comparison src/share/vm/gc_implementation/g1/heapRegion.hpp @ 362:f8199438385b

Merge
author apetrusenko
date Wed, 17 Sep 2008 16:49:18 +0400
parents 1ee8caae33af
children cc68c8e9b309
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316:5fa96a5a7e76 362:f8199438385b
1 /*
2 * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #ifndef SERIALGC
26
27 // A HeapRegion is the smallest piece of a G1CollectedHeap that
28 // can be collected independently.
29
30 // NOTE: Although a HeapRegion is a Space, its
31 // Space::initDirtyCardClosure method must not be called.
32 // The problem is that the existence of this method breaks
33 // the independence of barrier sets from remembered sets.
34 // The solution is to remove this method from the definition
35 // of a Space.
36
37 class CompactibleSpace;
38 class ContiguousSpace;
39 class HeapRegionRemSet;
40 class HeapRegionRemSetIterator;
41 class HeapRegion;
42
43 // A dirty card to oop closure for heap regions. It
44 // knows how to get the G1 heap and how to use the bitmap
45 // in the concurrent marker used by G1 to filter remembered
46 // sets.
47
48 class HeapRegionDCTOC : public ContiguousSpaceDCTOC {
49 public:
50 // Specification of possible DirtyCardToOopClosure filtering.
51 enum FilterKind {
52 NoFilterKind,
53 IntoCSFilterKind,
54 OutOfRegionFilterKind
55 };
56
57 protected:
58 HeapRegion* _hr;
59 FilterKind _fk;
60 G1CollectedHeap* _g1;
61
62 void walk_mem_region_with_cl(MemRegion mr,
63 HeapWord* bottom, HeapWord* top,
64 OopClosure* cl);
65
66 // We don't specialize this for FilteringClosure; filtering is handled by
67 // the "FilterKind" mechanism. But we provide this to avoid a compiler
68 // warning.
69 void walk_mem_region_with_cl(MemRegion mr,
70 HeapWord* bottom, HeapWord* top,
71 FilteringClosure* cl) {
72 HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top,
73 (OopClosure*)cl);
74 }
75
76 // Get the actual top of the area on which the closure will
77 // operate, given where the top is assumed to be (the end of the
78 // memory region passed to do_MemRegion) and where the object
79 // at the top is assumed to start. For example, an object may
80 // start at the top but actually extend past the assumed top,
81 // in which case the top becomes the end of the object.
82 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) {
83 return ContiguousSpaceDCTOC::get_actual_top(top, top_obj);
84 }
85
86 // Walk the given memory region from bottom to (actual) top
87 // looking for objects and applying the oop closure (_cl) to
88 // them. The base implementation of this treats the area as
89 // blocks, where a block may or may not be an object. Sub-
90 // classes should override this to provide more accurate
91 // or possibly more efficient walking.
92 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) {
93 Filtering_DCTOC::walk_mem_region(mr, bottom, top);
94 }
95
96 public:
97 HeapRegionDCTOC(G1CollectedHeap* g1,
98 HeapRegion* hr, OopClosure* cl,
99 CardTableModRefBS::PrecisionStyle precision,
100 FilterKind fk);
101 };
102
103
104 // The complicating factor is that BlockOffsetTable diverged
105 // significantly, and we need functionality that is only in the G1 version.
106 // So I copied that code, which led to an alternate G1 version of
107 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could
108 // be reconciled, then G1OffsetTableContigSpace could go away.
109
110 // The idea behind time stamps is the following. Doing a save_marks on
111 // all regions at every GC pause is time consuming (if I remember
112 // well, 10ms or so). So, we would like to do that only for regions
113 // that are GC alloc regions. To achieve this, we use time
114 // stamps. For every evacuation pause, G1CollectedHeap generates a
115 // unique time stamp (essentially a counter that gets
116 // incremented). Every time we want to call save_marks on a region,
117 // we set the saved_mark_word to top and also copy the current GC
118 // time stamp to the time stamp field of the space. Reading the
119 // saved_mark_word involves checking the time stamp of the
120 // region. If it is the same as the current GC time stamp, then we
121 // can safely read the saved_mark_word field, as it is valid. If the
122 // time stamp of the region is not the same as the current GC time
123 // stamp, then we instead read top, as the saved_mark_word field is
124 // invalid. Time stamps (on the regions and also on the
125 // G1CollectedHeap) are reset at every cleanup (we iterate over
126 // the regions anyway) and at the end of a Full GC. The current scheme
127 // that uses sequential unsigned ints will fail only if we have 4b
128 // evacuation pauses between two cleanups, which is _highly_ unlikely.
