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rev 2591 : [mq]: g1-reference-processing
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--- old/src/share/vm/gc_implementation/g1/heapRegion.cpp
+++ new/src/share/vm/gc_implementation/g1/heapRegion.cpp
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 #include "precompiled.hpp"
26 26 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
27 27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
28 28 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
29 29 #include "gc_implementation/g1/heapRegion.inline.hpp"
30 30 #include "gc_implementation/g1/heapRegionRemSet.hpp"
31 31 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
32 32 #include "memory/genOopClosures.inline.hpp"
33 33 #include "memory/iterator.hpp"
34 34 #include "oops/oop.inline.hpp"
35 35
36 36 int HeapRegion::LogOfHRGrainBytes = 0;
37 37 int HeapRegion::LogOfHRGrainWords = 0;
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38 38 int HeapRegion::GrainBytes = 0;
39 39 int HeapRegion::GrainWords = 0;
40 40 int HeapRegion::CardsPerRegion = 0;
41 41
42 42 HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1,
43 43 HeapRegion* hr, OopClosure* cl,
44 44 CardTableModRefBS::PrecisionStyle precision,
45 45 FilterKind fk) :
46 46 ContiguousSpaceDCTOC(hr, cl, precision, NULL),
47 47 _hr(hr), _fk(fk), _g1(g1)
48 -{}
48 +{ }
49 49
50 50 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r,
51 51 OopClosure* oc) :
52 52 _r_bottom(r->bottom()), _r_end(r->end()),
53 53 _oc(oc), _out_of_region(0)
54 54 {}
55 55
56 56 class VerifyLiveClosure: public OopClosure {
57 57 private:
58 58 G1CollectedHeap* _g1h;
59 59 CardTableModRefBS* _bs;
60 60 oop _containing_obj;
61 61 bool _failures;
62 62 int _n_failures;
63 63 VerifyOption _vo;
64 64 public:
65 65 // _vo == UsePrevMarking -> use "prev" marking information,
66 66 // _vo == UseNextMarking -> use "next" marking information,
67 67 // _vo == UseMarkWord -> use mark word from object header.
68 68 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) :
69 69 _g1h(g1h), _bs(NULL), _containing_obj(NULL),
70 70 _failures(false), _n_failures(0), _vo(vo)
71 71 {
72 72 BarrierSet* bs = _g1h->barrier_set();
73 73 if (bs->is_a(BarrierSet::CardTableModRef))
74 74 _bs = (CardTableModRefBS*)bs;
75 75 }
76 76
77 77 void set_containing_obj(oop obj) {
78 78 _containing_obj = obj;
79 79 }
80 80
81 81 bool failures() { return _failures; }
82 82 int n_failures() { return _n_failures; }
83 83
84 84 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
85 85 virtual void do_oop( oop* p) { do_oop_work(p); }
86 86
87 87 void print_object(outputStream* out, oop obj) {
88 88 #ifdef PRODUCT
89 89 klassOop k = obj->klass();
90 90 const char* class_name = instanceKlass::cast(k)->external_name();
91 91 out->print_cr("class name %s", class_name);
92 92 #else // PRODUCT
93 93 obj->print_on(out);
94 94 #endif // PRODUCT
95 95 }
96 96
97 97 template <class T> void do_oop_work(T* p) {
98 98 assert(_containing_obj != NULL, "Precondition");
99 99 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
100 100 "Precondition");
101 101 T heap_oop = oopDesc::load_heap_oop(p);
102 102 if (!oopDesc::is_null(heap_oop)) {
103 103 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
104 104 bool failed = false;
105 105 if (!_g1h->is_in_closed_subset(obj) ||
106 106 _g1h->is_obj_dead_cond(obj, _vo)) {
107 107 if (!_failures) {
108 108 gclog_or_tty->print_cr("");
109 109 gclog_or_tty->print_cr("----------");
110 110 }
111 111 if (!_g1h->is_in_closed_subset(obj)) {
112 112 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
113 113 gclog_or_tty->print_cr("Field "PTR_FORMAT
114 114 " of live obj "PTR_FORMAT" in region "
115 115 "["PTR_FORMAT", "PTR_FORMAT")",
116 116 p, (void*) _containing_obj,
117 117 from->bottom(), from->end());
118 118 print_object(gclog_or_tty, _containing_obj);
119 119 gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap",
120 120 (void*) obj);
121 121 } else {
122 122 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
123 123 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
124 124 gclog_or_tty->print_cr("Field "PTR_FORMAT
125 125 " of live obj "PTR_FORMAT" in region "
126 126 "["PTR_FORMAT", "PTR_FORMAT")",
127 127 p, (void*) _containing_obj,
128 128 from->bottom(), from->end());
129 129 print_object(gclog_or_tty, _containing_obj);
130 130 gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region "
131 131 "["PTR_FORMAT", "PTR_FORMAT")",
132 132 (void*) obj, to->bottom(), to->end());
133 133 print_object(gclog_or_tty, obj);
134 134 }
135 135 gclog_or_tty->print_cr("----------");
136 136 _failures = true;
137 137 failed = true;
138 138 _n_failures++;
139 139 }
140 140
141 141 if (!_g1h->full_collection()) {
142 142 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
143 143 HeapRegion* to = _g1h->heap_region_containing(obj);
144 144 if (from != NULL && to != NULL &&
145 145 from != to &&
146 146 !to->isHumongous()) {
147 147 jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
148 148 jbyte cv_field = *_bs->byte_for_const(p);
149 149 const jbyte dirty = CardTableModRefBS::dirty_card_val();
150 150
151 151 bool is_bad = !(from->is_young()
152 152 || to->rem_set()->contains_reference(p)
153 153 || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed
154 154 (_containing_obj->is_objArray() ?
