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rev 2896 : 6484965: G1: piggy-back liveness accounting phase on marking
Summary: Remove the separate counting phase of concurrent marking by tracking the amount of marked bytes and the cards spanned by marked objects in marking task/worker thread local data structures, which are updated as individual objects are marked.
Reviewed-by: brutisso
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--- old/src/share/vm/gc_implementation/g1/heapRegion.hpp
+++ new/src/share/vm/gc_implementation/g1/heapRegion.hpp
1 1 /*
2 2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 20 * or visit www.oracle.com if you need additional information or have any
21 21 * questions.
22 22 *
23 23 */
24 24
25 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP
26 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP
27 27
28 28 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
29 29 #include "gc_implementation/g1/g1_specialized_oop_closures.hpp"
30 30 #include "gc_implementation/g1/survRateGroup.hpp"
31 31 #include "gc_implementation/shared/ageTable.hpp"
32 32 #include "gc_implementation/shared/spaceDecorator.hpp"
33 33 #include "memory/space.inline.hpp"
34 34 #include "memory/watermark.hpp"
35 35
36 36 #ifndef SERIALGC
37 37
38 38 // A HeapRegion is the smallest piece of a G1CollectedHeap that
39 39 // can be collected independently.
40 40
41 41 // NOTE: Although a HeapRegion is a Space, its
42 42 // Space::initDirtyCardClosure method must not be called.
43 43 // The problem is that the existence of this method breaks
44 44 // the independence of barrier sets from remembered sets.
45 45 // The solution is to remove this method from the definition
46 46 // of a Space.
47 47
48 48 class CompactibleSpace;
49 49 class ContiguousSpace;
50 50 class HeapRegionRemSet;
51 51 class HeapRegionRemSetIterator;
52 52 class HeapRegion;
53 53 class HeapRegionSetBase;
54 54
55 55 #define HR_FORMAT SIZE_FORMAT":(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]"
56 56 #define HR_FORMAT_PARAMS(_hr_) \
57 57 (_hr_)->hrs_index(), \
58 58 (_hr_)->is_survivor() ? "S" : (_hr_)->is_young() ? "E" : "-", \
59 59 (_hr_)->bottom(), (_hr_)->top(), (_hr_)->end()
60 60
61 61 // A dirty card to oop closure for heap regions. It
62 62 // knows how to get the G1 heap and how to use the bitmap
63 63 // in the concurrent marker used by G1 to filter remembered
64 64 // sets.
65 65
66 66 class HeapRegionDCTOC : public ContiguousSpaceDCTOC {
67 67 public:
68 68 // Specification of possible DirtyCardToOopClosure filtering.
69 69 enum FilterKind {
70 70 NoFilterKind,
71 71 IntoCSFilterKind,
72 72 OutOfRegionFilterKind
73 73 };
74 74
75 75 protected:
76 76 HeapRegion* _hr;
77 77 FilterKind _fk;
78 78 G1CollectedHeap* _g1;
79 79
80 80 void walk_mem_region_with_cl(MemRegion mr,
81 81 HeapWord* bottom, HeapWord* top,
82 82 OopClosure* cl);
83 83
84 84 // We don't specialize this for FilteringClosure; filtering is handled by
85 85 // the "FilterKind" mechanism. But we provide this to avoid a compiler
86 86 // warning.
87 87 void walk_mem_region_with_cl(MemRegion mr,
88 88 HeapWord* bottom, HeapWord* top,
89 89 FilteringClosure* cl) {
90 90 HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top,
91 91 (OopClosure*)cl);
92 92 }
93 93
94 94 // Get the actual top of the area on which the closure will
95 95 // operate, given where the top is assumed to be (the end of the
96 96 // memory region passed to do_MemRegion) and where the object
97 97 // at the top is assumed to start. For example, an object may
98 98 // start at the top but actually extend past the assumed top,
99 99 // in which case the top becomes the end of the object.
100 100 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) {
101 101 return ContiguousSpaceDCTOC::get_actual_top(top, top_obj);
102 102 }
103 103
104 104 // Walk the given memory region from bottom to (actual) top
105 105 // looking for objects and applying the oop closure (_cl) to
106 106 // them. The base implementation of this treats the area as
107 107 // blocks, where a block may or may not be an object. Sub-
108 108 // classes should override this to provide more accurate
109 109 // or possibly more efficient walking.
