1 /* 2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #include "memory/allocation.hpp" 25 26 #include "gc/shared/gcTimer.hpp" 27 #include "gc/shared/gcTraceTime.inline.hpp" 28 #include "gc/shared/parallelCleaning.hpp" 29 30 #include "gc/shenandoah/brooksPointer.hpp" 31 #include "gc/shenandoah/shenandoahBarrierSet.hpp" 32 #include "gc/shenandoah/shenandoahCollectionSet.hpp" 33 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp" 34 #include "gc/shenandoah/shenandoahConcurrentMark.hpp" 35 #include "gc/shenandoah/shenandoahConcurrentMark.inline.hpp" 36 #include "gc/shenandoah/shenandoahConcurrentThread.hpp" 37 #include "gc/shenandoah/shenandoahFreeSet.hpp" 38 #include "gc/shenandoah/shenandoahHeap.inline.hpp" 39 #include "gc/shenandoah/shenandoahHeapRegion.hpp" 40 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp" 41 #include "gc/shenandoah/shenandoahHumongous.hpp" 42 #include "gc/shenandoah/shenandoahMarkCompact.hpp" 43 #include "gc/shenandoah/shenandoahMonitoringSupport.hpp" 44 #include "gc/shenandoah/shenandoahRootProcessor.hpp" 45 #include "gc/shenandoah/vm_operations_shenandoah.hpp" 46 47 #include "runtime/vmThread.hpp" 48 #include "services/mallocTracker.hpp" 49 50 SCMUpdateRefsClosure::SCMUpdateRefsClosure() : _heap(ShenandoahHeap::heap()) {} 51 52 #ifdef ASSERT 53 template <class T> 54 void AssertToSpaceClosure::do_oop_nv(T* p) { 55 T o = oopDesc::load_heap_oop(p); 56 if (! oopDesc::is_null(o)) { 57 oop obj = oopDesc::decode_heap_oop_not_null(o); 58 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), 59 "need to-space object here obj: "PTR_FORMAT" , rb(obj): "PTR_FORMAT", p: "PTR_FORMAT, 60 p2i(obj), p2i(ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), p2i(p)); 61 } 62 } 63 64 void AssertToSpaceClosure::do_oop(narrowOop* p) { do_oop_nv(p); } 65 void AssertToSpaceClosure::do_oop(oop* p) { do_oop_nv(p); } 66 #endif 67 68 const char* ShenandoahHeap::name() const { 69 return "Shenandoah"; 70 } 71 72 void ShenandoahHeap::print_heap_locations(HeapWord* start, HeapWord* end) { 73 HeapWord* cur = NULL; 74 for (cur = start; cur < end; cur++) { 75 tty->print_cr(PTR_FORMAT" : "PTR_FORMAT, p2i(cur), p2i(*((HeapWord**) cur))); 76 } 77 } 78 79 class PrintHeapRegionsClosure : public 80 ShenandoahHeapRegionClosure { 81 private: 82 outputStream* _st; 83 public: 84 PrintHeapRegionsClosure() : _st(tty) {} 85 PrintHeapRegionsClosure(outputStream* st) : _st(st) {} 86 87 bool doHeapRegion(ShenandoahHeapRegion* r) { 88 r->print_on(_st); 89 return false; 90 } 91 }; 92 93 class ShenandoahPretouchTask : public AbstractGangTask { 94 private: 95 ShenandoahHeapRegionSet* _regions; 96 const size_t _bitmap_size; 97 const size_t _page_size; 98 char* _bitmap0_base; 99 char* _bitmap1_base; 100 public: 101 ShenandoahPretouchTask(ShenandoahHeapRegionSet* regions, 102 char* bitmap0_base, char* bitmap1_base, size_t bitmap_size, 103 size_t page_size) : 104 AbstractGangTask("Shenandoah PreTouch", 105 Universe::is_fully_initialized() ? GCId::current_raw() : 106 // During VM initialization there is 107 // no GC cycle that this task can be 108 // associated with. 109 GCId::undefined()), 110 _bitmap0_base(bitmap0_base), 111 _bitmap1_base(bitmap1_base), 112 _regions(regions), 113 _bitmap_size(bitmap_size), 114 _page_size(page_size) { 115 _regions->clear_current_index(); 116 }; 117 118 virtual void work(uint worker_id) { 119 ShenandoahHeapRegion* r = _regions->claim_next(); 120 while (r != NULL) { 121 log_trace(gc, heap)("Pretouch region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT, 122 r->region_number(), p2i(r->bottom()), p2i(r->end())); 123 os::pretouch_memory(r->bottom(), r->end(), _page_size); 124 125 