rev 10868 : [mq]: 8153170-card-live-data-does-handle-eager-reclaim
1 /* 2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "code/nmethod.hpp" 27 #include "gc/g1/g1BlockOffsetTable.inline.hpp" 28 #include "gc/g1/g1CollectedHeap.inline.hpp" 29 #include "gc/g1/g1HeapRegionTraceType.hpp" 30 #include "gc/g1/g1OopClosures.inline.hpp" 31 #include "gc/g1/heapRegion.inline.hpp" 32 #include "gc/g1/heapRegionBounds.inline.hpp" 33 #include "gc/g1/heapRegionManager.inline.hpp" 34 #include "gc/g1/heapRegionRemSet.hpp" 35 #include "gc/g1/heapRegionTracer.hpp" 36 #include "gc/shared/genOopClosures.inline.hpp" 37 #include "gc/shared/space.inline.hpp" 38 #include "logging/log.hpp" 39 #include "memory/iterator.hpp" 40 #include "memory/resourceArea.hpp" 41 #include "oops/oop.inline.hpp" 42 #include "runtime/atomic.inline.hpp" 43 #include "runtime/orderAccess.inline.hpp" 44 45 int HeapRegion::LogOfHRGrainBytes = 0; 46 int HeapRegion::LogOfHRGrainWords = 0; 47 size_t HeapRegion::GrainBytes = 0; 48 size_t HeapRegion::GrainWords = 0; 49 size_t HeapRegion::CardsPerRegion = 0; 50 51 HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1, 52 HeapRegion* hr, 53 G1ParPushHeapRSClosure* cl, 54 CardTableModRefBS::PrecisionStyle precision) : 55 DirtyCardToOopClosure(hr, cl, precision, NULL), 56 _hr(hr), _rs_scan(cl), _g1(g1) { } 57 58 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r, 59 OopClosure* oc) : 60 _r_bottom(r->bottom()), _r_end(r->end()), _oc(oc) { } 61 62 void HeapRegionDCTOC::walk_mem_region(MemRegion mr, 63 HeapWord* bottom, 64 HeapWord* top) { 65 G1CollectedHeap* g1h = _g1; 66 size_t oop_size; 67 HeapWord* cur = bottom; 68 69 // Start filtering what we add to the remembered set. If the object is 70 // not considered dead, either because it is marked (in the mark bitmap) 71 // or it was allocated after marking finished, then we add it. Otherwise 72 // we can safely ignore the object. 73 if (!g1h->is_obj_dead(oop(cur))) { 74 oop_size = oop(cur)->oop_iterate_size(_rs_scan, mr); 75 } else { 76 oop_size = _hr->block_size(cur); 77 } 78 79 cur += oop_size; 80 81 if (cur < top) { 82 oop cur_oop = oop(cur); 83 oop_size = _hr->block_size(cur); 84 HeapWord* next_obj = cur + oop_size; 85 while (next_obj < top) { 86 // Keep filtering the remembered set. 87 if (!g1h->is_obj_dead(cur_oop)) { 88 // Bottom lies entirely below top, so we can call the 89 // non-memRegion version of oop_iterate below. 90 cur_oop->oop_iterate(_rs_scan); 91 } 92 cur = next_obj; 93 cur_oop = oop(cur); 94 oop_size = _hr->block_size(cur); 95 next_obj = cur + oop_size; 96 } 97 98 // Last object. Need to do dead-obj filtering here too. 99 if (!g1h->is_obj_dead(oop(cur))) { 100 oop(cur)->oop_iterate(_rs_scan, mr); 101 } 102 } 103 } 104 105 size_t HeapRegion::max_region_size() { 106 return HeapRegionBounds::max_size(); 107 } 108 109 size_t HeapRegion::min_region_size_in_words() { 110 return HeapRegionBounds::min_size() >> LogHeapWordSize; 111 } 112 113 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) { 114 size_t region_size = G1HeapRegionSize; 115 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) { 116 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2; 117 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(), 118 HeapRegionBounds::min_size()); 119 } 120 121 int region_size_log = log2_long((jlong) region_size); 122 // Recalculate the region size to make sure it's a power of 123 // 2. This means that region_size is the largest power of 2 that's 124 // <= what we've calculated so far. 125 region_size = ((size_t)1 << region_size_log); 126 127 // Now make sure that we don't go over or under our limits. 128 if (region_size < HeapRegionBounds::min_size()) { 129 region_size = HeapRegionBounds::min_size(); 130 } else if (region_size > HeapRegionBounds::max_size()) { 131 region_size = HeapRegionBounds::max_size(); 132 } 133 134 // And recalculate the log. 135 region_size_log = log2_long((jlong) region_size); 136 137 // Now, set up the globals. 