155 155 cv_field == dirty
156 156 : cv_obj == dirty || cv_field == dirty));
157 157 if (is_bad) {
158 158 if (!_failures) {
159 159 gclog_or_tty->print_cr("");
160 160 gclog_or_tty->print_cr("----------");
161 161 }
162 162 gclog_or_tty->print_cr("Missing rem set entry:");
163 163 gclog_or_tty->print_cr("Field "PTR_FORMAT" "
164 164 "of obj "PTR_FORMAT", "
165 165 "in region "HR_FORMAT,
166 166 p, (void*) _containing_obj,
167 167 HR_FORMAT_PARAMS(from));
168 168 _containing_obj->print_on(gclog_or_tty);
169 169 gclog_or_tty->print_cr("points to obj "PTR_FORMAT" "
170 170 "in region "HR_FORMAT,
171 171 (void*) obj,
172 172 HR_FORMAT_PARAMS(to));
173 173 obj->print_on(gclog_or_tty);
174 174 gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.",
175 175 cv_obj, cv_field);
176 176 gclog_or_tty->print_cr("----------");
177 177 _failures = true;
178 178 if (!failed) _n_failures++;
179 179 }
180 180 }
181 181 }
182 182 }
183 183 }
184 184 };
185 185
186 186 template<class ClosureType>
187 187 HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h,
188 188 HeapRegion* hr,
189 189 HeapWord* cur, HeapWord* top) {
190 190 oop cur_oop = oop(cur);
191 191 int oop_size = cur_oop->size();
192 192 HeapWord* next_obj = cur + oop_size;
193 193 while (next_obj < top) {
194 194 // Keep filtering the remembered set.
195 195 if (!g1h->is_obj_dead(cur_oop, hr)) {
196 196 // Bottom lies entirely below top, so we can call the
197 197 // non-memRegion version of oop_iterate below.
198 198 cur_oop->oop_iterate(cl);
199 199 }
200 200 cur = next_obj;
201 201 cur_oop = oop(cur);
202 202 oop_size = cur_oop->size();
203 203 next_obj = cur + oop_size;
204 204 }
205 205 return cur;
206 206 }
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207 207
208 208 void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
209 209 HeapWord* bottom,
210 210 HeapWord* top,
211 211 OopClosure* cl) {
212 212 G1CollectedHeap* g1h = _g1;
213 213
214 214 int oop_size;
215 215
216 216 OopClosure* cl2 = cl;
217 - FilterIntoCSClosure intoCSFilt(this, g1h, cl);
217 +
218 + // If we are scanning the remembered sets looking for refs
219 + // into the collection set during an evacuation pause then
220 + // we will want to 'discover' reference objects that point
221 + // to referents in the collection set.
222 + //
223 + // Unfortunately it is an instance of FilterIntoCSClosure
224 + // that is iterated over the reference fields of oops in
225 + // mr (and not the G1ParPushHeapRSClosure - which is the
226 + // cl parameter).
227 + // If we set the _ref_processor field in the FilterIntoCSClosure
228 + // instance, all the reference objects that are walked
229 + // (regardless of whether their referent object's are in
230 + // the cset) will be 'discovered'.
231 + //
232 + // The G1STWIsAlive closure considers a referent object that
233 + // is outside the cset as alive. The G1CopyingKeepAliveClosure
234 + // skips referents that are not in the cset.
235 + //
236 + // Therefore reference objects in mr with a referent that is
237 + // outside the cset should be OK.
238 +
239 + ReferenceProcessor* rp = _cl->_ref_processor;
240 + if (rp != NULL) {
241 + assert(rp == _g1->ref_processor_stw(), "should be stw");
242 + assert(_fk == IntoCSFilterKind, "should be looking for refs into CS");
243 + }
244 +
245 + FilterIntoCSClosure intoCSFilt(this, g1h, cl, rp);
218 246 FilterOutOfRegionClosure outOfRegionFilt(_hr, cl);
247 +
219 248 switch (_fk) {
220 249 case IntoCSFilterKind: cl2 = &intoCSFilt; break;
221 250 case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break;
222 251 }
223 252
224 253 // Start filtering what we add to the remembered set. If the object is
225 254 // not considered dead, either because it is marked (in the mark bitmap)
226 255 // or it was allocated after marking finished, then we add it. Otherwise
227 256 // we can safely ignore the object.