110 110 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) {
111 111 Filtering_DCTOC::walk_mem_region(mr, bottom, top);
112 112 }
113 113
114 114 public:
115 115 HeapRegionDCTOC(G1CollectedHeap* g1,
116 116 HeapRegion* hr, OopClosure* cl,
117 117 CardTableModRefBS::PrecisionStyle precision,
118 118 FilterKind fk);
119 119 };
120 120
121 121 // The complicating factor is that BlockOffsetTable diverged
122 122 // significantly, and we need functionality that is only in the G1 version.
123 123 // So I copied that code, which led to an alternate G1 version of
124 124 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could
125 125 // be reconciled, then G1OffsetTableContigSpace could go away.
126 126
127 127 // The idea behind time stamps is the following. Doing a save_marks on
128 128 // all regions at every GC pause is time consuming (if I remember
129 129 // well, 10ms or so). So, we would like to do that only for regions
130 130 // that are GC alloc regions. To achieve this, we use time
131 131 // stamps. For every evacuation pause, G1CollectedHeap generates a
132 132 // unique time stamp (essentially a counter that gets
133 133 // incremented). Every time we want to call save_marks on a region,
134 134 // we set the saved_mark_word to top and also copy the current GC
135 135 // time stamp to the time stamp field of the space. Reading the
136 136 // saved_mark_word involves checking the time stamp of the
137 137 // region. If it is the same as the current GC time stamp, then we
138 138 // can safely read the saved_mark_word field, as it is valid. If the
139 139 // time stamp of the region is not the same as the current GC time
140 140 // stamp, then we instead read top, as the saved_mark_word field is
141 141 // invalid. Time stamps (on the regions and also on the
142 142 // G1CollectedHeap) are reset at every cleanup (we iterate over
143 143 // the regions anyway) and at the end of a Full GC. The current scheme
144 144 // that uses sequential unsigned ints will fail only if we have 4b
145 145 // evacuation pauses between two cleanups, which is _highly_ unlikely.
146 146
147 147 class G1OffsetTableContigSpace: public ContiguousSpace {
148 148 friend class VMStructs;
149 149 protected:
150 150 G1BlockOffsetArrayContigSpace _offsets;
151 151 Mutex _par_alloc_lock;
152 152 volatile unsigned _gc_time_stamp;
153 153 // When we need to retire an allocation region, while other threads
154 154 // are also concurrently trying to allocate into it, we typically
155 155 // allocate a dummy object at the end of the region to ensure that
156 156 // no more allocations can take place in it. However, sometimes we
157 157 // want to know where the end of the last "real" object we allocated
158 158 // into the region was and this is what this keeps track.
159 159 HeapWord* _pre_dummy_top;
160 160
161 161 public:
162 162 // Constructor. If "is_zeroed" is true, the MemRegion "mr" may be
163 163 // assumed to contain zeros.
164 164 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
165 165 MemRegion mr, bool is_zeroed = false);
166 166
167 167 void set_bottom(HeapWord* value);
168 168 void set_end(HeapWord* value);
169 169
170 170 virtual HeapWord* saved_mark_word() const;
171 171 virtual void set_saved_mark();
172 172 void reset_gc_time_stamp() { _gc_time_stamp = 0; }
173 173
174 174 // See the comment above in the declaration of _pre_dummy_top for an
175 175 // explanation of what it is.
176 176 void set_pre_dummy_top(HeapWord* pre_dummy_top) {
177 177 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition");
178 178 _pre_dummy_top = pre_dummy_top;
179 179 }
180 180 HeapWord* pre_dummy_top() {
181 181 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top;
182 182 }
183 183 void reset_pre_dummy_top() { _pre_dummy_top = NULL; }
184 184
185 185 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);
186 186 virtual void clear(bool mangle_space);
187 187
188 188 HeapWord* block_start(const void* p);
189 189 HeapWord* block_start_const(const void* p) const;
190 190
191 191 // Add offset table update.