138 guarantee(LogOfHRGrainBytes == 0, "we should only set it once"); 139 LogOfHRGrainBytes = region_size_log; 140 141 guarantee(LogOfHRGrainWords == 0, "we should only set it once"); 142 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize; 143 144 guarantee(GrainBytes == 0, "we should only set it once"); 145 // The cast to int is safe, given that we've bounded region_size by 146 // MIN_REGION_SIZE and MAX_REGION_SIZE. 147 GrainBytes = region_size; 148 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M); 149 150 guarantee(GrainWords == 0, "we should only set it once"); 151 GrainWords = GrainBytes >> LogHeapWordSize; 152 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity"); 153 154 guarantee(CardsPerRegion == 0, "we should only set it once"); 155 CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift; 156 } 157 158 void HeapRegion::reset_after_compaction() { 159 G1ContiguousSpace::reset_after_compaction(); 160 // After a compaction the mark bitmap is invalid, so we must 161 // treat all objects as being inside the unmarked area. 162 zero_marked_bytes(); 163 init_top_at_mark_start(); 164 } 165 166 void HeapRegion::hr_clear(bool par, bool clear_space, bool locked) { 167 assert(_humongous_start_region == NULL, 168 "we should have already filtered out humongous regions"); 169 assert(!in_collection_set(), 170 "Should not clear heap region %u in the collection set", hrm_index()); 171 172 set_allocation_context(AllocationContext::system()); 173 set_young_index_in_cset(-1); 174 uninstall_surv_rate_group(); 175 set_free(); 176 reset_pre_dummy_top(); 177 178 if (!par) { 179 // If this is parallel, this will be done later. 180 HeapRegionRemSet* hrrs = rem_set(); 181 if (locked) { 182 hrrs->clear_locked(); 183 } else { 184 hrrs->clear(); 185 } 186 } 187 zero_marked_bytes(); 188 189 init_top_at_mark_start(); 190 _gc_time_stamp = G1CollectedHeap::heap()->get_gc_time_stamp(); 191 if (clear_space) clear(SpaceDecorator::Mangle); 192 } 193 194 void HeapRegion::par_clear() { 195 assert(used() == 0, "the region should have been already cleared"); 196 assert(capacity() == HeapRegion::GrainBytes, "should be back to normal"); 197 HeapRegionRemSet* hrrs = rem_set(); 198 hrrs->clear(); 199 CardTableModRefBS* ct_bs = 200 barrier_set_cast<CardTableModRefBS>(G1CollectedHeap::heap()->barrier_set()); 201 ct_bs->clear(MemRegion(bottom(), end())); 202 } 203 204 void HeapRegion::calc_gc_efficiency() { 205 // GC efficiency is the ratio of how much space would be 206 // reclaimed over how long we predict it would take to reclaim it. 207 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 208 G1CollectorPolicy* g1p = g1h->g1_policy(); 209 210 // Retrieve a prediction of the elapsed time for this region for 211 // a mixed gc because the region will only be evacuated during a 212 // mixed gc. 213 double region_elapsed_time_ms = 214 g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */); 215 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms; 216 } 217 218 void HeapRegion::set_free() { 219 report_region_type_change(G1HeapRegionTraceType::Free); 220 _type.set_free(); 221 } 222 223 void HeapRegion::set_eden() { 224 report_region_type_change(G1HeapRegionTraceType::Eden); 225 _type.set_eden(); 226 } 227 228 void HeapRegion::set_eden_pre_gc() { 229 report_region_type_change(G1HeapRegionTraceType::Eden); 230 _type.set_eden_pre_gc(); 231 } 232 233 void HeapRegion::set_survivor() { 234 report_region_type_change(G1HeapRegionTraceType::Survivor); 235 _type.set_survivor(); 236 } 237 238 void HeapRegion::set_old() { 239 report_region_type_change(G1HeapRegionTraceType::Old); 240 _type.set_old(); 241 } 242 243 void HeapRegion::set_archive() { 244 report_region_type_change(G1HeapRegionTraceType::Archive); 245 _type.set_archive(); 246 } 247 248 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) { 249 assert(!is_humongous(), "sanity / pre-condition"); 250 assert(top() == bottom(), "should be empty"); 251 252 report_region_type_change(G1HeapRegionTraceType::StartsHumongous); 253 _type.set_starts_humongous(); 254 _humongous_start_region = this; 255 256 _bot_part.set_for_starts_humongous(obj_top, fill_size); 257 } 258 259 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) { 260 assert(!is_humongous(), "sanity / pre-condition"); 261 assert(top() == bottom(), "should be empty"); 262 assert(first_hr->is_starts_humongous(), "pre-condition"); 263 264 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous); 265 _type.set_continues_humongous(); 266 _humongous_start_region = first_hr; 267 } 268 269 void HeapRegion::clear_humongous() { 270 assert(is_humongous(), "pre-condition"); 271 272 assert(capacity() == HeapRegion::GrainBytes, "pre-condition"); 273 _humongous_start_region = NULL; 274 } 275 276 HeapRegion::HeapRegion(uint hrm_index, 277 