228 257 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
229 258 oop_size = oop(bottom)->oop_iterate(cl2, mr);
230 259 } else {
231 260 oop_size = oop(bottom)->size();
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232 261 }
233 262
234 263 bottom += oop_size;
235 264
236 265 if (bottom < top) {
237 266 // We replicate the loop below for several kinds of possible filters.
238 267 switch (_fk) {
239 268 case NoFilterKind:
240 269 bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top);
241 270 break;
271 +
242 272 case IntoCSFilterKind: {
243 - FilterIntoCSClosure filt(this, g1h, cl);
273 + FilterIntoCSClosure filt(this, g1h, cl, rp);
244 274 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
245 275 break;
246 276 }
277 +
247 278 case OutOfRegionFilterKind: {
248 279 FilterOutOfRegionClosure filt(_hr, cl);
249 280 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
250 281 break;
251 282 }
283 +
252 284 default:
253 285 ShouldNotReachHere();
254 286 }
255 287
256 288 // Last object. Need to do dead-obj filtering here too.
257 289 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
258 290 oop(bottom)->oop_iterate(cl2, mr);
259 291 }
260 292 }
261 293 }
262 294
263 295 // Minimum region size; we won't go lower than that.
264 296 // We might want to decrease this in the future, to deal with small
265 297 // heaps a bit more efficiently.
266 298 #define MIN_REGION_SIZE ( 1024 * 1024 )
267 299
268 300 // Maximum region size; we don't go higher than that. There's a good
269 301 // reason for having an upper bound. We don't want regions to get too
270 302 // large, otherwise cleanup's effectiveness would decrease as there
271 303 // will be fewer opportunities to find totally empty regions after
272 304 // marking.
273 305 #define MAX_REGION_SIZE ( 32 * 1024 * 1024 )
274 306
275 307 // The automatic region size calculation will try to have around this
276 308 // many regions in the heap (based on the min heap size).
277 309 #define TARGET_REGION_NUMBER 2048
278 310
279 311 void HeapRegion::setup_heap_region_size(uintx min_heap_size) {
280 312 // region_size in bytes
281 313 uintx region_size = G1HeapRegionSize;
282 314 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
283 315 // We base the automatic calculation on the min heap size. This
284 316 // can be problematic if the spread between min and max is quite
285 317 // wide, imagine -Xms128m -Xmx32g. But, if we decided it based on
286 318 // the max size, the region size might be way too large for the
287 319 // min size. Either way, some users might have to set the region
288 320 // size manually for some -Xms / -Xmx combos.
289 321
290 322 region_size = MAX2(min_heap_size / TARGET_REGION_NUMBER,
291 323 (uintx) MIN_REGION_SIZE);
292 324 }
293 325
294 326 int region_size_log = log2_long((jlong) region_size);
295 327 // Recalculate the region size to make sure it's a power of
296 328 // 2. This means that region_size is the largest power of 2 that's
297 329 // <= what we've calculated so far.
298 330 region_size = ((uintx)1 << region_size_log);
299 331
300 332 // Now make sure that we don't go over or under our limits.
301 333 if (region_size < MIN_REGION_SIZE) {
302 334 region_size = MIN_REGION_SIZE;
303 335 } else if (region_size > MAX_REGION_SIZE) {
304 336 region_size = MAX_REGION_SIZE;
305 337 }
306 338
307 339 // And recalculate the log.
308 340 region_size_log = log2_long((jlong) region_size);
309 341
310 342 // Now, set up the globals.
311 343 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
312 344 LogOfHRGrainBytes = region_size_log;
313 345
314 346 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
315 347 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
316 348
317 349 guarantee(GrainBytes == 0, "we should only set it once");
318 350 // The cast to int is safe, given that we've bounded region_size by
319 351 // MIN_REGION_SIZE and MAX_REGION_SIZE.
320 352 GrainBytes = (int) region_size;
321 353
322 354 guarantee(GrainWords == 0, "we should only set it once");
323 355 GrainWords = GrainBytes >> LogHeapWordSize;
324 356 guarantee(1 << LogOfHRGrainWords == GrainWords, "sanity");
325 357
326 358 guarantee(CardsPerRegion == 0, "we should only set it once");
327 359 CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift;
328 360 }
329 361
330 362 void HeapRegion::reset_after_compaction() {
331 363 G1OffsetTableContigSpace::reset_after_compaction();
332 364 // After a compaction the mark bitmap is invalid, so we must
333 365 // treat all objects as being inside the unmarked area.