192 192 virtual HeapWord* allocate(size_t word_size);
193 193 HeapWord* par_allocate(size_t word_size);
194 194
195 195 // MarkSweep support phase3
196 196 virtual HeapWord* initialize_threshold();
197 197 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
198 198
199 199 virtual void print() const;
200 200
201 201 void reset_bot() {
202 202 _offsets.zero_bottom_entry();
203 203 _offsets.initialize_threshold();
204 204 }
205 205
206 206 void update_bot_for_object(HeapWord* start, size_t word_size) {
207 207 _offsets.alloc_block(start, word_size);
208 208 }
209 209
210 210 void print_bot_on(outputStream* out) {
211 211 _offsets.print_on(out);
212 212 }
213 213 };
214 214
215 215 class HeapRegion: public G1OffsetTableContigSpace {
216 216 friend class VMStructs;
217 217 private:
218 218
219 219 enum HumongousType {
220 220 NotHumongous = 0,
221 221 StartsHumongous,
222 222 ContinuesHumongous
223 223 };
224 224
225 225 // Requires that the region "mr" be dense with objects, and begin and end
226 226 // with an object.
227 227 void oops_in_mr_iterate(MemRegion mr, OopClosure* cl);
228 228
229 229 // The remembered set for this region.
230 230 // (Might want to make this "inline" later, to avoid some alloc failure
231 231 // issues.)
232 232 HeapRegionRemSet* _rem_set;
233 233
234 234 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; }
235 235
236 236 protected:
237 237 // The index of this region in the heap region sequence.
238 238 size_t _hrs_index;
239 239
240 240 HumongousType _humongous_type;
241 241 // For a humongous region, region in which it starts.
242 242 HeapRegion* _humongous_start_region;
243 243 // For the start region of a humongous sequence, it's original end().
244 244 HeapWord* _orig_end;
245 245
246 246 // True iff the region is in current collection_set.
247 247 bool _in_collection_set;
248 248
249 249 // True iff an attempt to evacuate an object in the region failed.
250 250 bool _evacuation_failed;
251 251
252 252 // A heap region may be a member one of a number of special subsets, each
253 253 // represented as linked lists through the field below. Currently, these
254 254 // sets include:
255 255 // The collection set.
256 256 // The set of allocation regions used in a collection pause.
257 257 // Spaces that may contain gray objects.
258 258 HeapRegion* _next_in_special_set;
259 259
260 260 // next region in the young "generation" region set
261 261 HeapRegion* _next_young_region;
262 262
263 263 // Next region whose cards need cleaning
264 264 HeapRegion* _next_dirty_cards_region;
265 265
266 266 // Fields used by the HeapRegionSetBase class and subclasses.
267 267 HeapRegion* _next;
268 268 #ifdef ASSERT
269 269 HeapRegionSetBase* _containing_set;
270 270 #endif // ASSERT
271 271 bool _pending_removal;
272 272
273 273 // For parallel heapRegion traversal.
274 274 jint _claimed;
275 275
276 276 // We use concurrent marking to determine the amount of live data
277 277 // in each heap region.
278 278 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking.
279 279 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking.
280 280
281 281 // See "sort_index" method. -1 means is not in the array.
282 282 int _sort_index;
283 283
284 284 // <PREDICTION>
285 285 double _gc_efficiency;
286 286 // </PREDICTION>
287 287
288 288 enum YoungType {
289 289 NotYoung, // a region is not young
290 290 Young, // a region is young
291 291 Survivor // a region is young and it contains survivors
292 292 };
293 293
294 294 volatile YoungType _young_type;
295 295 int _young_index_in_cset;
296 296 SurvRateGroup* _surv_rate_group;
297 297 int _age_index;
298 298
299 299 // The start of the unmarked area. The unmarked area extends from this
300 300 // word until the top and/or end of the region, and is the part
301 301 // of the region for which no marking was done, i.e. objects may
302 302 // have been allocated in this part since the last mark phase.
303 303 // "prev" is the top at the start of the last completed marking.
304 304 // "next" is the top at the start of the in-progress marking (if any.)
305 305 HeapWord* _prev_top_at_mark_start;
306 306 HeapWord* _next_top_at_mark_start;
307 307 // If a collection pause is in progress, this is the top at the start
308 308 // of that pause.
309 309
310 310 // We've counted the marked bytes of objects below here.
311 311 HeapWord* _top_at_conc_mark_count;
312 312
313 313 void init_top_at_mark_start() {
314 314 assert(_prev_marked_bytes == 0 &&
315 315 _next_marked_bytes == 0,
316 316 "Must be called after zero_marked_bytes.");
317 317 HeapWord* bot = bottom();
318 318 _prev_top_at_mark_start = bot;
319 319 _next_top_at_mark_start = bot;
320 320 _top_at_conc_mark_count = bot;
321 321 }
322 322
323 323 void set_young_type(YoungType new_type) {
324 324 //assert(_young_type != new_type, "setting the same type" );
325 325 // TODO: add more assertions here
326 326 _young_type = new_type;
327 327 }
328 328
329 329 // Cached attributes used in the collection set policy information
330 330
331 331 // The RSet length that was added to the total value
332 332 // for the collection set.