129
130 class G1OffsetTableContigSpace: public ContiguousSpace {
131 friend class VMStructs;
132 protected:
133 G1BlockOffsetArrayContigSpace _offsets;
134 Mutex _par_alloc_lock;
135 volatile unsigned _gc_time_stamp;
136
137 public:
138 // Constructor. If "is_zeroed" is true, the MemRegion "mr" may be
139 // assumed to contain zeros.
140 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
141 MemRegion mr, bool is_zeroed = false);
142
143 void set_bottom(HeapWord* value);
144 void set_end(HeapWord* value);
145
146 virtual HeapWord* saved_mark_word() const;
147 virtual void set_saved_mark();
148 void reset_gc_time_stamp() { _gc_time_stamp = 0; }
149
150 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);
151 virtual void clear(bool mangle_space);
152
153 HeapWord* block_start(const void* p);
154 HeapWord* block_start_const(const void* p) const;
155
156 // Add offset table update.
157 virtual HeapWord* allocate(size_t word_size);
158 HeapWord* par_allocate(size_t word_size);
159
160 // MarkSweep support phase3
161 virtual HeapWord* initialize_threshold();
162 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
163
164 virtual void print() const;
165 };
166
167 class HeapRegion: public G1OffsetTableContigSpace {
168 friend class VMStructs;
169 private:
170
171 enum HumongousType {
172 NotHumongous = 0,
173 StartsHumongous,
174 ContinuesHumongous
175 };
176
177 // The next filter kind that should be used for a "new_dcto_cl" call with
178 // the "traditional" signature.
179 HeapRegionDCTOC::FilterKind _next_fk;
180
181 // Requires that the region "mr" be dense with objects, and begin and end
182 // with an object.
183 void oops_in_mr_iterate(MemRegion mr, OopClosure* cl);
184
185 // The remembered set for this region.
186 // (Might want to make this "inline" later, to avoid some alloc failure
187 // issues.)
188 HeapRegionRemSet* _rem_set;
189
190 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; }
191
192 protected:
193 // If this region is a member of a HeapRegionSeq, the index in that
194 // sequence, otherwise -1.
195 int _hrs_index;
196
197 HumongousType _humongous_type;
198 // For a humongous region, region in which it starts.
199 HeapRegion* _humongous_start_region;
200 // For the start region of a humongous sequence, it's original end().
201 HeapWord* _orig_end;
202
203 // True iff the region is in current collection_set.
204 bool _in_collection_set;
205
206 // True iff the region is on the unclean list, waiting to be zero filled.
207 bool _is_on_unclean_list;
208
209 // True iff the region is on the free list, ready for allocation.
210 bool _is_on_free_list;
211
212 // Is this or has it been an allocation region in the current collection
213 // pause.
214 bool _is_gc_alloc_region;
215
216 // True iff an attempt to evacuate an object in the region failed.
217 bool _evacuation_failed;
218
219 // A heap region may be a member one of a number of special subsets, each
220 // represented as linked lists through the field below. Currently, these
221 // sets include:
222 // The collection set.
223 // The set of allocation regions used in a collection pause.
224 // Spaces that may contain gray objects.
225 HeapRegion* _next_in_special_set;
226
227 // next region in the young "generation" region set
228 HeapRegion* _next_young_region;
229
230 // For parallel heapRegion traversal.
231 jint _claimed;
232
233 // We use concurrent marking to determine the amount of live data
234 // in each heap region.
235 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking.
236 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking.
237
238 // See "sort_index" method. -1 means is not in the array.
239 int _sort_index;
240
241 // Means it has (or at least had) a very large RS, and should not be
242 // considered for membership in a collection set.