334 366 zero_marked_bytes();
335 367 init_top_at_mark_start();
336 368 }
337 369
338 370 DirtyCardToOopClosure*
339 371 HeapRegion::new_dcto_closure(OopClosure* cl,
340 372 CardTableModRefBS::PrecisionStyle precision,
341 373 HeapRegionDCTOC::FilterKind fk) {
342 374 return new HeapRegionDCTOC(G1CollectedHeap::heap(),
343 375 this, cl, precision, fk);
344 376 }
345 377
346 378 void HeapRegion::hr_clear(bool par, bool clear_space) {
347 379 assert(_humongous_type == NotHumongous,
348 380 "we should have already filtered out humongous regions");
349 381 assert(_humongous_start_region == NULL,
350 382 "we should have already filtered out humongous regions");
351 383 assert(_end == _orig_end,
352 384 "we should have already filtered out humongous regions");
353 385
354 386 _in_collection_set = false;
355 387
356 388 set_young_index_in_cset(-1);
357 389 uninstall_surv_rate_group();
358 390 set_young_type(NotYoung);
359 391 reset_pre_dummy_top();
360 392
361 393 if (!par) {
362 394 // If this is parallel, this will be done later.
363 395 HeapRegionRemSet* hrrs = rem_set();
364 396 if (hrrs != NULL) hrrs->clear();
365 397 _claimed = InitialClaimValue;
366 398 }
367 399 zero_marked_bytes();
368 400 set_sort_index(-1);
369 401
370 402 _offsets.resize(HeapRegion::GrainWords);
371 403 init_top_at_mark_start();
372 404 if (clear_space) clear(SpaceDecorator::Mangle);
373 405 }
374 406
375 407 void HeapRegion::par_clear() {
376 408 assert(used() == 0, "the region should have been already cleared");
377 409 assert(capacity() == (size_t) HeapRegion::GrainBytes,
378 410 "should be back to normal");
379 411 HeapRegionRemSet* hrrs = rem_set();
380 412 hrrs->clear();
381 413 CardTableModRefBS* ct_bs =
382 414 (CardTableModRefBS*)G1CollectedHeap::heap()->barrier_set();
383 415 ct_bs->clear(MemRegion(bottom(), end()));
384 416 }
385 417
386 418 // <PREDICTION>
387 419 void HeapRegion::calc_gc_efficiency() {
388 420 G1CollectedHeap* g1h = G1CollectedHeap::heap();
389 421 _gc_efficiency = (double) garbage_bytes() /
390 422 g1h->predict_region_elapsed_time_ms(this, false);
391 423 }
392 424 // </PREDICTION>
393 425
394 426 void HeapRegion::set_startsHumongous(HeapWord* new_top, HeapWord* new_end) {
395 427 assert(!isHumongous(), "sanity / pre-condition");
396 428 assert(end() == _orig_end,
397 429 "Should be normal before the humongous object allocation");
398 430 assert(top() == bottom(), "should be empty");
399 431 assert(bottom() <= new_top && new_top <= new_end, "pre-condition");
400 432
401 433 _humongous_type = StartsHumongous;
402 434 _humongous_start_region = this;
403 435
404 436 set_end(new_end);
405 437 _offsets.set_for_starts_humongous(new_top);
406 438 }
407 439
408 440 void HeapRegion::set_continuesHumongous(HeapRegion* first_hr) {
409 441 assert(!isHumongous(), "sanity / pre-condition");
410 442 assert(end() == _orig_end,
411 443 "Should be normal before the humongous object allocation");
412 444 assert(top() == bottom(), "should be empty");
413 445 assert(first_hr->startsHumongous(), "pre-condition");
414 446
415 447 _humongous_type = ContinuesHumongous;
416 448 _humongous_start_region = first_hr;
417 449 }
418 450
419 451 void HeapRegion::set_notHumongous() {
420 452 assert(isHumongous(), "pre-condition");
421 453
422 454 if (startsHumongous()) {
423 455 assert(top() <= end(), "pre-condition");
424 456 set_end(_orig_end);
425 457 if (top() > end()) {
426 458 // at least one "continues humongous" region after it
427 459 set_top(end());
428 460 }
429 461 } else {
430 462 // continues humongous
431 463 assert(end() == _orig_end, "sanity");
432 464 }
433 465
434 466 assert(capacity() == (size_t) HeapRegion::GrainBytes, "pre-condition");
435 467 _humongous_type = NotHumongous;
436 468 _humongous_start_region = NULL;
437 469 }
438 470
439 471 bool HeapRegion::claimHeapRegion(jint claimValue) {
440 472 jint current = _claimed;
441 473 if (current != claimValue) {
442 474 jint res = Atomic::cmpxchg(claimValue, &_claimed, current);
443 475 if (res == current) {
444 476 return true;
445 477 }
446 478 }
447 479 return false;
448 480 }
449 481
450 482 HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) {
451 483 HeapWord* low = addr;
452 484 HeapWord* high = end();
453 485 while (low < high) {
454 486 size_t diff = pointer_delta(high, low);
455 487 // Must add one below to bias toward the high amount. Otherwise, if
456 488 // "high" were at the desired value, and "low" were one less, we
457 489 // would not converge on "high". This is not symmetric, because
458 490 // we set "high" to a block start, which might be the right one,
459 491 // which we don't do for "low".
