 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
487 _g1h(g1h), _bs(barrier_set_cast<CardTableModRefBS>(g1h->barrier_set())),
488 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
489 }
490
491 void set_containing_obj(oop obj) {
492 _containing_obj = obj;
493 }
494
495 bool failures() { return _failures; }
496 int n_failures() { return _n_failures; }
497
498 void print_object(outputStream* out, oop obj) {
499 #ifdef PRODUCT
500 Klass* k = obj->klass();
501 const char* class_name = k->external_name();
502 out->print_cr("class name %s", class_name);
503 #else // PRODUCT
504 obj->print_on(out);
505 #endif // PRODUCT
506 }
507 };
508
509 class VerifyLiveClosure : public G1VerificationClosure {
510 public:
511 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
512 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
513 virtual void do_oop(oop* p) { do_oop_work(p); }
514
515 template <class T>
516 void do_oop_work(T* p) {
517 assert(_containing_obj != NULL, "Precondition");
518 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
519 "Precondition");
520 verify_liveness(p);
521 }
522
523 template <class T>
524 void verify_liveness(T* p) {
525 T heap_oop = oopDesc::load_heap_oop(p);
526 Log(gc, verify) log;
527 if (!oopDesc::is_null(heap_oop)) {
528 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
529 bool failed = false;
530 if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
531 MutexLockerEx x(ParGCRareEvent_lock,
532 Mutex::_no_safepoint_check_flag);
533
534 if (!_failures) {
535 log.error("----------");
536 }
537 ResourceMark rm;
538 if (!_g1h->is_in_closed_subset(obj)) {
539 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
540 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
541 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end()));
542 LogStream ls(log.error());
543 print_object(&ls, _containing_obj);
544 log.error("points to obj " PTR_FORMAT " not in the heap", p2i(obj));
545 } else {
546 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
547 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
548 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
549 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end()));
550 LogStream ls(log.error());
551 print_object(&ls, _containing_obj);
552 log.error("points to dead obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")",
553 p2i(obj), p2i(to->bottom()), p2i(to->end()));
554 print_object(&ls, obj);
555 }
556 log.error("----------");
557 _failures = true;
558 failed = true;
559 _n_failures++;
560 }
561 }
562 }
563 };
564
565 class VerifyRemSetClosure : public G1VerificationClosure {
566 public:
567 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
568 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
569 virtual void do_oop(oop* p) { do_oop_work(p); }
570
571 template <class T>
572 void do_oop_work(T* p) {
573 assert(_containing_obj != NULL, "Precondition");
574 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
575 "Precondition");
576 verify_remembered_set(p);
577 }
578
579 template <class T>
580 void verify_remembered_set(T* p) {
581 T heap_oop = oopDesc::load_heap_oop(p);
582 Log(gc, verify) log;
583 if (!oopDesc::is_null(heap_oop)) {
584 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
585 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
586 HeapRegion* to = _g1h->heap_region_containing(obj);
587 if (from != NULL && to != NULL &&
588 from != to &&
589 !to->is_pinned()) {
590 jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
591 jbyte cv_field = *_bs->byte_for_const(p);
592 const jbyte dirty = CardTableModRefBS::dirty_card_val();
593
594 bool is_bad = !(from->is_young()
595 || to->rem_set()->contains_reference(p)
596 || (_containing_obj->is_objArray() ?
597 cv_field == dirty :
598 cv_obj == dirty || cv_field == dirty));
599 if (is_bad) {
600 MutexLockerEx x(ParGCRareEvent_lock,
601 Mutex::_no_safepoint_check_flag);
602
603 if (!_failures) {
604 log.error("----------");
605 }
606 log.error("Missing rem set entry:");
607 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT ", in region " HR_FORMAT,
608 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
609 ResourceMark rm;
610 LogStream ls(log.error());
611 _containing_obj->print_on(&ls);
612 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT, p2i(obj), HR_FORMAT_PARAMS(to));
613 if (obj->is_oop()) {
614 obj->print_on(&ls);
615 }
616 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
617 log.error("----------");
618 _failures = true;
619 _n_failures++;
620 }
621 }
622 }
623 }
624 };
625
626 // Closure that applies the given two closures in sequence.
627 class G1Mux2Closure : public OopClosure {
628 OopClosure* _c1;
629 OopClosure* _c2;
630 public:
631 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
632 template <class T> inline void do_oop_work(T* p) {
633 // Apply first closure; then apply the second.