G1BlockOffsetTable* bot, 278 MemRegion mr) : 279 G1ContiguousSpace(bot), 280 _hrm_index(hrm_index), 281 _allocation_context(AllocationContext::system()), 282 _humongous_start_region(NULL), 283 _next_in_special_set(NULL), 284 _evacuation_failed(false), 285 _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0), 286 _next_young_region(NULL), 287 _next_dirty_cards_region(NULL), _next(NULL), _prev(NULL), 288 #ifdef ASSERT 289 _containing_set(NULL), 290 #endif // ASSERT 291 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1), 292 _rem_set(NULL), _recorded_rs_length(0), _predicted_elapsed_time_ms(0), 293 _predicted_bytes_to_copy(0) 294 { 295 _rem_set = new HeapRegionRemSet(bot, this); 296 297 initialize(mr); 298 } 299 300 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) { 301 assert(_rem_set->is_empty(), "Remembered set must be empty"); 302 303 G1ContiguousSpace::initialize(mr, clear_space, mangle_space); 304 305 hr_clear(false /*par*/, false /*clear_space*/); 306 set_top(bottom()); 307 record_timestamp(); 308 } 309 310 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) { 311 HeapRegionTracer::send_region_type_change(_hrm_index, 312 get_trace_type(), 313 to, 314 (uintptr_t)bottom(), 315 used(), 316 (uint)allocation_context()); 317 } 318 319 CompactibleSpace* HeapRegion::next_compaction_space() const { 320 return G1CollectedHeap::heap()->next_compaction_region(this); 321 } 322 323 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark, 324 bool during_conc_mark) { 325 // We always recreate the prev marking info and we'll explicitly 326 // mark all objects we find to be self-forwarded on the prev 327 // bitmap. So all objects need to be below PTAMS. 328 _prev_marked_bytes = 0; 329 330 if (during_initial_mark) { 331 // During initial-mark, we'll also explicitly mark all objects 332 // we find to be self-forwarded on the next bitmap. So all 333 // objects need to be below NTAMS. 334 _next_top_at_mark_start = top(); 335 _next_marked_bytes = 0; 336 } else if (during_conc_mark) { 337 // During concurrent mark, all objects in the CSet (including 338 // the ones we find to be self-forwarded) are implicitly live. 339 // So all objects need to be above NTAMS. 340 _next_top_at_mark_start = bottom(); 341 _next_marked_bytes = 0; 342 } 343 } 344 345 void HeapRegion::note_self_forwarding_removal_end(bool during_initial_mark, 346 bool during_conc_mark, 347 size_t marked_bytes) { 348 assert(marked_bytes <= used(), 349 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used()); 350 _prev_top_at_mark_start = top(); 351 _prev_marked_bytes = marked_bytes; 352 } 353 354 HeapWord* 355 HeapRegion::object_iterate_mem_careful(MemRegion mr, 356 ObjectClosure* cl) { 357 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 358 // We used to use "block_start_careful" here. But we're actually happy 359 // to update the BOT while we do this... 360 HeapWord* cur = block_start(mr.start()); 361 mr = mr.intersection(used_region()); 362 if (mr.is_empty()) return NULL; 363 // Otherwise, find the obj that extends onto mr.start(). 364 365 assert(cur <= mr.start() 366 && (oop(cur)->klass_or_null() == NULL || 367 cur + oop(cur)->size() > mr.start()), 368 "postcondition of block_start"); 369 oop obj; 370 while (cur < mr.end()) { 371 obj = oop(cur); 372 if (obj->klass_or_null() == NULL) { 373 // Ran into an unparseable point. 374 return cur; 375 } else if (!g1h->is_obj_dead(obj)) { 376 cl->do_object(obj); 377 } 378 cur += block_size(cur); 379 } 380 return NULL; 381 } 382 383 HeapWord* 384 HeapRegion:: 385 oops_on_card_seq_iterate_careful(MemRegion mr, 386 FilterOutOfRegionClosure* cl, 387 bool filter_young, 388 jbyte* card_ptr) { 389 // Currently, we should only have to clean the card if filter_young 390 // is true and vice versa. 391 if (filter_young) { 392 assert(card_ptr != NULL, "pre-condition"); 393 } else { 394 assert(card_ptr == NULL, "pre-condition"); 395 } 396 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 397 398 // If we're within a stop-world GC, then we might look at a card in a 399 // GC alloc region that extends onto a GC LAB, which may not be 400 // parseable. Stop such at the "scan_top" of the region. 401 if (g1h->is_gc_active()) { 402 mr = mr.intersection(MemRegion(bottom(), scan_top())); 403 } else { 404 mr = mr.intersection(used_region()); 405 } 406 if (mr.is_empty()) return NULL; 407 // Otherwise, find the obj that extends onto mr.start(). 