460 492 HeapWord* middle = low + (diff+1)/2;
461 493 if (middle == high) return high;
462 494 HeapWord* mid_bs = block_start_careful(middle);
463 495 if (mid_bs < addr) {
464 496 low = middle;
465 497 } else {
466 498 high = mid_bs;
467 499 }
468 500 }
469 501 assert(low == high && low >= addr, "Didn't work.");
470 502 return low;
471 503 }
472 504
473 505 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
474 506 G1OffsetTableContigSpace::initialize(mr, false, mangle_space);
475 507 hr_clear(false/*par*/, clear_space);
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476 508 }
477 509 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
478 510 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
479 511 #endif // _MSC_VER
480 512
481 513
482 514 HeapRegion::
483 515 HeapRegion(size_t hrs_index, G1BlockOffsetSharedArray* sharedOffsetArray,
484 516 MemRegion mr, bool is_zeroed)
485 517 : G1OffsetTableContigSpace(sharedOffsetArray, mr, is_zeroed),
486 - _next_fk(HeapRegionDCTOC::NoFilterKind), _hrs_index(hrs_index),
518 + _hrs_index(hrs_index),
487 519 _humongous_type(NotHumongous), _humongous_start_region(NULL),
488 520 _in_collection_set(false),
489 521 _next_in_special_set(NULL), _orig_end(NULL),
490 522 _claimed(InitialClaimValue), _evacuation_failed(false),
491 523 _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1),
492 524 _young_type(NotYoung), _next_young_region(NULL),
493 525 _next_dirty_cards_region(NULL), _next(NULL), _pending_removal(false),
494 526 #ifdef ASSERT
495 527 _containing_set(NULL),
496 528 #endif // ASSERT
497 529 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
498 530 _rem_set(NULL), _recorded_rs_length(0), _predicted_elapsed_time_ms(0),
499 531 _predicted_bytes_to_copy(0)
500 532 {
501 533 _orig_end = mr.end();
502 534 // Note that initialize() will set the start of the unmarked area of the
503 535 // region.
504 536 this->initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
505 537 set_top(bottom());
506 538 set_saved_mark();
507 539
508 540 _rem_set = new HeapRegionRemSet(sharedOffsetArray, this);
509 541
510 542 assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant.");
511 543 // In case the region is allocated during a pause, note the top.
512 544 // We haven't done any counting on a brand new region.
513 545 _top_at_conc_mark_count = bottom();
514 546 }
515 547
516 548 class NextCompactionHeapRegionClosure: public HeapRegionClosure {
517 549 const HeapRegion* _target;
518 550 bool _target_seen;
519 551 HeapRegion* _last;
520 552 CompactibleSpace* _res;
521 553 public:
522 554 NextCompactionHeapRegionClosure(const HeapRegion* target) :
523 555 _target(target), _target_seen(false), _res(NULL) {}
524 556 bool doHeapRegion(HeapRegion* cur) {
525 557 if (_target_seen) {
526 558 if (!cur->isHumongous()) {
527 559 _res = cur;
528 560 return true;
529 561 }
530 562 } else if (cur == _target) {
531 563 _target_seen = true;
532 564 }
533 565 return false;
534 566 }
535 567 CompactibleSpace* result() { return _res; }
536 568 };
537 569
538 570 CompactibleSpace* HeapRegion::next_compaction_space() const {
539 571 G1CollectedHeap* g1h = G1CollectedHeap::heap();
540 572 // cast away const-ness
541 573 HeapRegion* r = (HeapRegion*) this;
542 574 NextCompactionHeapRegionClosure blk(r);
543 575 g1h->heap_region_iterate_from(r, &blk);
544 576 return blk.result();
545 577 }
546 578
547 579 void HeapRegion::save_marks() {
548 580 set_saved_mark();
549 581 }
550 582
551 583 void HeapRegion::oops_in_mr_iterate(MemRegion mr, OopClosure* cl) {
552 584 HeapWord* p = mr.start();
553 585 HeapWord* e = mr.end();
554 586 oop obj;
555 587 while (p < e) {
556 588 obj = oop(p);
557 589 p += obj->oop_iterate(cl);
558 590 }
559 591 assert(p == e, "bad memregion: doesn't end on obj boundary");
560 592 }
561 593
562 594 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
563 595 void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \
564 596 ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl); \
565 597 }
566 598 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN)
567 599
568 600
569 601 void HeapRegion::oop_before_save_marks_iterate(OopClosure* cl) {
570 602 oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
571 603 }
572 604
573 605 HeapWord*
574 606 HeapRegion::object_iterate_mem_careful(MemRegion mr,
575 607 ObjectClosure* cl) {
576 608 G1CollectedHeap* g1h = G1CollectedHeap::heap();
577 609 // We used to use "block_start_careful" here. But we're actually happy
578 610 // to update the BOT while we do this...
579 611 HeapWord* cur = block_start(mr.start());
580 612 mr = mr.intersection(used_region());
581 613 if (mr.is_empty()) return NULL;
582 614 // Otherwise, find the obj that extends onto mr.start().