634 _c1->do_oop(p);
635 _c2->do_oop(p);
636 }
637 virtual inline void do_oop(oop* p) { do_oop_work(p); }
638 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
639 };
640
641 // This really ought to be commoned up into OffsetTableContigSpace somehow.
642 // We would need a mechanism to make that code skip dead objects.
643
644 void HeapRegion::verify(VerifyOption vo,
645 bool* failures) const {
646 G1CollectedHeap* g1 = G1CollectedHeap::heap();
647 *failures = false;
648 HeapWord* p = bottom();
649 HeapWord* prev_p = NULL;
650 VerifyLiveClosure vl_cl(g1, vo);
651 VerifyRemSetClosure vr_cl(g1, vo);
652 bool is_region_humongous = is_humongous();
653 size_t object_num = 0;
654 while (p < top()) {
655 oop obj = oop(p);
656 size_t obj_size = block_size(p);
657 object_num += 1;
658
659 if (!g1->is_obj_dead_cond(obj, this, vo)) {
660 if (obj->is_oop()) {
661 Klass* klass = obj->klass();
662 bool is_metaspace_object = Metaspace::contains(klass) ||
663 (vo == VerifyOption_G1UsePrevMarking &&
664 ClassLoaderDataGraph::unload_list_contains(klass));
665 if (!is_metaspace_object) {
666 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
667 "not metadata", p2i(klass), p2i(obj));
668 *failures = true;
669 return;
670 } else if (!klass->is_klass()) {
671 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
672 "not a klass", p2i(klass), p2i(obj));
673 *failures = true;
674 return;
675 } else {
676 vl_cl.set_containing_obj(obj);
677 if (!g1->collector_state()->full_collection() || G1VerifyRSetsDuringFullGC) {
678 // verify liveness and rem_set
679 vr_cl.set_containing_obj(obj);
680 G1Mux2Closure mux(&vl_cl, &vr_cl);
681 obj->oop_iterate_no_header(&mux);
682
683 if (vr_cl.failures()) {
684 *failures = true;
685 }
686 if (G1MaxVerifyFailures >= 0 &&
687 vr_cl.n_failures() >= G1MaxVerifyFailures) {
688 return;
689 }
690 } else {
691 // verify only liveness
692 obj->oop_iterate_no_header(&vl_cl);
693 }
694 if (vl_cl.failures()) {
695 *failures = true;
696 }
697 if (G1MaxVerifyFailures >= 0 &&
698 vl_cl.n_failures() >= G1MaxVerifyFailures) {
699 return;
700 }
701 }
702 } else {
703 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
704 *failures = true;
705 return;
706 }
707 }
708 prev_p = p;
709 p += obj_size;
710 }
711
712 if (!is_young() && !is_empty()) {
713 _bot_part.verify();
714 }
715
716 if (is_region_humongous) {
717 oop obj = oop(this->humongous_start_region()->bottom());
718 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) {
719 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
720 *failures = true;
721 return;
722 }
723 }
724
725 if (!is_region_humongous && p != top()) {
726 log_error(gc, verify)("end of last object " PTR_FORMAT " "
727 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
728 *failures = true;
729 return;
730 }
731
732 HeapWord* the_end = end();
733 // Do some extra BOT consistency checking for addresses in the
734 // range [top, end). BOT look-ups in this range should yield
735 // top. No point in doing that if top == end (there's nothing there).