243 enum PopularityState {
244 NotPopular,
245 PopularPending,
246 Popular
247 };
248 PopularityState _popularity;
249
250 // <PREDICTION>
251 double _gc_efficiency;
252 // </PREDICTION>
253
254 enum YoungType {
255 NotYoung, // a region is not young
256 ScanOnly, // a region is young and scan-only
257 Young, // a region is young
258 Survivor // a region is young and it contains
259 // survivor
260 };
261
262 YoungType _young_type;
263 int _young_index_in_cset;
264 SurvRateGroup* _surv_rate_group;
265 int _age_index;
266
267 // The start of the unmarked area. The unmarked area extends from this
268 // word until the top and/or end of the region, and is the part
269 // of the region for which no marking was done, i.e. objects may
270 // have been allocated in this part since the last mark phase.
271 // "prev" is the top at the start of the last completed marking.
272 // "next" is the top at the start of the in-progress marking (if any.)
273 HeapWord* _prev_top_at_mark_start;
274 HeapWord* _next_top_at_mark_start;
275 // If a collection pause is in progress, this is the top at the start
276 // of that pause.
277
278 // We've counted the marked bytes of objects below here.
279 HeapWord* _top_at_conc_mark_count;
280
281 void init_top_at_mark_start() {
282 assert(_prev_marked_bytes == 0 &&
283 _next_marked_bytes == 0,
284 "Must be called after zero_marked_bytes.");
285 HeapWord* bot = bottom();
286 _prev_top_at_mark_start = bot;
287 _next_top_at_mark_start = bot;
288 _top_at_conc_mark_count = bot;
289 }
290
291 jint _zfs; // A member of ZeroFillState. Protected by ZF_lock.
292 Thread* _zero_filler; // If _zfs is ZeroFilling, the thread that (last)
293 // made it so.
294
295 void set_young_type(YoungType new_type) {
296 //assert(_young_type != new_type, "setting the same type" );
297 // TODO: add more assertions here
298 _young_type = new_type;
299 }
300
301 public:
302 // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
303 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
304 MemRegion mr, bool is_zeroed);
305
306 enum SomePublicConstants {
307 // HeapRegions are GrainBytes-aligned
308 // and have sizes that are multiples of GrainBytes.
309 LogOfHRGrainBytes = 20,
310 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize,
311 GrainBytes = 1 << LogOfHRGrainBytes,
312 GrainWords = 1 <<LogOfHRGrainWords,
313 MaxAge = 2, NoOfAges = MaxAge+1
314 };
315
316 enum ClaimValues {
317 InitialClaimValue = 0,
318 FinalCountClaimValue = 1,
319 NoteEndClaimValue = 2,
320 ScrubRemSetClaimValue = 3
321 };
322
323 // Concurrent refinement requires contiguous heap regions (in which TLABs
324 // might be allocated) to be zero-filled. Each region therefore has a
325 // zero-fill-state.
326 enum ZeroFillState {
327 NotZeroFilled,
328 ZeroFilling,
329 ZeroFilled,
330 Allocated
331 };
332
333 // If this region is a member of a HeapRegionSeq, the index in that
334 // sequence, otherwise -1.
335 int hrs_index() const { return _hrs_index; }
336 void set_hrs_index(int index) { _hrs_index = index; }
337
338 // The number of bytes marked live in the region in the last marking phase.
339 size_t marked_bytes() { return _prev_marked_bytes; }
340 // The number of bytes counted in the next marking.
341 size_t next_marked_bytes() { return _next_marked_bytes; }
342 // The number of bytes live wrt the next marking.
343 size_t next_live_bytes() {
344 return (top() - next_top_at_mark_start())
345 * HeapWordSize
346 + next_marked_bytes();
347 }
348
349 // A lower bound on the amount of garbage bytes in the region.
350 size_t garbage_bytes() {
351 size_t used_at_mark_start_bytes =
352 (prev_top_at_mark_start() - bottom()) * HeapWordSize;
353 assert(used_at_mark_start_bytes >= marked_bytes(),
354 "Can't mark more than we have.");
355 return used_at_mark_start_bytes - marked_bytes();
356 }
357
358 // An upper bound on the number of live bytes in the region.