333 333 size_t _recorded_rs_length;
334 334
335 335 // The predicted elapsed time that was added to total value
336 336 // for the collection set.
337 337 double _predicted_elapsed_time_ms;
338 338
339 339 // The predicted number of bytes to copy that was added to
340 340 // the total value for the collection set.
341 341 size_t _predicted_bytes_to_copy;
342 342
343 343 public:
344 344 // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
345 345 HeapRegion(size_t hrs_index,
346 346 G1BlockOffsetSharedArray* sharedOffsetArray,
347 347 MemRegion mr, bool is_zeroed);
348 348
349 349 static int LogOfHRGrainBytes;
350 350 static int LogOfHRGrainWords;
351 351
352 352 static size_t GrainBytes;
353 353 static size_t GrainWords;
354 354 static size_t CardsPerRegion;
355 355
356 356 static size_t align_up_to_region_byte_size(size_t sz) {
357 357 return (sz + (size_t) GrainBytes - 1) &
358 358 ~((1 << (size_t) LogOfHRGrainBytes) - 1);
359 359 }
360 360
361 361 // It sets up the heap region size (GrainBytes / GrainWords), as
362 362 // well as other related fields that are based on the heap region
363 363 // size (LogOfHRGrainBytes / LogOfHRGrainWords /
364 364 // CardsPerRegion). All those fields are considered constant
365 365 // throughout the JVM's execution, therefore they should only be set
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366 366 // up once during initialization time.
367 367 static void setup_heap_region_size(uintx min_heap_size);
368 368
369 369 enum ClaimValues {
370 370 InitialClaimValue = 0,
371 371 FinalCountClaimValue = 1,
372 372 NoteEndClaimValue = 2,
373 373 ScrubRemSetClaimValue = 3,
374 374 ParVerifyClaimValue = 4,
375 375 RebuildRSClaimValue = 5,
376 - CompleteMarkCSetClaimValue = 6
376 + CompleteMarkCSetClaimValue = 6,
377 + AggregateCountClaimValue = 7,
378 + VerifyCountClaimValue = 8
377 379 };
378 380
379 381 inline HeapWord* par_allocate_no_bot_updates(size_t word_size) {
380 382 assert(is_young(), "we can only skip BOT updates on young regions");
381 383 return ContiguousSpace::par_allocate(word_size);
382 384 }
383 385 inline HeapWord* allocate_no_bot_updates(size_t word_size) {
384 386 assert(is_young(), "we can only skip BOT updates on young regions");
385 387 return ContiguousSpace::allocate(word_size);
386 388 }
387 389
388 390 // If this region is a member of a HeapRegionSeq, the index in that
389 391 // sequence, otherwise -1.
390 392 size_t hrs_index() const { return _hrs_index; }
391 393
392 394 // The number of bytes marked live in the region in the last marking phase.
393 395 size_t marked_bytes() { return _prev_marked_bytes; }
394 396 size_t live_bytes() {
395 397 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes();
396 398 }
397 399
398 400 // The number of bytes counted in the next marking.
399 401 size_t next_marked_bytes() { return _next_marked_bytes; }
400 402 // The number of bytes live wrt the next marking.
401 403 size_t next_live_bytes() {
402 404 return
403 405 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes();
404 406 }
405 407
406 408 // A lower bound on the amount of garbage bytes in the region.
407 409 size_t garbage_bytes() {
408 410 size_t used_at_mark_start_bytes =
409 411 (prev_top_at_mark_start() - bottom()) * HeapWordSize;
410 412 assert(used_at_mark_start_bytes >= marked_bytes(),
411 413 "Can't mark more than we have.");
412 414 return used_at_mark_start_bytes - marked_bytes();
413 415 }
414 416
415 417 // An upper bound on the number of live bytes in the region.