408 409 // The intersection of the incoming mr (for the card) and the 410 // allocated part of the region is non-empty. This implies that 411 // we have actually allocated into this region. The code in 412 // G1CollectedHeap.cpp that allocates a new region sets the 413 // is_young tag on the region before allocating. Thus we 414 // safely know if this region is young. 415 if (is_young() && filter_young) { 416 return NULL; 417 } 418 419 assert(!is_young(), "check value of filter_young"); 420 421 // We can only clean the card here, after we make the decision that 422 // the card is not young. And we only clean the card if we have been 423 // asked to (i.e., card_ptr != NULL). 424 if (card_ptr != NULL) { 425 *card_ptr = CardTableModRefBS::clean_card_val(); 426 // We must complete this write before we do any of the reads below. 427 OrderAccess::storeload(); 428 } 429 430 // Cache the boundaries of the memory region in some const locals 431 HeapWord* const start = mr.start(); 432 HeapWord* const end = mr.end(); 433 434 // We used to use "block_start_careful" here. But we're actually happy 435 // to update the BOT while we do this... 436 HeapWord* cur = block_start(start); 437 assert(cur <= start, "Postcondition"); 438 439 oop obj; 440 441 HeapWord* next = cur; 442 do { 443 cur = next; 444 obj = oop(cur); 445 if (obj->klass_or_null() == NULL) { 446 // Ran into an unparseable point. 447 return cur; 448 } 449 // Otherwise... 450 next = cur + block_size(cur); 451 } while (next <= start); 452 453 // If we finish the above loop...We have a parseable object that 454 // begins on or before the start of the memory region, and ends 455 // inside or spans the entire region. 456 assert(cur <= start, "Loop postcondition"); 457 assert(obj->klass_or_null() != NULL, "Loop postcondition"); 458 459 do { 460 obj = oop(cur); 461 assert((cur + block_size(cur)) > (HeapWord*)obj, "Loop invariant"); 462 if (obj->klass_or_null() == NULL) { 463 // Ran into an unparseable point. 464 return cur; 465 } 466 467 // Advance the current pointer. "obj" still points to the object to iterate. 468 cur = cur + block_size(cur); 469 470 if (!g1h->is_obj_dead(obj)) { 471 // Non-objArrays are sometimes marked imprecise at the object start. We 472 // always need to iterate over them in full. 473 // We only iterate over object arrays in full if they are completely contained 474 // in the memory region. 475 if (!obj->is_objArray() || (((HeapWord*)obj) >= start && cur <= end)) { 476 obj->oop_iterate(cl); 477 } else { 478 obj->oop_iterate(cl, mr); 479 } 480 } 481 } while (cur < end); 482 483 return NULL; 484 } 485 486 // Code roots support 487 488 void HeapRegion::add_strong_code_root(nmethod* nm) { 489 HeapRegionRemSet* hrrs = rem_set(); 490 hrrs->add_strong_code_root(nm); 491 } 492 493 void HeapRegion::add_strong_code_root_locked(nmethod* nm) { 494 assert_locked_or_safepoint(CodeCache_lock); 495 HeapRegionRemSet* hrrs = rem_set(); 496 hrrs->add_strong_code_root_locked(nm); 497 } 498 499 void HeapRegion::remove_strong_code_root(nmethod* nm) { 500 HeapRegionRemSet* hrrs = rem_set(); 501 hrrs->remove_strong_code_root(nm); 502 } 503 504 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const { 505 HeapRegionRemSet* hrrs = rem_set(); 506 hrrs->strong_code_roots_do(blk); 507 } 508 509 class VerifyStrongCodeRootOopClosure: public OopClosure { 510 const HeapRegion* _hr; 511 nmethod* _nm; 512 bool _failures; 513 bool _has_oops_in_region; 514 515 template <class T> void do_oop_work(T* p) { 516 T heap_oop = oopDesc::load_heap_oop(p); 517 if (!oopDesc::is_null(heap_oop)) { 518 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 519 520 // Note: not all the oops embedded in the nmethod are in the 521 // current region. We only look at those which are. 522 if (_hr->is_in(obj)) { 523 // Object is in the region. Check that its less than top 524 if (_hr->top() <= (HeapWord*)obj) { 525 // Object is above top 526 log_error(gc, verify)("Object " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ") is above top " PTR_FORMAT, 527 p2i(obj), p2i(_hr->bottom()), p2i(_hr->end()), p2i(_hr->top())); 528 _failures = true; 529 return; 530 } 531 // Nmethod has at least one oop in the current region 532 _has_oops_in_region = true; 533 } 534 } 535 } 536 537 public: 538 VerifyStrongCodeRootOopClosure(const HeapRegion* hr, nmethod* nm): 539 _hr(hr), _failures(false), _has_oops_in_region(false) {} 540 541 void do_oop(narrowOop* p) { do_oop_work(p); } 542 void do_oop(oop* p) { do_oop_work(p); } 543 544 bool failures() { return _failures; } 545 bool has_oops_in_region() { return _has_oops_in_region; } 546 }; 547 548 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure { 549 const HeapRegion* _hr; 550 bool _failures; 551 public: 552 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) : 553 _hr(hr), _failures(false) {} 554 555 void do_code_blob(CodeBlob* cb) { 556 nmethod* nm = (cb == NULL) ? NULL : cb->as_nmethod_or_null(); 557 if (nm != NULL) { 558 // Verify that the nemthod is live 559 if (!nm->is_alive()) { 560 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots", 561 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 562 _failures = true; 563 } else { 564 VerifyStrongCodeRootOopClosure oop_cl(_hr, nm); 565 nm->oops_do(&oop_cl); 566 if (!oop_cl.has_oops_in_region()) { 567 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region", 568 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 569 _failures = true; 570 } else if (oop_cl.failures()) { 571 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT, 572 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 573 _failures = true; 574 } 575 } 576 } 577 } 578 579 bool failures() { return _failures; } 580 }; 581 582 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const { 583 if (!G1VerifyHeapRegionCodeRoots) { 584 // We're not verifying code roots. 585 return; 586 } 587 if (vo == VerifyOption_G1UseMarkWord) { 588 // Marking verification during a full GC is performed after class 589 // unloading, code cache unloading, etc so the strong code roots 590 // attached to each heap region are in an inconsistent state. They won't 591 // be consistent until the strong code roots are rebuilt after the 592 // actual GC. Skip verifying the strong code roots in this particular 593 // time. 594 assert(VerifyDuringGC, "only way to get here"); 595 return; 596 } 597 598 HeapRegionRemSet* hrrs = rem_set(); 599 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length(); 600 601 // if this region is empty then there should be no entries 602 // on its strong code root list 603 if (is_empty()) { 604 if (strong_code_roots_length > 0) { 605 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] is empty but has " SIZE_FORMAT " code root entries", 606 p2i(bottom()), p2i(end()), strong_code_roots_length); 607 *failures = true; 608 } 609 return; 610 } 611 612 if (is_continues_humongous()) { 613 if (strong_code_roots_length > 0) { 614 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries", 615 HR_FORMAT_PARAMS(this), strong_code_roots_length); 616 *failures = true; 617 } 618 return; 619 } 620 621 VerifyStrongCodeRootCodeBlobClosure cb_cl(this); 622 strong_code_roots_do(&cb_cl); 623 624 if (cb_cl.failures()) { 625 *failures = true; 626 } 627 } 628 629 void HeapRegion::print() const { print_on(tty); } 630 void HeapRegion::print_on(outputStream* st) const { 631 st->print("|%4u", this->_hrm_index); 632 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT, 633 p2i(bottom()), p2i(top()), p2i(end())); 634 st->print("|%3d%%", (int) ((double) used() * 100 / capacity())); 635 st->print("|%2s", get_short_type_str()); 636 if (in_collection_set()) { 637 st->print("|CS"); 638 } else { 639 st->print("| "); 640 } 641 st->print("|TS%3u", _gc_time_stamp); 642 st->print("|AC%3u", allocation_context()); 643 st->print_cr("|TAMS " PTR_FORMAT ", " PTR_FORMAT "|", 644 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start())); 645 } 646 647 class G1VerificationClosure : public OopClosure { 648 protected: 649 G1CollectedHeap* _g1h; 650 CardTableModRefBS* _bs; 651 oop _containing_obj; 652 bool _failures; 653 int _n_failures; 654 VerifyOption _vo; 655 public: 656 // _vo == UsePrevMarking -> use "prev" marking information, 657 // _vo == UseNextMarking -> use "next" marking information, 658 // _vo == UseMarkWord -> use mark word from object header. 