size_t start = r->region_number() * ShenandoahHeapRegion::RegionSizeBytes / CMBitMap::heap_map_factor(); 126 size_t end = (r->region_number() + 1) * ShenandoahHeapRegion::RegionSizeBytes / CMBitMap::heap_map_factor(); 127 assert (end <= _bitmap_size, "end is sane: " SIZE_FORMAT " < " SIZE_FORMAT, end, _bitmap_size); 128 129 log_trace(gc, heap)("Pretouch bitmap under region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT, 130 r->region_number(), p2i(_bitmap0_base + start), p2i(_bitmap0_base + end)); 131 os::pretouch_memory(_bitmap0_base + start, _bitmap0_base + end, _page_size); 132 133 log_trace(gc, heap)("Pretouch bitmap under region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT, 134 r->region_number(), p2i(_bitmap1_base + start), p2i(_bitmap1_base + end)); 135 os::pretouch_memory(_bitmap1_base + start, _bitmap1_base + end, _page_size); 136 137 r = _regions->claim_next(); 138 } 139 } 140 }; 141 142 jint ShenandoahHeap::initialize() { 143 CollectedHeap::pre_initialize(); 144 145 size_t init_byte_size = collector_policy()->initial_heap_byte_size(); 146 size_t max_byte_size = collector_policy()->max_heap_byte_size(); 147 148 Universe::check_alignment(max_byte_size, 149 ShenandoahHeapRegion::RegionSizeBytes, 150 "shenandoah heap"); 151 Universe::check_alignment(init_byte_size, 152 ShenandoahHeapRegion::RegionSizeBytes, 153 "shenandoah heap"); 154 155 ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size, 156 Arguments::conservative_max_heap_alignment()); 157 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*) (heap_rs.base() + heap_rs.size())); 158 159 set_barrier_set(new ShenandoahBarrierSet(this)); 160 ReservedSpace pgc_rs = heap_rs.first_part(max_byte_size); 161 _storage.initialize(pgc_rs, init_byte_size); 162 163 _num_regions = init_byte_size / ShenandoahHeapRegion::RegionSizeBytes; 164 _max_regions = max_byte_size / ShenandoahHeapRegion::RegionSizeBytes; 165 _initialSize = _num_regions * ShenandoahHeapRegion::RegionSizeBytes; 166 size_t regionSizeWords = ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize; 167 assert(init_byte_size == _initialSize, "tautology"); 168 _ordered_regions = new ShenandoahHeapRegionSet(_max_regions); 169 _collection_set = new ShenandoahCollectionSet(_max_regions); 170 _free_regions = new ShenandoahFreeSet(_max_regions); 171 172 // Initialize fast collection set test structure. 173 _in_cset_fast_test_length = _max_regions; 174 _in_cset_fast_test_base = 175 NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length, mtGC); 176 _in_cset_fast_test = _in_cset_fast_test_base - 177 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift); 178 179 _next_top_at_mark_starts_base = 180 NEW_C_HEAP_ARRAY(HeapWord*, _max_regions, mtGC); 181 _next_top_at_mark_starts = _next_top_at_mark_starts_base - 182 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift); 183 184 _complete_top_at_mark_starts_base = 185 NEW_C_HEAP_ARRAY(HeapWord*, _max_regions, mtGC); 186 _complete_top_at_mark_starts = _complete_top_at_mark_starts_base - 187 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift); 188 189 size_t i = 0; 190 for (i = 0; i < _num_regions; i++) { 191 _in_cset_fast_test_base[i] = false; // Not in cset 192 HeapWord* bottom = (HeapWord*) pgc_rs.base() + regionSizeWords * i; 193 _complete_top_at_mark_starts_base[i] = bottom; 194 _next_top_at_mark_starts_base[i] = bottom; 195 } 196 197 { 198 ShenandoahHeapLock lock(this); 199 for (i = 0; i < _num_regions; i++) { 200 ShenandoahHeapRegion* current = new ShenandoahHeapRegion(this, (HeapWord*) pgc_rs.base() + 201 regionSizeWords * i, regionSizeWords, i); 202 _free_regions->add_region(current); 203 _ordered_regions->add_region(current); 204 } 205 } 206 assert(((size_t) _ordered_regions->active_regions()) == _num_regions, ""); 207 _first_region = _ordered_regions->get(0); 208 _first_region_bottom = _first_region->bottom(); 209 assert((((size_t) _first_region_bottom) & 210 (ShenandoahHeapRegion::RegionSizeBytes - 1)) == 0, 211 "misaligned heap: "PTR_FORMAT, p2i(_first_region_bottom)); 212 213 _numAllocs = 0; 214 215 if (log_is_enabled(Trace, gc, region)) { 216 ResourceMark rm; 217 outputStream* out = Log(gc, region)::trace_stream(); 218 log_trace(gc, region)("All Regions"); 219 _ordered_regions->print(out); 220 log_trace(gc, region)("Free Regions"); 221 _free_regions->print(out); 222 } 223 224 // The call below uses stuff (the SATB* things) that are in G1, but probably 225 // belong into a shared location. 226 JavaThread::satb_mark_queue_set().initialize(SATB_Q_CBL_mon, 227 SATB_Q_FL_lock, 228 20 /*G1SATBProcessCompletedThreshold */, 229 Shared_SATB_Q_lock); 230 231 // Reserve space for prev and next bitmap. 232 size_t bitmap_size = CMBitMap::compute_size(heap_rs.size()); 233 MemRegion heap_region = MemRegion((HeapWord*) heap_rs.base(), heap_rs.size() / HeapWordSize); 234 235 size_t page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size(); 236 237 ReservedSpace bitmap0(bitmap_size, page_size); 238 os::commit_memory_or_exit(bitmap0.base(), bitmap0.size(), false, "couldn't allocate mark bitmap"); 239 MemTracker::record_virtual_memory_type(bitmap0.base(), mtGC); 240 MemRegion bitmap_region0 = MemRegion((HeapWord*) bitmap0.base(), bitmap0.size() / HeapWordSize); 241 242 ReservedSpace bitmap1(bitmap_size, page_size); 243 os::commit_memory_or_exit(bitmap1.base(), bitmap1.size(), false, "couldn't allocate mark bitmap"); 244 MemTracker::record_virtual_memory_type(bitmap1.base(), mtGC); 245 MemRegion bitmap_region1 = MemRegion((HeapWord*) bitmap1.base(), bitmap1.size() / HeapWordSize); 246 247 if (ShenandoahAlwaysPreTouch) { 248 assert (!AlwaysPreTouch, "Should have been overridden"); 249 250 // For NUMA, it is important to pre-touch the storage under bitmaps with worker threads, 251 // before initialize() below zeroes it with initializing thread. For any given region, 252 // we touch the region and the corresponding bitmaps from the same thread. 253 254 log_info(gc, heap)("Parallel pretouch " SIZE_FORMAT " regions with " SIZE_FORMAT " byte pages", 255 _ordered_regions->count(), page_size); 256 ShenandoahPretouchTask cl(_ordered_regions, bitmap0.base(), bitmap1.base(), bitmap_size, page_size); 257 _workers->run_task(&cl); 258 } 259 260 _mark_bit_map0.initialize(heap_region, bitmap_region0); 261 _complete_mark_bit_map = &_mark_bit_map0; 262 263 _mark_bit_map1.initialize(heap_region, bitmap_region1); 264 _next_mark_bit_map = &_mark_bit_map1; 265 266 _connection_matrix = new ShenandoahConnectionMatrix(_max_regions); 267 268 _monitoring_support = new ShenandoahMonitoringSupport(this); 269 270 _concurrent_gc_thread = new ShenandoahConcurrentThread(); 271 272 ShenandoahMarkCompact::initialize(); 273 274 return JNI_OK; 275 } 276 277 ShenandoahHeap::ShenandoahHeap(ShenandoahCollectorPolicy* policy) : 278 CollectedHeap(), 279 _shenandoah_policy(policy), 280 _concurrent_mark_in_progress(0), 281 _evacuation_in_progress(0), 282 _full_gc_in_progress(false), 283 _free_regions(NULL), 284 _collection_set(NULL), 285 _bytes_allocated_since_cm(0), 286 _bytes_allocated_during_cm(0), 287 _max_allocated_gc(0), 288 _allocated_last_gc(0), 289 _used_start_gc(0), 290 _max_workers(MAX2(ConcGCThreads, ParallelGCThreads)), 291 _ref_processor(NULL), 292 _in_cset_fast_test(NULL), 293 _in_cset_fast_test_base(NULL), 294 _next_top_at_mark_starts(NULL), 