416 418 size_t max_live_bytes() { return used() - garbage_bytes(); }
417 419
418 420 void add_to_marked_bytes(size_t incr_bytes) {
419 421 _next_marked_bytes = _next_marked_bytes + incr_bytes;
420 422 assert(_next_marked_bytes <= used(), "invariant" );
421 423 }
422 424
423 425 void zero_marked_bytes() {
424 426 _prev_marked_bytes = _next_marked_bytes = 0;
425 427 }
426 428
427 429 bool isHumongous() const { return _humongous_type != NotHumongous; }
428 430 bool startsHumongous() const { return _humongous_type == StartsHumongous; }
429 431 bool continuesHumongous() const { return _humongous_type == ContinuesHumongous; }
430 432 // For a humongous region, region in which it starts.
431 433 HeapRegion* humongous_start_region() const {
432 434 return _humongous_start_region;
433 435 }
434 436
435 437 // Same as Space::is_in_reserved, but will use the original size of the region.
436 438 // The original size is different only for start humongous regions. They get
437 439 // their _end set up to be the end of the last continues region of the
438 440 // corresponding humongous object.
439 441 bool is_in_reserved_raw(const void* p) const {
440 442 return _bottom <= p && p < _orig_end;
441 443 }
442 444
443 445 // Makes the current region be a "starts humongous" region, i.e.,
444 446 // the first region in a series of one or more contiguous regions
445 447 // that will contain a single "humongous" object. The two parameters
446 448 // are as follows:
447 449 //
448 450 // new_top : The new value of the top field of this region which
449 451 // points to the end of the humongous object that's being
450 452 // allocated. If there is more than one region in the series, top
451 453 // will lie beyond this region's original end field and on the last
452 454 // region in the series.
453 455 //
454 456 // new_end : The new value of the end field of this region which
455 457 // points to the end of the last region in the series. If there is
456 458 // one region in the series (namely: this one) end will be the same
457 459 // as the original end of this region.
458 460 //
459 461 // Updating top and end as described above makes this region look as
460 462 // if it spans the entire space taken up by all the regions in the
461 463 // series and an single allocation moved its top to new_top. This
462 464 // ensures that the space (capacity / allocated) taken up by all
463 465 // humongous regions can be calculated by just looking at the
464 466 // "starts humongous" regions and by ignoring the "continues
465 467 // humongous" regions.
466 468 void set_startsHumongous(HeapWord* new_top, HeapWord* new_end);
467 469
468 470 // Makes the current region be a "continues humongous'
469 471 // region. first_hr is the "start humongous" region of the series
470 472 // which this region will be part of.
471 473 void set_continuesHumongous(HeapRegion* first_hr);
472 474
473 475 // Unsets the humongous-related fields on the region.
474 476 void set_notHumongous();
475 477
476 478 // If the region has a remembered set, return a pointer to it.
477 479 HeapRegionRemSet* rem_set() const {
478 480 return _rem_set;
479 481 }
480 482
481 483 // True iff the region is in current collection_set.
482 484 bool in_collection_set() const {
483 485 return _in_collection_set;
484 486 }
485 487 void set_in_collection_set(bool b) {
486 488 _in_collection_set = b;
487 489 }
488 490 HeapRegion* next_in_collection_set() {
489 491 assert(in_collection_set(), "should only invoke on member of CS.");
490 492 assert(_next_in_special_set == NULL ||
491 493 _next_in_special_set->in_collection_set(),
492 494 "Malformed CS.");
493 495 return _next_in_special_set;
494 496 }
495 497 void set_next_in_collection_set(HeapRegion* r) {
496 498 assert(in_collection_set(), "should only invoke on member of CS.");
497 499 assert(r == NULL || r->in_collection_set(), "Malformed CS.");
498 500 _next_in_special_set = r;
499 501 }
500 502
501 503 // Methods used by the HeapRegionSetBase class and subclasses.
502 504
503 505 // Getter and setter for the next field used to link regions into
504 506 // linked lists.
505 507 HeapRegion* next() { return _next; }
506 508
507 509 void set_next(HeapRegion* next) { _next = next; }
508 510
509 511 // Every region added to a set is tagged with a reference to that
510 512 // set. This is used for doing consistency checking to make sure that
511 513 // the contents of a set are as they should be and it's only
512 514 // available in non-product builds.
513 515 #ifdef ASSERT
514 516 void set_containing_set(HeapRegionSetBase* containing_set) {
515 517 assert((containing_set == NULL && _containing_set != NULL) ||
516 518 (containing_set != NULL && _containing_set == NULL),
517 519 err_msg("containing_set: "PTR_FORMAT" "
518 520 "_containing_set: "PTR_FORMAT,
519 521 containing_set, _containing_set));
520 522
521 523 _containing_set = containing_set;
522 524 }
523 525
524 526 HeapRegionSetBase* containing_set() { return _containing_set; }
525 527 #else // ASSERT
526 528 void set_containing_set(HeapRegionSetBase* containing_set) { }
527 529
528 530 // containing_set() is only used in asserts so there's no reason
529 531 // to provide a dummy version of it.