659 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) : 660 _g1h(g1h), _bs(barrier_set_cast<CardTableModRefBS>(g1h->barrier_set())), 661 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) { 662 } 663 664 void set_containing_obj(oop obj) { 665 _containing_obj = obj; 666 } 667 668 bool failures() { return _failures; } 669 int n_failures() { return _n_failures; } 670 671 void print_object(outputStream* out, oop obj) { 672 #ifdef PRODUCT 673 Klass* k = obj->klass(); 674 const char* class_name = k->external_name(); 675 out->print_cr("class name %s", class_name); 676 #else // PRODUCT 677 obj->print_on(out); 678 #endif // PRODUCT 679 } 680 }; 681 682 class VerifyLiveClosure : public G1VerificationClosure { 683 public: 684 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 685 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 686 virtual void do_oop(oop* p) { do_oop_work(p); } 687 688 template <class T> 689 void do_oop_work(T* p) { 690 assert(_containing_obj != NULL, "Precondition"); 691 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 692 "Precondition"); 693 verify_liveness(p); 694 } 695 696 template <class T> 697 void verify_liveness(T* p) { 698 T heap_oop = oopDesc::load_heap_oop(p); 699 Log(gc, verify) log; 700 if (!oopDesc::is_null(heap_oop)) { 701 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 702 bool failed = false; 703 if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead_cond(obj, _vo)) { 704 MutexLockerEx x(ParGCRareEvent_lock, 705 Mutex::_no_safepoint_check_flag); 706 707 if (!_failures) { 708 log.error("----------"); 709 } 710 ResourceMark rm; 711 if (!_g1h->is_in_closed_subset(obj)) { 712 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 713 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 714 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end())); 715 print_object(log.error_stream(), _containing_obj); 716 log.error("points to obj " PTR_FORMAT " not in the heap", p2i(obj)); 717 } else { 718 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 719 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj); 720 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 721 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end())); 722 print_object(log.error_stream(), _containing_obj); 723 log.error("points to dead obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 724 p2i(obj), p2i(to->bottom()), p2i(to->end())); 725 print_object(log.error_stream(), obj); 726 } 727 log.error("----------"); 728 _failures = true; 729 failed = true; 730 _n_failures++; 731 } 732 } 733 } 734 }; 735 736 class VerifyRemSetClosure : public G1VerificationClosure { 737 public: 738 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 739 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 740 virtual void do_oop(oop* p) { do_oop_work(p); } 741 742 template <class T> 743 void do_oop_work(T* p) { 744 assert(_containing_obj != NULL, "Precondition"); 745 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 746 "Precondition"); 747 verify_remembered_set(p); 748 } 749 750 template <class T> 751 void verify_remembered_set(T* p) { 752 T heap_oop = oopDesc::load_heap_oop(p); 753 Log(gc, verify) log; 754 if (!oopDesc::is_null(heap_oop)) { 755 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 756 bool failed = false; 757 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 758 HeapRegion* to = _g1h->heap_region_containing(obj); 759 if (from != NULL && to != NULL && 760 from != to && 761 !to->is_pinned()) { 762 jbyte cv_obj = *_bs->byte_for_const(_containing_obj); 763 jbyte cv_field = *_bs->byte_for_const(p); 764 const jbyte dirty = CardTableModRefBS::dirty_card_val(); 765 766 bool is_bad = !(from->is_young() 767 || to->rem_set()->contains_reference(p) 768 || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed 769 (_containing_obj->is_objArray() ? 770 cv_field == dirty 771 : cv_obj == dirty || cv_field == dirty)); 772 if (is_bad) { 773 MutexLockerEx x(ParGCRareEvent_lock, 774 Mutex::_no_safepoint_check_flag); 775 776 if (!_failures) { 777 log.error("----------"); 778 } 779 log.error("Missing rem set entry:"); 780 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT ", in region " HR_FORMAT, 781 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from)); 782 ResourceMark rm; 783 _containing_obj->print_on(log.error_stream()); 784 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT, p2i(obj), HR_FORMAT_PARAMS(to)); 785 if (obj->is_oop()) { 786 obj->print_on(log.error_stream()); 787 } 788 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field); 789 log.error("----------"); 790 _failures = true; 791 if (!failed) _n_failures++; 792 } 793 } 794 } 795 } 796 }; 797 798 // This really ought to be commoned up into OffsetTableContigSpace somehow. 799 // We would need a mechanism to make that code skip dead objects. 