736 if (p < the_end) {
737 // Look up top
738 HeapWord* addr_1 = p;
739 HeapWord* b_start_1 = _bot_part.block_start_const(addr_1);
740 if (b_start_1 != p) {
741 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
742 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
743 p2i(addr_1), p2i(b_start_1), p2i(p));
744 *failures = true;
745 return;
746 }
747
748 // Look up top + 1
749 HeapWord* addr_2 = p + 1;
750 if (addr_2 < the_end) {
751 HeapWord* b_start_2 = _bot_part.block_start_const(addr_2);
752 if (b_start_2 != p) {
753 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
754 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
755 p2i(addr_2), p2i(b_start_2), p2i(p));
756 *failures = true;
757 return;
758 }
759 }
760
761 // Look up an address between top and end
762 size_t diff = pointer_delta(the_end, p) / 2;
763 HeapWord* addr_3 = p + diff;
764 if (addr_3 < the_end) {
765 HeapWord* b_start_3 = _bot_part.block_start_const(addr_3);
766 if (b_start_3 != p) {
767 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
768 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
769 p2i(addr_3), p2i(b_start_3), p2i(p));
770 *failures = true;
771 return;
772 }
773 }
774
775 // Look up end - 1
776 HeapWord* addr_4 = the_end - 1;
777 HeapWord* b_start_4 = _bot_part.block_start_const(addr_4);
778 if (b_start_4 != p) {
779 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
780 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
781 p2i(addr_4), p2i(b_start_4), p2i(p));
782 *failures = true;
783 return;
784 }
785 }
786
787 verify_strong_code_roots(vo, failures);
788 }
789
790 void HeapRegion::verify() const {
791 bool dummy = false;
792 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
793 }
794
795 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
796 G1CollectedHeap* g1 = G1CollectedHeap::heap();
797 *failures = false;
798 HeapWord* p = bottom();
799 HeapWord* prev_p = NULL;
800 VerifyRemSetClosure vr_cl(g1, vo);
801 while (p < top()) {
802 oop obj = oop(p);
803 size_t obj_size = block_size(p);
804
805 if (!g1->is_obj_dead_cond(obj, this, vo)) {
806 if (obj->is_oop()) {
807 vr_cl.set_containing_obj(obj);
808 obj->oop_iterate_no_header(&vr_cl);
809
810 if (vr_cl.failures()) {
811 *failures = true;
812 }
813 if (G1MaxVerifyFailures >= 0 &&
814 vr_cl.n_failures() >= G1MaxVerifyFailures) {
815 return;
816 }
817 } else {
818 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
819 *failures = true;
820 return;
821 }
822 }
823
824 prev_p = p;
825 p += obj_size;
826 }
827 }
828
829 void HeapRegion::verify_rem_set() const {
830 bool failures = false;
831 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
832 guarantee(!failures, "HeapRegion RemSet verification failed");
833 }
834
835 void HeapRegion::prepare_for_compaction(CompactPoint* cp) {
836 scan_and_forward(this, cp);
837 }
838
839 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
840 // away eventually.
841
842 void G1ContiguousSpace::clear(bool mangle_space) {
843 set_top(bottom());
844 CompactibleSpace::clear(mangle_space);
845 reset_bot();
846 }
847
848 #ifndef PRODUCT
849 void G1ContiguousSpace::mangle_unused_area() {
850 mangle_unused_area_complete();
851 }
852
853 void G1ContiguousSpace::mangle_unused_area_complete() {
854 SpaceMangler::mangle_region(MemRegion(top(), end()));
855 }
856 #endif
857
858 void G1ContiguousSpace::print() const {
859 print_short();
860 tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
861 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
862 p2i(bottom()), p2i(top()), p2i(_bot_part.threshold()), p2i(end()));
863 }
864
865 HeapWord* G1ContiguousSpace::initialize_threshold() {
866 return _bot_part.initialize_threshold();
867 }
868
869 HeapWord* G1ContiguousSpace::cross_threshold(HeapWord* start,
870 HeapWord* end) {
871 _bot_part.alloc_block(start, end);
872 return _bot_part.threshold();
873 }
874
875 void G1ContiguousSpace::record_timestamp() {
876 G1CollectedHeap* g1h = G1CollectedHeap::heap();
877 uint curr_gc_time_stamp = g1h->get_gc_time_stamp();
878
879 if (_gc_time_stamp < curr_gc_time_stamp) {
880 _gc_time_stamp = curr_gc_time_stamp;
881 }
882 }
883
884 void G1ContiguousSpace::safe_object_iterate(ObjectClosure* blk) {
885 object_iterate(blk);
886 }
887
888 void G1ContiguousSpace::object_iterate(ObjectClosure* blk) {
889 HeapWord* p = bottom();
890 while (p < top()) {
891 if (block_is_obj(p)) {
892 blk->do_object(oop(p));
893 }
894 p += block_size(p);
895 }
896 }
897
898 G1ContiguousSpace::G1ContiguousSpace(G1BlockOffsetTable* bot) :
899 _bot_part(bot, this),
900 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
901 _gc_time_stamp(0)
902 {
903 }
904
905 void G1ContiguousSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
906 CompactibleSpace::initialize(mr, clear_space, mangle_space);
907 _top = bottom();
908 set_saved_mark_word(NULL);
909 reset_bot();
910 }