530 532 #endif // ASSERT
531 533
532 534 // If we want to remove regions from a list in bulk we can simply tag
533 535 // them with the pending_removal tag and call the
534 536 // remove_all_pending() method on the list.
535 537
536 538 bool pending_removal() { return _pending_removal; }
537 539
538 540 void set_pending_removal(bool pending_removal) {
539 541 if (pending_removal) {
540 542 assert(!_pending_removal && containing_set() != NULL,
541 543 "can only set pending removal to true if it's false and "
542 544 "the region belongs to a region set");
543 545 } else {
544 546 assert( _pending_removal && containing_set() == NULL,
545 547 "can only set pending removal to false if it's true and "
546 548 "the region does not belong to a region set");
547 549 }
548 550
549 551 _pending_removal = pending_removal;
550 552 }
551 553
552 554 HeapRegion* get_next_young_region() { return _next_young_region; }
553 555 void set_next_young_region(HeapRegion* hr) {
554 556 _next_young_region = hr;
555 557 }
556 558
557 559 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; }
558 560 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; }
559 561 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; }
560 562 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; }
561 563
562 564 HeapWord* orig_end() { return _orig_end; }
563 565
564 566 // Allows logical separation between objects allocated before and after.
565 567 void save_marks();
566 568
567 569 // Reset HR stuff to default values.
568 570 void hr_clear(bool par, bool clear_space);
569 571 void par_clear();
570 572
571 573 void initialize(MemRegion mr, bool clear_space, bool mangle_space);
572 574
573 575 // Get the start of the unmarked area in this region.
574 576 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }
575 577 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }
576 578
577 579 // Apply "cl->do_oop" to (the addresses of) all reference fields in objects
578 580 // allocated in the current region before the last call to "save_mark".
579 581 void oop_before_save_marks_iterate(OopClosure* cl);
580 582
581 583 // Note the start or end of marking. This tells the heap region
582 584 // that the collector is about to start or has finished (concurrently)
583 585 // marking the heap.
584 586
585 587 // Note the start of a marking phase. Record the
586 588 // start of the unmarked area of the region here.
587 589 void note_start_of_marking(bool during_initial_mark) {
588 590 init_top_at_conc_mark_count();
589 591 _next_marked_bytes = 0;
590 592 if (during_initial_mark && is_young() && !is_survivor())
591 593 _next_top_at_mark_start = bottom();
592 594 else
593 595 _next_top_at_mark_start = top();
594 596 }
595 597
596 598 // Note the end of a marking phase. Install the start of
597 599 // the unmarked area that was captured at start of marking.
598 600 void note_end_of_marking() {
599 601 _prev_top_at_mark_start = _next_top_at_mark_start;
600 602 _prev_marked_bytes = _next_marked_bytes;
601 603 _next_marked_bytes = 0;
602 604
603 605 guarantee(_prev_marked_bytes <=
604 606 (size_t) (prev_top_at_mark_start() - bottom()) * HeapWordSize,
605 607 "invariant");
606 608 }
607 609
608 610 // After an evacuation, we need to update _next_top_at_mark_start
609 611 // to be the current top. Note this is only valid if we have only
610 612 // ever evacuated into this region. If we evacuate, allocate, and
611 613 // then evacuate we are in deep doodoo.
612 614 void note_end_of_copying() {
613 615 assert(top() >= _next_top_at_mark_start, "Increase only");
614 616 _next_top_at_mark_start = top();
615 617 }
616 618
617 619 // Returns "false" iff no object in the region was allocated when the
618 620 // last mark phase ended.
619 621 bool is_marked() { return _prev_top_at_mark_start != bottom(); }
620 622
621 623 // If "is_marked()" is true, then this is the index of the region in
622 624 // an array constructed at the end of marking of the regions in a
623 625 // "desirability" order.