583 615
584 616 assert(cur <= mr.start()
585 617 && (oop(cur)->klass_or_null() == NULL ||
586 618 cur + oop(cur)->size() > mr.start()),
587 619 "postcondition of block_start");
588 620 oop obj;
589 621 while (cur < mr.end()) {
590 622 obj = oop(cur);
591 623 if (obj->klass_or_null() == NULL) {
592 624 // Ran into an unparseable point.
593 625 return cur;
594 626 } else if (!g1h->is_obj_dead(obj)) {
595 627 cl->do_object(obj);
596 628 }
597 629 if (cl->abort()) return cur;
598 630 // The check above must occur before the operation below, since an
599 631 // abort might invalidate the "size" operation.
600 632 cur += obj->size();
601 633 }
602 634 return NULL;
603 635 }
604 636
605 637 HeapWord*
606 638 HeapRegion::
607 639 oops_on_card_seq_iterate_careful(MemRegion mr,
608 640 FilterOutOfRegionClosure* cl,
609 641 bool filter_young,
610 642 jbyte* card_ptr) {
611 643 // Currently, we should only have to clean the card if filter_young
612 644 // is true and vice versa.
613 645 if (filter_young) {
614 646 assert(card_ptr != NULL, "pre-condition");
615 647 } else {
616 648 assert(card_ptr == NULL, "pre-condition");
617 649 }
618 650 G1CollectedHeap* g1h = G1CollectedHeap::heap();
619 651
620 652 // If we're within a stop-world GC, then we might look at a card in a
621 653 // GC alloc region that extends onto a GC LAB, which may not be
622 654 // parseable. Stop such at the "saved_mark" of the region.
623 655 if (G1CollectedHeap::heap()->is_gc_active()) {
624 656 mr = mr.intersection(used_region_at_save_marks());
625 657 } else {
626 658 mr = mr.intersection(used_region());
627 659 }
628 660 if (mr.is_empty()) return NULL;
629 661 // Otherwise, find the obj that extends onto mr.start().
630 662
631 663 // The intersection of the incoming mr (for the card) and the
632 664 // allocated part of the region is non-empty. This implies that
633 665 // we have actually allocated into this region. The code in
634 666 // G1CollectedHeap.cpp that allocates a new region sets the
635 667 // is_young tag on the region before allocating. Thus we
636 668 // safely know if this region is young.
637 669 if (is_young() && filter_young) {
638 670 return NULL;
639 671 }
640 672
641 673 assert(!is_young(), "check value of filter_young");
642 674
643 675 // We can only clean the card here, after we make the decision that
644 676 // the card is not young. And we only clean the card if we have been
645 677 // asked to (i.e., card_ptr != NULL).
646 678 if (card_ptr != NULL) {
647 679 *card_ptr = CardTableModRefBS::clean_card_val();
648 680 // We must complete this write before we do any of the reads below.
649 681 OrderAccess::storeload();
650 682 }
651 683
652 684 // We used to use "block_start_careful" here. But we're actually happy
653 685 // to update the BOT while we do this...
654 686 HeapWord* cur = block_start(mr.start());
655 687 assert(cur <= mr.start(), "Postcondition");
656 688
657 689 while (cur <= mr.start()) {
658 690 if (oop(cur)->klass_or_null() == NULL) {
659 691 // Ran into an unparseable point.
660 692 return cur;
661 693 }
662 694 // Otherwise...
663 695 int sz = oop(cur)->size();
664 696 if (cur + sz > mr.start()) break;
665 697 // Otherwise, go on.
666 698 cur = cur + sz;
667 699 }
668 700 oop obj;
669 701 obj = oop(cur);
670 702 // If we finish this loop...
671 703 assert(cur <= mr.start()
672 704 && obj->klass_or_null() != NULL
673 705 && cur + obj->size() > mr.start(),
674 706 "Loop postcondition");
675 707 if (!g1h->is_obj_dead(obj)) {
676 708 obj->oop_iterate(cl, mr);
677 709 }
678 710
679 711 HeapWord* next;
680 712 while (cur < mr.end()) {
681 713 obj = oop(cur);
682 714 if (obj->klass_or_null() == NULL) {
683 715 // Ran into an unparseable point.
684 716 return cur;
685 717 };
686 718 // Otherwise:
687 719 next = (cur + obj->size());
688 720 if (!g1h->is_obj_dead(obj)) {
689 721 if (next < mr.end()) {
690 722 obj->oop_iterate(cl);
691 723 } else {
692 724 // this obj spans the boundary. If it's an array, stop at the
693 725 // boundary.