359 size_t max_live_bytes() { return used() - garbage_bytes(); }
360
361 void add_to_marked_bytes(size_t incr_bytes) {
362 _next_marked_bytes = _next_marked_bytes + incr_bytes;
363 guarantee( _next_marked_bytes <= used(), "invariant" );
364 }
365
366 void zero_marked_bytes() {
367 _prev_marked_bytes = _next_marked_bytes = 0;
368 }
369
370 bool isHumongous() const { return _humongous_type != NotHumongous; }
371 bool startsHumongous() const { return _humongous_type == StartsHumongous; }
372 bool continuesHumongous() const { return _humongous_type == ContinuesHumongous; }
373 // For a humongous region, region in which it starts.
374 HeapRegion* humongous_start_region() const {
375 return _humongous_start_region;
376 }
377
378 // Causes the current region to represent a humongous object spanning "n"
379 // regions.
380 virtual void set_startsHumongous();
381
382 // The regions that continue a humongous sequence should be added using
383 // this method, in increasing address order.
384 void set_continuesHumongous(HeapRegion* start);
385
386 void add_continuingHumongousRegion(HeapRegion* cont);
387
388 // If the region has a remembered set, return a pointer to it.
389 HeapRegionRemSet* rem_set() const {
390 return _rem_set;
391 }
392
393 // True iff the region is in current collection_set.
394 bool in_collection_set() const {
395 return _in_collection_set;
396 }
397 void set_in_collection_set(bool b) {
398 _in_collection_set = b;
399 }
400 HeapRegion* next_in_collection_set() {
401 assert(in_collection_set(), "should only invoke on member of CS.");
402 assert(_next_in_special_set == NULL ||
403 _next_in_special_set->in_collection_set(),
404 "Malformed CS.");
405 return _next_in_special_set;
406 }
407 void set_next_in_collection_set(HeapRegion* r) {
408 assert(in_collection_set(), "should only invoke on member of CS.");
409 assert(r == NULL || r->in_collection_set(), "Malformed CS.");
410 _next_in_special_set = r;
411 }
412
413 // True iff it is or has been an allocation region in the current
414 // collection pause.
415 bool is_gc_alloc_region() const {
416 return _is_gc_alloc_region;
417 }
418 void set_is_gc_alloc_region(bool b) {
419 _is_gc_alloc_region = b;
420 }
421 HeapRegion* next_gc_alloc_region() {
422 assert(is_gc_alloc_region(), "should only invoke on member of CS.");
423 assert(_next_in_special_set == NULL ||
424 _next_in_special_set->is_gc_alloc_region(),
425 "Malformed CS.");
426 return _next_in_special_set;
427 }
428 void set_next_gc_alloc_region(HeapRegion* r) {
429 assert(is_gc_alloc_region(), "should only invoke on member of CS.");
430 assert(r == NULL || r->is_gc_alloc_region(), "Malformed CS.");
431 _next_in_special_set = r;
432 }
433
434 bool is_reserved() {
435 return popular();
436 }
437
438 bool is_on_free_list() {
439 return _is_on_free_list;
440 }
441
442 void set_on_free_list(bool b) {
443 _is_on_free_list = b;
444 }
445
446 HeapRegion* next_from_free_list() {
447 assert(is_on_free_list(),
448 "Should only invoke on free space.");
449 assert(_next_in_special_set == NULL ||
450 _next_in_special_set->is_on_free_list(),
451 "Malformed Free List.");
452 return _next_in_special_set;
453 }
454
455 void set_next_on_free_list(HeapRegion* r) {
456 assert(r == NULL || r->is_on_free_list(), "Malformed free list.");
457 _next_in_special_set = r;
458 }
459
460 bool is_on_unclean_list() {
461 return _is_on_unclean_list;
462 }
463
464 void set_on_unclean_list(bool b);
465
466 HeapRegion* next_from_unclean_list() {
467 assert(is_on_unclean_list(),
468 "Should only invoke on unclean space.");
469 assert(_next_in_special_set == NULL ||
470 _next_in_special_set->is_on_unclean_list(),
471 "Malformed unclean List.");
472 return _next_in_special_set;
473 }
474
475 void set_next_on_unclean_list(HeapRegion* r);
476
477 HeapRegion* get_next_young_region() { return _next_young_region; }
478 void set_next_young_region(HeapRegion* hr) {
479 _next_young_region = hr;
480 }
481
482 // Allows logical separation between objects allocated before and after.