624 626 int sort_index() {
625 627 return _sort_index;
626 628 }
627 629 void set_sort_index(int i) {
628 630 _sort_index = i;
629 631 }
630 632
631 633 void init_top_at_conc_mark_count() {
632 634 _top_at_conc_mark_count = bottom();
633 635 }
634 636
635 637 void set_top_at_conc_mark_count(HeapWord *cur) {
636 638 assert(bottom() <= cur && cur <= end(), "Sanity.");
637 639 _top_at_conc_mark_count = cur;
638 640 }
639 641
640 642 HeapWord* top_at_conc_mark_count() {
641 643 return _top_at_conc_mark_count;
642 644 }
643 645
644 646 void reset_during_compaction() {
645 647 guarantee( isHumongous() && startsHumongous(),
646 648 "should only be called for humongous regions");
647 649
648 650 zero_marked_bytes();
649 651 init_top_at_mark_start();
650 652 }
651 653
652 654 // <PREDICTION>
653 655 void calc_gc_efficiency(void);
654 656 double gc_efficiency() { return _gc_efficiency;}
655 657 // </PREDICTION>
656 658
657 659 bool is_young() const { return _young_type != NotYoung; }
658 660 bool is_survivor() const { return _young_type == Survivor; }
659 661
660 662 int young_index_in_cset() const { return _young_index_in_cset; }
661 663 void set_young_index_in_cset(int index) {
662 664 assert( (index == -1) || is_young(), "pre-condition" );
663 665 _young_index_in_cset = index;
664 666 }
665 667
666 668 int age_in_surv_rate_group() {
667 669 assert( _surv_rate_group != NULL, "pre-condition" );
668 670 assert( _age_index > -1, "pre-condition" );
669 671 return _surv_rate_group->age_in_group(_age_index);
670 672 }
671 673
672 674 void record_surv_words_in_group(size_t words_survived) {
673 675 assert( _surv_rate_group != NULL, "pre-condition" );
674 676 assert( _age_index > -1, "pre-condition" );
675 677 int age_in_group = age_in_surv_rate_group();
676 678 _surv_rate_group->record_surviving_words(age_in_group, words_survived);
677 679 }
678 680
679 681 int age_in_surv_rate_group_cond() {
680 682 if (_surv_rate_group != NULL)
681 683 return age_in_surv_rate_group();
682 684 else
683 685 return -1;
684 686 }
685 687
686 688 SurvRateGroup* surv_rate_group() {
687 689 return _surv_rate_group;
688 690 }
689 691
690 692 void install_surv_rate_group(SurvRateGroup* surv_rate_group) {
691 693 assert( surv_rate_group != NULL, "pre-condition" );
692 694 assert( _surv_rate_group == NULL, "pre-condition" );
693 695 assert( is_young(), "pre-condition" );
694 696
695 697 _surv_rate_group = surv_rate_group;
696 698 _age_index = surv_rate_group->next_age_index();
697 699 }
698 700
699 701 void uninstall_surv_rate_group() {
700 702 if (_surv_rate_group != NULL) {
701 703 assert( _age_index > -1, "pre-condition" );
702 704 assert( is_young(), "pre-condition" );
703 705
704 706 _surv_rate_group = NULL;
705 707 _age_index = -1;
706 708 } else {
707 709 assert( _age_index == -1, "pre-condition" );
708 710 }
709 711 }
710 712
711 713 void set_young() { set_young_type(Young); }
712 714
713 715 void set_survivor() { set_young_type(Survivor); }
714 716
715 717 void set_not_young() { set_young_type(NotYoung); }
716 718
717 719 // Determine if an object has been allocated since the last
718 720 // mark performed by the collector. This returns true iff the object
719 721 // is within the unmarked area of the region.
720 722 bool obj_allocated_since_prev_marking(oop obj) const {
721 723 return (HeapWord *) obj >= prev_top_at_mark_start();
722 724 }
723 725 bool obj_allocated_since_next_marking(oop obj) const {
724 726 return (HeapWord *) obj >= next_top_at_mark_start();
725 727 }
726 728
727 729 // For parallel heapRegion traversal.
728 730 bool claimHeapRegion(int claimValue);
729 731 jint claim_value() { return _claimed; }
730 732 // Use this carefully: only when you're sure no one is claiming...
731 733 void set_claim_value(int claimValue) { _claimed = claimValue; }
732 734
733 735 // Returns the "evacuation_failed" property of the region.
734 736 bool evacuation_failed() { return _evacuation_failed; }
735 737
736 738 // Sets the "evacuation_failed" property of the region.