800 801 void HeapRegion::verify(VerifyOption vo, 802 bool* failures) const { 803 G1CollectedHeap* g1 = G1CollectedHeap::heap(); 804 *failures = false; 805 HeapWord* p = bottom(); 806 HeapWord* prev_p = NULL; 807 VerifyLiveClosure vl_cl(g1, vo); 808 VerifyRemSetClosure vr_cl(g1, vo); 809 bool is_region_humongous = is_humongous(); 810 size_t object_num = 0; 811 while (p < top()) { 812 oop obj = oop(p); 813 size_t obj_size = block_size(p); 814 object_num += 1; 815 816 if (!g1->is_obj_dead_cond(obj, this, vo)) { 817 if (obj->is_oop()) { 818 Klass* klass = obj->klass(); 819 bool is_metaspace_object = Metaspace::contains(klass) || 820 (vo == VerifyOption_G1UsePrevMarking && 821 ClassLoaderDataGraph::unload_list_contains(klass)); 822 if (!is_metaspace_object) { 823 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 824 "not metadata", p2i(klass), p2i(obj)); 825 *failures = true; 826 return; 827 } else if (!klass->is_klass()) { 828 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 829 "not a klass", p2i(klass), p2i(obj)); 830 *failures = true; 831 return; 832 } else { 833 vl_cl.set_containing_obj(obj); 834 if (!g1->collector_state()->full_collection() || G1VerifyRSetsDuringFullGC) { 835 // verify liveness and rem_set 836 vr_cl.set_containing_obj(obj); 837 G1Mux2Closure mux(&vl_cl, &vr_cl); 838 obj->oop_iterate_no_header(&mux); 839 840 if (vr_cl.failures()) { 841 *failures = true; 842 } 843 if (G1MaxVerifyFailures >= 0 && 844 vr_cl.n_failures() >= G1MaxVerifyFailures) { 845 return; 846 } 847 } else { 848 // verify only liveness 849 obj->oop_iterate_no_header(&vl_cl); 850 } 851 if (vl_cl.failures()) { 852 *failures = true; 853 } 854 if (G1MaxVerifyFailures >= 0 && 855 vl_cl.n_failures() >= G1MaxVerifyFailures) { 856 return; 857 } 858 } 859 } else { 860 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 861 *failures = true; 862 return; 863 } 864 } 865 prev_p = p; 866 p += obj_size; 867 } 868 869 if (!is_young() && !is_empty()) { 870 _bot_part.verify(); 871 } 872 873 if (is_region_humongous) { 874 oop obj = oop(this->humongous_start_region()->bottom()); 875 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) { 876 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj)); 877 *failures = true; 878 return; 879 } 880 } 881 882 if (!is_region_humongous && p != top()) { 883 log_error(gc, verify)("end of last object " PTR_FORMAT " " 884 "does not match top " PTR_FORMAT, p2i(p), p2i(top())); 885 *failures = true; 886 return; 887 } 888 889 HeapWord* the_end = end(); 890 // Do some extra BOT consistency checking for addresses in the 891 // range [top, end). BOT look-ups in this range should yield 892 // top. No point in doing that if top == end (there's nothing there). 893 if (p < the_end) { 894 // Look up top 895 HeapWord* addr_1 = p; 896 HeapWord* b_start_1 = _bot_part.block_start_const(addr_1); 897 if (b_start_1 != p) { 898 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " " 899 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 900 p2i(addr_1), p2i(b_start_1), p2i(p)); 901 *failures = true; 902 return; 903 } 904 905 // Look up top + 1 906 HeapWord* addr_2 = p + 1; 907 if (addr_2 < the_end) { 908 HeapWord* b_start_2 = _bot_part.block_start_const(addr_2); 909 if (b_start_2 != p) { 910 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " " 911 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 912 p2i(addr_2), p2i(b_start_2), p2i(p)); 913 *failures = true; 914 return; 915 } 916 } 917 918 // Look up an address between top and end 919 size_t diff = pointer_delta(the_end, p) / 2; 920 HeapWord* addr_3 = p + diff; 921 if (addr_3 < the_end) { 922 HeapWord* b_start_3 = _bot_part.block_start_const(addr_3); 923 if (b_start_3 != p) { 924 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " " 925 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 926 p2i(addr_3), p2i(b_start_3), p2i(p)); 927 *failures = true; 928 return; 929 } 930 } 931 932 // Look up end - 1 933 HeapWord* addr_4 = the_end - 1; 934 HeapWord* b_start_4 = _bot_part.block_start_const(addr_4); 935 if (b_start_4 != p) { 936 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " " 937 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 938 p2i(addr_4), p2i(b_start_4), p2i(p)); 939 *failures = true; 940 return; 941 } 942 } 943 944 verify_strong_code_roots(vo, failures); 945 } 946 947 void HeapRegion::verify() const { 948 bool dummy = false; 949 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy); 950 } 951 952 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const { 953 G1CollectedHeap* g1 = G1CollectedHeap::heap(); 954 *failures = false; 955 HeapWord* p = bottom(); 956 HeapWord* prev_p = NULL; 957 VerifyRemSetClosure vr_cl(g1, vo); 958 while (p < top()) { 959 oop obj = oop(p); 960 size_t obj_size = block_size(p); 961 962 if (!g1->is_obj_dead_cond(obj, this, vo)) { 963 if (obj->is_oop()) { 964 vr_cl.set_containing_obj(obj); 965 obj->oop_iterate_no_header(&vr_cl); 966 967 if (vr_cl.failures()) { 968 *failures = true; 969 } 970 if (G1MaxVerifyFailures >= 0 && 971 vr_cl.n_failures() >= G1MaxVerifyFailures) { 972 return; 973 } 974 } else { 975 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 976 *failures = true; 977 return; 978 } 979 } 980 981 prev_p = p; 982 p += obj_size; 983 } 984 } 985 986 void HeapRegion::verify_rem_set() const { 987 bool failures = false; 988 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures); 989 guarantee(!failures, "HeapRegion RemSet verification failed"); 990 } 991 992 void HeapRegion::prepare_for_compaction(CompactPoint* cp) { 993 scan_and_forward(this, cp); 994 } 995 996 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go 997 // away eventually. 998 999 void G1ContiguousSpace::clear(bool mangle_space) { 1000 set_top(bottom()); 1001 _scan_top = bottom(); 1002 CompactibleSpace::clear(mangle_space); 1003 reset_bot(); 1004 } 1005 1006 #ifndef PRODUCT 1007 void G1ContiguousSpace::mangle_unused_area() { 1008 mangle_unused_area_complete(); 1009 } 1010 1011 void G1ContiguousSpace::mangle_unused_area_complete() { 1012 SpaceMangler::mangle_region(MemRegion(top(), end())); 1013 } 1014 #endif 1015 1016 void G1ContiguousSpace::print() const { 1017 print_short(); 1018 tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " 1019 INTPTR_FORMAT ", " INTPTR_FORMAT ")", 1020 p2i(bottom()), p2i(top()), p2i(_bot_part.threshold()), p2i(end())); 1021 } 1022 1023 HeapWord* G1ContiguousSpace::initialize_threshold() { 1024 return _bot_part.initialize_threshold(); 1025 } 1026 1027 HeapWord* G1ContiguousSpace::cross_threshold(HeapWord* start, 1028 HeapWord* end) { 1029 _bot_part.alloc_block(start, end); 1030 return _bot_part.threshold(); 1031 } 1032 1033 HeapWord* G1ContiguousSpace::scan_top() const { 1034 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1035 HeapWord* local_top = top(); 1036 OrderAccess::loadload(); 1037 const unsigned local_time_stamp = _gc_time_stamp; 1038 assert(local_time_stamp <= g1h->get_gc_time_stamp(), "invariant"); 1039 if (local_time_stamp < g1h->get_gc_time_stamp()) { 1040 return local_top; 1041 } else { 1042 return _scan_top; 1043 } 1044 } 1045 1046 void G1ContiguousSpace::record_timestamp() { 1047 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1048 uint curr_gc_time_stamp = g1h->get_gc_time_stamp(); 1049 1050 if (_gc_time_stamp < curr_gc_time_stamp) { 1051 // Setting the time stamp here tells concurrent readers to look at 1052 // scan_top to know the maximum allowed address to look at. 1053 1054 // scan_top should be bottom for all regions except for the 1055 // retained old alloc region which should have scan_top == top 1056 HeapWord* st = _scan_top; 1057 guarantee(st == _bottom || st == _top, "invariant"); 1058 1059 _gc_time_stamp = curr_gc_time_stamp; 1060 } 1061 } 1062 1063 void G1ContiguousSpace::record_retained_region() { 1064 // scan_top is the maximum address where it's safe for the next gc to 1065 // scan this region. 1066 _scan_top = top(); 1067 } 1068 1069 void G1ContiguousSpace::safe_object_iterate(ObjectClosure* blk) { 1070 object_iterate(blk); 1071 } 1072 1073 void G1ContiguousSpace::object_iterate(ObjectClosure* blk) { 1074 HeapWord* p = bottom(); 1075 while (p < top()) { 1076 if (block_is_obj(p)) { 1077 blk->do_object(oop(p)); 1078 } 1079 p += block_size(p); 1080 } 1081 } 1082 1083 G1ContiguousSpace::G1ContiguousSpace(G1BlockOffsetTable* bot) : 1084 _bot_part(bot, this), 1085 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true), 1086 _gc_time_stamp(0) 1087 { 1088 } 1089 1090 void G1ContiguousSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) { 1091 CompactibleSpace::initialize(mr, clear_space, mangle_space); 1092 _top = bottom(); 1093 _scan_top = bottom(); 1094 set_saved_mark_word(NULL); 1095 reset_bot(); 1096 } 1097 --- EOF ---