483 void save_marks();
484
485 // Reset HR stuff to default values.
486 void hr_clear(bool par, bool clear_space);
487
488 void initialize(MemRegion mr, bool clear_space, bool mangle_space);
489
490 // Ensure that "this" is zero-filled.
491 void ensure_zero_filled();
492 // This one requires that the calling thread holds ZF_mon.
493 void ensure_zero_filled_locked();
494
495 // Get the start of the unmarked area in this region.
496 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }
497 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }
498
499 // Apply "cl->do_oop" to (the addresses of) all reference fields in objects
500 // allocated in the current region before the last call to "save_mark".
501 void oop_before_save_marks_iterate(OopClosure* cl);
502
503 // This call determines the "filter kind" argument that will be used for
504 // the next call to "new_dcto_cl" on this region with the "traditional"
505 // signature (i.e., the call below.) The default, in the absence of a
506 // preceding call to this method, is "NoFilterKind", and a call to this
507 // method is necessary for each such call, or else it reverts to the
508 // default.
509 // (This is really ugly, but all other methods I could think of changed a
510 // lot of main-line code for G1.)
511 void set_next_filter_kind(HeapRegionDCTOC::FilterKind nfk) {
512 _next_fk = nfk;
513 }
514
515 DirtyCardToOopClosure*
516 new_dcto_closure(OopClosure* cl,
517 CardTableModRefBS::PrecisionStyle precision,
518 HeapRegionDCTOC::FilterKind fk);
519
520 #if WHASSUP
521 DirtyCardToOopClosure*
522 new_dcto_closure(OopClosure* cl,
523 CardTableModRefBS::PrecisionStyle precision,
524 HeapWord* boundary) {
525 assert(boundary == NULL, "This arg doesn't make sense here.");
526 DirtyCardToOopClosure* res = new_dcto_closure(cl, precision, _next_fk);
527 _next_fk = HeapRegionDCTOC::NoFilterKind;
528 return res;
529 }
530 #endif
531
532 //
533 // Note the start or end of marking. This tells the heap region
534 // that the collector is about to start or has finished (concurrently)
535 // marking the heap.
536 //
537
538 // Note the start of a marking phase. Record the
539 // start of the unmarked area of the region here.
540 void note_start_of_marking(bool during_initial_mark) {
541 init_top_at_conc_mark_count();
542 _next_marked_bytes = 0;
543 if (during_initial_mark && is_young() && !is_survivor())
544 _next_top_at_mark_start = bottom();
545 else
546 _next_top_at_mark_start = top();
547 }
548
549 // Note the end of a marking phase. Install the start of
550 // the unmarked area that was captured at start of marking.
551 void note_end_of_marking() {
552 _prev_top_at_mark_start = _next_top_at_mark_start;
553 _prev_marked_bytes = _next_marked_bytes;
554 _next_marked_bytes = 0;
555
556 guarantee(_prev_marked_bytes <=
557 (size_t) (prev_top_at_mark_start() - bottom()) * HeapWordSize,
558 "invariant");
559 }
560
561 // After an evacuation, we need to update _next_top_at_mark_start
562 // to be the current top. Note this is only valid if we have only
563 // ever evacuated into this region. If we evacuate, allocate, and
564 // then evacuate we are in deep doodoo.
565 void note_end_of_copying() {
566 assert(top() >= _next_top_at_mark_start,
567 "Increase only");
568 _next_top_at_mark_start = top();
569 }
570
571 // Returns "false" iff no object in the region was allocated when the
572 // last mark phase ended.
573 bool is_marked() { return _prev_top_at_mark_start != bottom(); }
574
575 // If "is_marked()" is true, then this is the index of the region in
576 // an array constructed at the end of marking of the regions in a
577 // "desirability" order.