737 739 void set_evacuation_failed(bool b) {
738 740 _evacuation_failed = b;
739 741
740 742 if (b) {
741 743 init_top_at_conc_mark_count();
742 744 _next_marked_bytes = 0;
743 745 }
744 746 }
745 747
746 748 // Requires that "mr" be entirely within the region.
747 749 // Apply "cl->do_object" to all objects that intersect with "mr".
748 750 // If the iteration encounters an unparseable portion of the region,
749 751 // or if "cl->abort()" is true after a closure application,
750 752 // terminate the iteration and return the address of the start of the
751 753 // subregion that isn't done. (The two can be distinguished by querying
752 754 // "cl->abort()".) Return of "NULL" indicates that the iteration
753 755 // completed.
754 756 HeapWord*
755 757 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl);
756 758
757 759 // filter_young: if true and the region is a young region then we
758 760 // skip the iteration.
759 761 // card_ptr: if not NULL, and we decide that the card is not young
760 762 // and we iterate over it, we'll clean the card before we start the
761 763 // iteration.
762 764 HeapWord*
763 765 oops_on_card_seq_iterate_careful(MemRegion mr,
764 766 FilterOutOfRegionClosure* cl,
765 767 bool filter_young,
766 768 jbyte* card_ptr);
767 769
768 770 // A version of block start that is guaranteed to find *some* block
769 771 // boundary at or before "p", but does not object iteration, and may
770 772 // therefore be used safely when the heap is unparseable.
771 773 HeapWord* block_start_careful(const void* p) const {
772 774 return _offsets.block_start_careful(p);
773 775 }
774 776
775 777 // Requires that "addr" is within the region. Returns the start of the
776 778 // first ("careful") block that starts at or after "addr", or else the
777 779 // "end" of the region if there is no such block.
778 780 HeapWord* next_block_start_careful(HeapWord* addr);
779 781
780 782 size_t recorded_rs_length() const { return _recorded_rs_length; }
781 783 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
782 784 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; }
783 785
784 786 void set_recorded_rs_length(size_t rs_length) {
785 787 _recorded_rs_length = rs_length;
786 788 }
787 789
788 790 void set_predicted_elapsed_time_ms(double ms) {
789 791 _predicted_elapsed_time_ms = ms;
790 792 }
791 793
792 794 void set_predicted_bytes_to_copy(size_t bytes) {
793 795 _predicted_bytes_to_copy = bytes;
794 796 }
795 797
796 798 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
797 799 virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
798 800 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
799 801
800 802 CompactibleSpace* next_compaction_space() const;
801 803
802 804 virtual void reset_after_compaction();
803 805
804 806 void print() const;
805 807 void print_on(outputStream* st) const;
806 808
807 809 // vo == UsePrevMarking -> use "prev" marking information,
808 810 // vo == UseNextMarking -> use "next" marking information
809 811 // vo == UseMarkWord -> use the mark word in the object header
810 812 //
811 813 // NOTE: Only the "prev" marking information is guaranteed to be
812 814 // consistent most of the time, so most calls to this should use
813 815 // vo == UsePrevMarking.
814 816 // Currently, there is only one case where this is called with
815 817 // vo == UseNextMarking, which is to verify the "next" marking
816 818 // information at the end of remark.
817 819 // Currently there is only one place where this is called with
818 820 // vo == UseMarkWord, which is to verify the marking during a
819 821 // full GC.
820 822 void verify(bool allow_dirty, VerifyOption vo, bool *failures) const;
821 823
822 824 // Override; it uses the "prev" marking information
823 825 virtual void verify(bool allow_dirty) const;
824 826 };
825 827
826 828 // HeapRegionClosure is used for iterating over regions.
827 829 // Terminates the iteration when the "doHeapRegion" method returns "true".
828 830 class HeapRegionClosure : public StackObj {
829 831 friend class HeapRegionSeq;
830 832 friend class G1CollectedHeap;
831 833
832 834 bool _complete;
833 835 void incomplete() { _complete = false; }
834 836
835 837 public:
836 838 HeapRegionClosure(): _complete(true) {}
837 839
838 840 // Typically called on each region until it returns true.
839 841 virtual bool doHeapRegion(HeapRegion* r) = 0;
840 842
841 843 // True after iteration if the closure was applied to all heap regions
842 844 // and returned "false" in all cases.
843 845 bool complete() { return _complete; }
844 846 };
845 847
846 848 #endif // SERIALGC
847 849
848 850 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP
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