694 726 if (obj->is_objArray()) {
695 727 obj->oop_iterate(cl, mr);
696 728 } else {
697 729 obj->oop_iterate(cl);
698 730 }
699 731 }
700 732 }
701 733 cur = next;
702 734 }
703 735 return NULL;
704 736 }
705 737
706 738 void HeapRegion::print() const { print_on(gclog_or_tty); }
707 739 void HeapRegion::print_on(outputStream* st) const {
708 740 if (isHumongous()) {
709 741 if (startsHumongous())
710 742 st->print(" HS");
711 743 else
712 744 st->print(" HC");
713 745 } else {
714 746 st->print(" ");
715 747 }
716 748 if (in_collection_set())
717 749 st->print(" CS");
718 750 else
719 751 st->print(" ");
720 752 if (is_young())
721 753 st->print(is_survivor() ? " SU" : " Y ");
722 754 else
723 755 st->print(" ");
724 756 if (is_empty())
725 757 st->print(" F");
726 758 else
727 759 st->print(" ");
728 760 st->print(" %5d", _gc_time_stamp);
729 761 st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT,
730 762 prev_top_at_mark_start(), next_top_at_mark_start());
731 763 G1OffsetTableContigSpace::print_on(st);
732 764 }
733 765
734 766 void HeapRegion::verify(bool allow_dirty) const {
735 767 bool dummy = false;
736 768 verify(allow_dirty, VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
737 769 }
738 770
739 771 // This really ought to be commoned up into OffsetTableContigSpace somehow.
740 772 // We would need a mechanism to make that code skip dead objects.
741 773
742 774 void HeapRegion::verify(bool allow_dirty,
743 775 VerifyOption vo,
744 776 bool* failures) const {
745 777 G1CollectedHeap* g1 = G1CollectedHeap::heap();
746 778 *failures = false;
747 779 HeapWord* p = bottom();
748 780 HeapWord* prev_p = NULL;
749 781 VerifyLiveClosure vl_cl(g1, vo);
750 782 bool is_humongous = isHumongous();
751 783 bool do_bot_verify = !is_young();
752 784 size_t object_num = 0;
753 785 while (p < top()) {
754 786 oop obj = oop(p);
755 787 size_t obj_size = obj->size();
756 788 object_num += 1;
757 789
758 790 if (is_humongous != g1->isHumongous(obj_size)) {
759 791 gclog_or_tty->print_cr("obj "PTR_FORMAT" is of %shumongous size ("
760 792 SIZE_FORMAT" words) in a %shumongous region",
761 793 p, g1->isHumongous(obj_size) ? "" : "non-",
762 794 obj_size, is_humongous ? "" : "non-");
763 795 *failures = true;
764 796 return;
765 797 }
766 798
767 799 // If it returns false, verify_for_object() will output the
768 800 // appropriate messasge.
769 801 if (do_bot_verify && !_offsets.verify_for_object(p, obj_size)) {
770 802 *failures = true;
771 803 return;
772 804 }
773 805
774 806 if (!g1->is_obj_dead_cond(obj, this, vo)) {
775 807 if (obj->is_oop()) {
776 808 klassOop klass = obj->klass();
777 809 if (!klass->is_perm()) {
778 810 gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" "
779 811 "not in perm", klass, obj);
780 812 *failures = true;
781 813 return;
782 814 } else if (!klass->is_klass()) {
783 815 gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" "
784 816 "not a klass", klass, obj);
785 817 *failures = true;
786 818 return;
787 819 } else {
788 820 vl_cl.set_containing_obj(obj);
789 821 obj->oop_iterate(&vl_cl);
790 822 if (vl_cl.failures()) {
791 823 *failures = true;
792 824 }
793 825 if (G1MaxVerifyFailures >= 0 &&
794 826 vl_cl.n_failures() >= G1MaxVerifyFailures) {
795 827 return;
796 828 }
797 829 }
798 830 } else {
799 831 gclog_or_tty->print_cr(PTR_FORMAT" no an oop", obj);
800 832 *failures = true;
801 833 return;
802 834 }
803 835 }
804 836 prev_p = p;
805 837 p += obj_size;
806 838 }
807 839
808 840 if (p != top()) {
809 841 gclog_or_tty->print_cr("end of last object "PTR_FORMAT" "
810 842 "does not match top "PTR_FORMAT, p, top());
811 843 *failures = true;
812 844 return;
813 845 }
814 846
815 847 HeapWord* the_end = end();
816 848 assert(p == top(), "it should still hold");
817 849 // Do some extra BOT consistency checking for addresses in the
818 850 // range [top, end). BOT look-ups in this range should yield
819 851 // top. No point in doing that if top == end (there's nothing there).