578 int sort_index() {
579 return _sort_index;
580 }
581 void set_sort_index(int i) {
582 _sort_index = i;
583 }
584
585 void init_top_at_conc_mark_count() {
586 _top_at_conc_mark_count = bottom();
587 }
588
589 void set_top_at_conc_mark_count(HeapWord *cur) {
590 assert(bottom() <= cur && cur <= end(), "Sanity.");
591 _top_at_conc_mark_count = cur;
592 }
593
594 HeapWord* top_at_conc_mark_count() {
595 return _top_at_conc_mark_count;
596 }
597
598 void reset_during_compaction() {
599 guarantee( isHumongous() && startsHumongous(),
600 "should only be called for humongous regions");
601
602 zero_marked_bytes();
603 init_top_at_mark_start();
604 }
605
606 bool popular() { return _popularity == Popular; }
607 void set_popular(bool b) {
608 if (b) {
609 _popularity = Popular;
610 } else {
611 _popularity = NotPopular;
612 }
613 }
614 bool popular_pending() { return _popularity == PopularPending; }
615 void set_popular_pending(bool b) {
616 if (b) {
617 _popularity = PopularPending;
618 } else {
619 _popularity = NotPopular;
620 }
621 }
622
623 // <PREDICTION>
624 void calc_gc_efficiency(void);
625 double gc_efficiency() { return _gc_efficiency;}
626 // </PREDICTION>
627
628 bool is_young() const { return _young_type != NotYoung; }
629 bool is_scan_only() const { return _young_type == ScanOnly; }
630 bool is_survivor() const { return _young_type == Survivor; }
631
632 int young_index_in_cset() const { return _young_index_in_cset; }
633 void set_young_index_in_cset(int index) {
634 assert( (index == -1) || is_young(), "pre-condition" );
635 _young_index_in_cset = index;
636 }
637
638 int age_in_surv_rate_group() {
639 assert( _surv_rate_group != NULL, "pre-condition" );
640 assert( _age_index > -1, "pre-condition" );
641 return _surv_rate_group->age_in_group(_age_index);
642 }
643
644 void recalculate_age_in_surv_rate_group() {
645 assert( _surv_rate_group != NULL, "pre-condition" );
646 assert( _age_index > -1, "pre-condition" );
647 _age_index = _surv_rate_group->recalculate_age_index(_age_index);
648 }
649
650 void record_surv_words_in_group(size_t words_survived) {
651 assert( _surv_rate_group != NULL, "pre-condition" );
652 assert( _age_index > -1, "pre-condition" );
653 int age_in_group = age_in_surv_rate_group();
654 _surv_rate_group->record_surviving_words(age_in_group, words_survived);
655 }
656
657 int age_in_surv_rate_group_cond() {
658 if (_surv_rate_group != NULL)
659 return age_in_surv_rate_group();
660 else
661 return -1;
662 }
663
664 SurvRateGroup* surv_rate_group() {
665 return _surv_rate_group;
666 }
667
668 void install_surv_rate_group(SurvRateGroup* surv_rate_group) {
669 assert( surv_rate_group != NULL, "pre-condition" );
670 assert( _surv_rate_group == NULL, "pre-condition" );
671 assert( is_young(), "pre-condition" );
672
673 _surv_rate_group = surv_rate_group;
674 _age_index = surv_rate_group->next_age_index();
675 }
676
677 void uninstall_surv_rate_group() {
678 if (_surv_rate_group != NULL) {
679 assert( _age_index > -1, "pre-condition" );
680 assert( is_young(), "pre-condition" );
681
682 _surv_rate_group = NULL;
683 _age_index = -1;
684 } else {
685 assert( _age_index == -1, "pre-condition" );
686 }
687 }
688
689 void set_young() { set_young_type(Young); }
690
691 void set_scan_only() { set_young_type(ScanOnly); }
692
693 void set_survivor() { set_young_type(Survivor); }
694
695 void set_not_young() { set_young_type(NotYoung); }
696
697 // Determine if an object has been allocated since the last
698 // mark performed by the collector. This returns true iff the object
699 // is within the unmarked area of the region.
700 bool obj_allocated_since_prev_marking(oop obj) const {
701 return (HeapWord *) obj >= prev_top_at_mark_start();
702 }
703 bool obj_allocated_since_next_marking(oop obj) const {
704 return (HeapWord *) obj >= next_top_at_mark_start();
705 }
706
707 // For parallel heapRegion traversal.
708 bool claimHeapRegion(int claimValue);
709 jint claim_value() { return _claimed; }
710 // Use this carefully: only when you're sure no one is claiming...
711 void set_claim_value(int claimValue) { _claimed = claimValue; }
712
713 // Returns the "evacuation_failed" property of the region.
714 bool evacuation_failed() { return _evacuation_failed; }
715
716 // Sets the "evacuation_failed" property of the region.
717 void set_evacuation_failed(bool b) {
718 _evacuation_failed = b;
719
720 if (b) {
721 init_top_at_conc_mark_count();
722 _next_marked_bytes = 0;
723 }
724 }
725
726 // Requires that "mr" be entirely within the region.
727 // Apply "cl->do_object" to all objects that intersect with "mr".
728 // If the iteration encounters an unparseable portion of the region,
729 // or if "cl->abort()" is true after a closure application,
730 // terminate the iteration and return the address of the start of the
731 // subregion that isn't done. (The two can be distinguished by querying
732 // "cl->abort()".) Return of "NULL" indicates that the iteration
733 // completed.
734 HeapWord*
735 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl);
736
737 HeapWord*
738 oops_on_card_seq_iterate_careful(MemRegion mr,
739 FilterOutOfRegionClosure* cl);
740
741 // The region "mr" is entirely in "this", and starts and ends at block
742 // boundaries. The caller declares that all the contained blocks are
743 // coalesced into one.
744 void declare_filled_region_to_BOT(MemRegion mr) {
745 _offsets.single_block(mr.start(), mr.end());
746 }
747
748 // A version of block start that is guaranteed to find *some* block
749 // boundary at or before "p", but does not object iteration, and may
750 // therefore be used safely when the heap is unparseable.
751 HeapWord* block_start_careful(const void* p) const {
752 return _offsets.block_start_careful(p);
753 }
754
755 // Requires that "addr" is within the region. Returns the start of the
756 // first ("careful") block that starts at or after "addr", or else the
757 // "end" of the region if there is no such block.
758 HeapWord* next_block_start_careful(HeapWord* addr);
759
760 // Returns the zero-fill-state of the current region.
761 ZeroFillState zero_fill_state() { return (ZeroFillState)_zfs; }
762 bool zero_fill_is_allocated() { return _zfs == Allocated; }
763 Thread* zero_filler() { return _zero_filler; }
764
765 // Indicate that the contents of the region are unknown, and therefore
766 // might require zero-filling.
767 void set_zero_fill_needed() {
768 set_zero_fill_state_work(NotZeroFilled);
769 }
770 void set_zero_fill_in_progress(Thread* t) {
771 set_zero_fill_state_work(ZeroFilling);
772 _zero_filler = t;
773 }
774 void set_zero_fill_complete();
775 void set_zero_fill_allocated() {
776 set_zero_fill_state_work(Allocated);
777 }
778
779 void set_zero_fill_state_work(ZeroFillState zfs);
780
781 // This is called when a full collection shrinks the heap.
782 // We want to set the heap region to a value which says
783 // it is no longer part of the heap. For now, we'll let "NotZF" fill
784 // that role.
785 void reset_zero_fill() {
786 set_zero_fill_state_work(NotZeroFilled);
787 _zero_filler = NULL;
788 }
789
790 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
791 virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
792 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
793
794 CompactibleSpace* next_compaction_space() const;
795
796 virtual void reset_after_compaction();
797
798 void print() const;
799 void print_on(outputStream* st) const;
800
801 // Override
802 virtual void verify(bool allow_dirty) const;
803
804 #ifdef DEBUG
805 HeapWord* allocate(size_t size);
806 #endif
807 };
808
809 // HeapRegionClosure is used for iterating over regions.
810 // Terminates the iteration when the "doHeapRegion" method returns "true".
811 class HeapRegionClosure : public StackObj {
812 friend class HeapRegionSeq;
813 friend class G1CollectedHeap;
814
815 bool _complete;
816 void incomplete() { _complete = false; }
817
818 public:
819 HeapRegionClosure(): _complete(true) {}
820
821 // Typically called on each region until it returns true.
822 virtual bool doHeapRegion(HeapRegion* r) = 0;
823
824 // True after iteration if the closure was applied to all heap regions
825 // and returned "false" in all cases.
826 bool complete() { return _complete; }
827 };
828
829 // A linked lists of heap regions. It leaves the "next" field
830 // unspecified; that's up to subtypes.