820 852 if (p < the_end) {
821 853 // Look up top
822 854 HeapWord* addr_1 = p;
823 855 HeapWord* b_start_1 = _offsets.block_start_const(addr_1);
824 856 if (b_start_1 != p) {
825 857 gclog_or_tty->print_cr("BOT look up for top: "PTR_FORMAT" "
826 858 " yielded "PTR_FORMAT", expecting "PTR_FORMAT,
827 859 addr_1, b_start_1, p);
828 860 *failures = true;
829 861 return;
830 862 }
831 863
832 864 // Look up top + 1
833 865 HeapWord* addr_2 = p + 1;
834 866 if (addr_2 < the_end) {
835 867 HeapWord* b_start_2 = _offsets.block_start_const(addr_2);
836 868 if (b_start_2 != p) {
837 869 gclog_or_tty->print_cr("BOT look up for top + 1: "PTR_FORMAT" "
838 870 " yielded "PTR_FORMAT", expecting "PTR_FORMAT,
839 871 addr_2, b_start_2, p);
840 872 *failures = true;
841 873 return;
842 874 }
843 875 }
844 876
845 877 // Look up an address between top and end
846 878 size_t diff = pointer_delta(the_end, p) / 2;
847 879 HeapWord* addr_3 = p + diff;
848 880 if (addr_3 < the_end) {
849 881 HeapWord* b_start_3 = _offsets.block_start_const(addr_3);
850 882 if (b_start_3 != p) {
851 883 gclog_or_tty->print_cr("BOT look up for top + diff: "PTR_FORMAT" "
852 884 " yielded "PTR_FORMAT", expecting "PTR_FORMAT,
853 885 addr_3, b_start_3, p);
854 886 *failures = true;
855 887 return;
856 888 }
857 889 }
858 890
859 891 // Loook up end - 1
860 892 HeapWord* addr_4 = the_end - 1;
861 893 HeapWord* b_start_4 = _offsets.block_start_const(addr_4);
862 894 if (b_start_4 != p) {
863 895 gclog_or_tty->print_cr("BOT look up for end - 1: "PTR_FORMAT" "
864 896 " yielded "PTR_FORMAT", expecting "PTR_FORMAT,
865 897 addr_4, b_start_4, p);
866 898 *failures = true;
867 899 return;
868 900 }
869 901 }
870 902
871 903 if (is_humongous && object_num > 1) {
872 904 gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] is humongous "
873 905 "but has "SIZE_FORMAT", objects",
874 906 bottom(), end(), object_num);
875 907 *failures = true;
876 908 return;
877 909 }
878 910 }
879 911
880 912 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
881 913 // away eventually.
882 914
883 915 void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
884 916 // false ==> we'll do the clearing if there's clearing to be done.
885 917 ContiguousSpace::initialize(mr, false, mangle_space);
886 918 _offsets.zero_bottom_entry();
887 919 _offsets.initialize_threshold();
888 920 if (clear_space) clear(mangle_space);
889 921 }
890 922
891 923 void G1OffsetTableContigSpace::clear(bool mangle_space) {
892 924 ContiguousSpace::clear(mangle_space);
893 925 _offsets.zero_bottom_entry();
894 926 _offsets.initialize_threshold();
895 927 }
896 928
897 929 void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
898 930 Space::set_bottom(new_bottom);
899 931 _offsets.set_bottom(new_bottom);
900 932 }
901 933
902 934 void G1OffsetTableContigSpace::set_end(HeapWord* new_end) {
903 935 Space::set_end(new_end);
904 936 _offsets.resize(new_end - bottom());
905 937 }
906 938
907 939 void G1OffsetTableContigSpace::print() const {
908 940 print_short();
909 941 gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
910 942 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
911 943 bottom(), top(), _offsets.threshold(), end());
912 944 }
913 945
914 946 HeapWord* G1OffsetTableContigSpace::initialize_threshold() {
915 947 return _offsets.initialize_threshold();
916 948 }
917 949
918 950 HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start,
919 951 HeapWord* end) {
920 952 _offsets.alloc_block(start, end);
921 953 return _offsets.threshold();
922 954 }
923 955
924 956 HeapWord* G1OffsetTableContigSpace::saved_mark_word() const {
925 957 G1CollectedHeap* g1h = G1CollectedHeap::heap();
926 958 assert( _gc_time_stamp <= g1h->get_gc_time_stamp(), "invariant" );
927 959 if (_gc_time_stamp < g1h->get_gc_time_stamp())
928 960 return top();
929 961 else
930 962 return ContiguousSpace::saved_mark_word();
931 963 }
932 964
933 965 void G1OffsetTableContigSpace::set_saved_mark() {
934 966 G1CollectedHeap* g1h = G1CollectedHeap::heap();
935 967 unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp();
936 968
937 969 if (_gc_time_stamp < curr_gc_time_stamp) {
938 970 // The order of these is important, as another thread might be
939 971 // about to start scanning this region. If it does so after
940 972 // set_saved_mark and before _gc_time_stamp = ..., then the latter
941 973 // will be false, and it will pick up top() as the high water mark
942 974 // of region. If it does so after _gc_time_stamp = ..., then it
943 975 // will pick up the right saved_mark_word() as the high water mark
944 976 // of the region. Either way, the behaviour will be correct.
945 977 ContiguousSpace::set_saved_mark();
946 978 OrderAccess::storestore();
947 979 _gc_time_stamp = curr_gc_time_stamp;
948 980 // No need to do another barrier to flush the writes above. If
949 981 // this is called in parallel with other threads trying to
950 982 // allocate into the region, the caller should call this while
951 983 // holding a lock and when the lock is released the writes will be
952 984 // flushed.
953 985 }
954 986 }
955 987
956 988 G1OffsetTableContigSpace::
957 989 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
958 990 MemRegion mr, bool is_zeroed) :
959 991 _offsets(sharedOffsetArray, mr),
960 992 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
961 993 _gc_time_stamp(0)
962 994 {
963 995 _offsets.set_space(this);
964 996 initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
965 997 }
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