831 class RegionList {
832 protected:
833 virtual HeapRegion* get_next(HeapRegion* chr) = 0;
834 virtual void set_next(HeapRegion* chr,
835 HeapRegion* new_next) = 0;
836
837 HeapRegion* _hd;
838 HeapRegion* _tl;
839 size_t _sz;
840
841 // Protected constructor because this type is only meaningful
842 // when the _get/_set next functions are defined.
843 RegionList() : _hd(NULL), _tl(NULL), _sz(0) {}
844 public:
845 void reset() {
846 _hd = NULL;
847 _tl = NULL;
848 _sz = 0;
849 }
850 HeapRegion* hd() { return _hd; }
851 HeapRegion* tl() { return _tl; }
852 size_t sz() { return _sz; }
853 size_t length();
854
855 bool well_formed() {
856 return
857 ((hd() == NULL && tl() == NULL && sz() == 0)
858 || (hd() != NULL && tl() != NULL && sz() > 0))
859 && (sz() == length());
860 }
861 virtual void insert_before_head(HeapRegion* r);
862 void prepend_list(RegionList* new_list);
863 virtual HeapRegion* pop();
864 void dec_sz() { _sz--; }
865 // Requires that "r" is an element of the list, and is not the tail.
866 void delete_after(HeapRegion* r);
867 };
868
869 class EmptyNonHRegionList: public RegionList {
870 protected:
871 // Protected constructor because this type is only meaningful
872 // when the _get/_set next functions are defined.
873 EmptyNonHRegionList() : RegionList() {}
874
875 public:
876 void insert_before_head(HeapRegion* r) {
877 // assert(r->is_empty(), "Better be empty");
878 assert(!r->isHumongous(), "Better not be humongous.");
879 RegionList::insert_before_head(r);
880 }
881 void prepend_list(EmptyNonHRegionList* new_list) {
882 // assert(new_list->hd() == NULL || new_list->hd()->is_empty(),
883 // "Better be empty");
884 assert(new_list->hd() == NULL || !new_list->hd()->isHumongous(),
885 "Better not be humongous.");
886 // assert(new_list->tl() == NULL || new_list->tl()->is_empty(),
887 // "Better be empty");
888 assert(new_list->tl() == NULL || !new_list->tl()->isHumongous(),
889 "Better not be humongous.");
890 RegionList::prepend_list(new_list);
891 }
892 };
893
894 class UncleanRegionList: public EmptyNonHRegionList {
895 public:
896 HeapRegion* get_next(HeapRegion* hr) {
897 return hr->next_from_unclean_list();
898 }
899 void set_next(HeapRegion* hr, HeapRegion* new_next) {
900 hr->set_next_on_unclean_list(new_next);
901 }
902
903 UncleanRegionList() : EmptyNonHRegionList() {}
904
905 void insert_before_head(HeapRegion* r) {
906 assert(!r->is_on_free_list(),
907 "Better not already be on free list");
908 assert(!r->is_on_unclean_list(),
909 "Better not already be on unclean list");
910 r->set_zero_fill_needed();
911 r->set_on_unclean_list(true);
912 EmptyNonHRegionList::insert_before_head(r);
913 }
914 void prepend_list(UncleanRegionList* new_list) {
915 assert(new_list->tl() == NULL || !new_list->tl()->is_on_free_list(),
916 "Better not already be on free list");
917 assert(new_list->tl() == NULL || new_list->tl()->is_on_unclean_list(),
918 "Better already be marked as on unclean list");
919 assert(new_list->hd() == NULL || !new_list->hd()->is_on_free_list(),
920 "Better not already be on free list");
921 assert(new_list->hd() == NULL || new_list->hd()->is_on_unclean_list(),
922 "Better already be marked as on unclean list");
923 EmptyNonHRegionList::prepend_list(new_list);
924 }
925 HeapRegion* pop() {
926 HeapRegion* res = RegionList::pop();
927 if (res != NULL) res->set_on_unclean_list(false);
928 return res;
929 }
930 };
931
932 // Local Variables: ***
933 // c-indentation-style: gnu ***
934 // End: ***
935
936 #endif // SERIALGC