295 _next_top_at_mark_starts_base(NULL), 296 _complete_top_at_mark_starts(NULL), 297 _complete_top_at_mark_starts_base(NULL), 298 _mark_bit_map0(), 299 _mark_bit_map1(), 300 _connection_matrix(NULL), 301 _cancelled_concgc(false), 302 _need_update_refs(false), 303 _need_reset_bitmaps(false), 304 _heap_lock(0), 305 #ifdef ASSERT 306 _heap_lock_owner(NULL), 307 #endif 308 _gc_timer(new (ResourceObj::C_HEAP, mtGC) ConcurrentGCTimer()) 309 310 { 311 log_info(gc, init)("Parallel GC threads: "UINT32_FORMAT, ParallelGCThreads); 312 log_info(gc, init)("Concurrent GC threads: "UINT32_FORMAT, ConcGCThreads); 313 log_info(gc, init)("Parallel reference processing enabled: %s", BOOL_TO_STR(ParallelRefProcEnabled)); 314 315 _scm = new ShenandoahConcurrentMark(); 316 _used = 0; 317 318 _max_workers = MAX2(_max_workers, 1U); 319 _workers = new ShenandoahWorkGang("Shenandoah GC Threads", _max_workers, 320 /* are_GC_task_threads */true, 321 /* are_ConcurrentGC_threads */false); 322 if (_workers == NULL) { 323 vm_exit_during_initialization("Failed necessary allocation."); 324 } else { 325 _workers->initialize_workers(); 326 } 327 } 328 329 class ResetNextBitmapTask : public AbstractGangTask { 330 private: 331 ShenandoahHeapRegionSet* _regions; 332 333 public: 334 ResetNextBitmapTask(ShenandoahHeapRegionSet* regions) : 335 AbstractGangTask("Parallel Reset Bitmap Task"), 336 _regions(regions) { 337 _regions->clear_current_index(); 338 } 339 340 void work(uint worker_id) { 341 ShenandoahHeapRegion* region = _regions->claim_next(); 342 ShenandoahHeap* heap = ShenandoahHeap::heap(); 343 while (region != NULL) { 344 HeapWord* bottom = region->bottom(); 345 HeapWord* top = heap->next_top_at_mark_start(region->bottom()); 346 if (top > bottom) { 347 heap->next_mark_bit_map()->clear_range_large(MemRegion(bottom, top)); 348 } 349 region = _regions->claim_next(); 350 } 351 } 352 }; 353 354 void ShenandoahHeap::reset_next_mark_bitmap(WorkGang* workers) { 355 ResetNextBitmapTask task = ResetNextBitmapTask(_ordered_regions); 356 workers->run_task(&task); 357 } 358 359 class ResetCompleteBitmapTask : public AbstractGangTask { 360 private: 361 ShenandoahHeapRegionSet* _regions; 362 363 public: 364 ResetCompleteBitmapTask(ShenandoahHeapRegionSet* regions) : 365 AbstractGangTask("Parallel Reset Bitmap Task"), 366 _regions(regions) { 367 _regions->clear_current_index(); 368 } 369 370 void work(uint worker_id) { 371 ShenandoahHeapRegion* region = _regions->claim_next(); 372 ShenandoahHeap* heap = ShenandoahHeap::heap(); 373 while (region != NULL) { 374 HeapWord* bottom = region->bottom(); 375 HeapWord* top = heap->complete_top_at_mark_start(region->bottom()); 376 if (top > bottom) { 377 heap->complete_mark_bit_map()->clear_range_large(MemRegion(bottom, top)); 378 } 379 region = _regions->claim_next(); 380 } 381 } 382 }; 383 384 void ShenandoahHeap::reset_complete_mark_bitmap(WorkGang* workers) { 385 ResetCompleteBitmapTask task = ResetCompleteBitmapTask(_ordered_regions); 386 workers->run_task(&task); 387 } 388 389 bool ShenandoahHeap::is_next_bitmap_clear() { 390 HeapWord* start = _ordered_regions->bottom(); 391 HeapWord* end = _ordered_regions->end(); 392 return _next_mark_bit_map->getNextMarkedWordAddress(start, end) == end; 393 } 394 395 bool ShenandoahHeap::is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end) { 396 return _complete_mark_bit_map->getNextMarkedWordAddress(start, end) == end; 397 } 398 399 void ShenandoahHeap::print_on(outputStream* st) const { 400 st->print("Shenandoah Heap"); 401 st->print(" total = " SIZE_FORMAT " K, used " SIZE_FORMAT " K ", capacity()/ K, used() /K); 402 st->print(" [" PTR_FORMAT ", " PTR_FORMAT ") ", 403 p2i(reserved_region().start()), 404 p2i(reserved_region().end())); 405 st->print("Region size = " SIZE_FORMAT "K ", ShenandoahHeapRegion::RegionSizeBytes / K); 406 if (_concurrent_mark_in_progress) { 407 st->print("marking "); 408 } 409 if (_evacuation_in_progress) { 410 st->print("evacuating "); 411 } 412 if (cancelled_concgc()) { 413 st->print("cancelled "); 414 } 415 st->print("\n"); 416 417 // Adapted from VirtualSpace::print_on(), which is non-PRODUCT only 418 st->print ("Virtual space:"); 419 if (_storage.special()) st->print(" (pinned in memory)"); 420 st->cr(); 421 st->print_cr(" - committed: " SIZE_FORMAT, _storage.committed_size()); 422 st->print_cr(" - reserved: " SIZE_FORMAT, _storage.reserved_size()); 423 st->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_storage.low()), p2i(_storage.high())); 424 st->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_storage.low_boundary()), p2i(_storage.high_boundary())); 425 426 if (Verbose) { 427 print_heap_regions(st); 428 } 429 } 430 431 class InitGCLABClosure : public ThreadClosure { 432 public: 433 void do_thread(Thread* thread) { 434 thread->gclab().initialize(true); 435 } 436 }; 437 438 void ShenandoahHeap::post_initialize() { 439 if (UseTLAB) { 440 // This is a very tricky point in VM lifetime. We cannot easily call Threads::threads_do 441 // here, because some system threads (VMThread, WatcherThread, etc) are not yet available. 442 // Their initialization should be handled separately. Is we miss some threads here, 443 // then any other TLAB-related activity would fail with asserts. 444 445 InitGCLABClosure init_gclabs; 446 { 447 MutexLocker ml(Threads_lock); 448 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { 449 init_gclabs.do_thread(thread); 450 } 451 } 452 gc_threads_do(&init_gclabs); 453 454 // gclab can not be initialized early during VM startup, as it can not determinate its max_size. 455 // Now, we will let WorkGang to initialize gclab when new worker is created. 456 _workers->set_initialize_gclab(); 457 } 458 459 _scm->initialize(_max_workers); 460 461 ref_processing_init(); 462 } 463 464 class CalculateUsedRegionClosure : public ShenandoahHeapRegionClosure { 465 size_t sum; 466 public: 467 468 CalculateUsedRegionClosure() { 469 sum = 0; 470 } 471 472 bool doHeapRegion(ShenandoahHeapRegion* r) { 473 sum = sum + r->used(); 474 return false; 475 } 476 477 size_t getResult() { return sum;} 478 }; 479 480 size_t ShenandoahHeap::calculateUsed() { 481 CalculateUsedRegionClosure cl; 482 heap_region_iterate(&cl); 483 return cl.getResult(); 484 } 485 486 void ShenandoahHeap::verify_heap_size_consistency() { 487 488 assert(calculateUsed() == used(), 489 "heap used size must be consistent heap-used: "SIZE_FORMAT" regions-used: "SIZE_FORMAT, used(), calculateUsed()); 490 } 491 492 size_t ShenandoahHeap::used() const { 493 OrderAccess::acquire(); 494 return _used; 495 } 496 497 void ShenandoahHeap::increase_used(size_t bytes) { 498 assert_heaplock_or_safepoint(); 499 _used += bytes; 500 } 501 502 void ShenandoahHeap::set_used(size_t bytes) { 503 assert_heaplock_or_safepoint(); 504 _used = bytes; 505 } 506 507 void ShenandoahHeap::decrease_used(size_t bytes) { 508 assert_heaplock_or_safepoint(); 509 assert(_used >= bytes, "never decrease heap size by more than we've left"); 510 _used -= bytes; 511 } 512 513 size_t ShenandoahHeap::capacity() const { 514 return _num_regions * ShenandoahHeapRegion::RegionSizeBytes; 515 } 516 517 bool ShenandoahHeap::is_maximal_no_gc() const { 518 Unimplemented(); 519 return true; 520 } 521 522 size_t ShenandoahHeap::max_capacity() const { 523 return _max_regions * ShenandoahHeapRegion::RegionSizeBytes; 524 } 525 526 size_t ShenandoahHeap::min_capacity() const { 527 return _initialSize; 528 } 529 530 VirtualSpace* ShenandoahHeap::storage() const { 531 return (VirtualSpace*) &_storage; 532 } 533 534 bool ShenandoahHeap::is_in(const void* p) const { 535 HeapWord* first_region_bottom = _first_region->bottom(); 536 HeapWord* last_region_end = first_region_bottom + (ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize) * _num_regions; 537 return p >= _first_region_bottom && p < last_region_end; 538 } 539 540 bool ShenandoahHeap::is_scavengable(const void* p) { 541 return true; 542 } 543 544 HeapWord* ShenandoahHeap::allocate_from_gclab_slow(Thread* thread, size_t size) { 545 // Retain tlab and allocate object in shared space if 546 // the amount free in the tlab is too large to discard. 547 if (thread->gclab().free() > thread->gclab().refill_waste_limit()) { 548 thread->gclab().record_slow_allocation(size); 549 return NULL; 550 } 551 552 // Discard gclab and allocate a new one. 553 // To minimize fragmentation, the last GCLAB may be smaller than the rest. 554 size_t new_gclab_size = thread->gclab().compute_size(size); 555 556 thread->gclab().clear_before_allocation(); 557 558 if (new_gclab_size == 0) { 559 return NULL; 560 } 561 562 // Allocate a new GCLAB... 563 HeapWord* obj = allocate_new_gclab(new_gclab_size); 564 if (obj == NULL) { 565 return NULL; 566 } 567 568 if (ZeroTLAB) { 569 // ..and clear it. 570 Copy::zero_to_words(obj, new_gclab_size); 571 } else { 572 // ...and zap just allocated object. 573 #ifdef ASSERT 574 // Skip mangling the space corresponding to the object header to 575 // ensure that the returned space is not considered parsable by 576 // any concurrent GC thread. 577 size_t hdr_size = oopDesc::header_size(); 578 Copy::fill_to_words(obj + hdr_size, new_gclab_size - hdr_size, badHeapWordVal); 579 #endif // ASSERT 580 } 581 thread->gclab().fill(obj, obj + size, new_gclab_size); 582 return obj; 583 } 584 585 HeapWord* ShenandoahHeap::allocate_new_tlab(size_t word_size) { 586 return allocate_new_tlab(word_size, false); 587 } 588 589 HeapWord* ShenandoahHeap::allocate_new_gclab(size_t word_size) { 590 return allocate_new_tlab(word_size, true); 591 } 592 593 HeapWord* ShenandoahHeap::allocate_new_tlab(size_t word_size, bool evacuating) { 594 HeapWord* result = allocate_memory(word_size, evacuating); 595 596 if (result != NULL) { 597 assert(! in_collection_set(result), "Never allocate in dirty region"); 598 _bytes_allocated_since_cm += word_size * HeapWordSize; 599 600 log_develop_trace(gc, tlab)("allocating new tlab of size "SIZE_FORMAT" at addr "PTR_FORMAT, word_size, p2i(result)); 601 602 } 603 return result; 604 } 605 606 ShenandoahHeap* ShenandoahHeap::heap() { 607 CollectedHeap* heap = Universe::heap(); 608 assert(heap != NULL, "Unitialized access to ShenandoahHeap::heap()"); 609 assert(heap->kind() == CollectedHeap::ShenandoahHeap, "not a shenandoah heap"); 610 return (ShenandoahHeap*) heap; 611 } 612 613 ShenandoahHeap* ShenandoahHeap::heap_no_check() { 614 CollectedHeap* heap = Universe::heap(); 615 return (ShenandoahHeap*) heap; 616 } 617 618 HeapWord* ShenandoahHeap::allocate_memory_work(size_t word_size) { 619 620 ShenandoahHeapLock heap_lock(this); 621 622 HeapWord* result = allocate_memory_under_lock(word_size); 623 int grow_by = (word_size * HeapWordSize + ShenandoahHeapRegion::RegionSizeBytes - 1) / ShenandoahHeapRegion::RegionSizeBytes; 624 625 while (result == NULL && _num_regions + grow_by <= _max_regions) { 626 grow_heap_by(grow_by); 627 result = allocate_memory_under_lock(word_size); 628 } 629 630 return result; 631 } 632 633 HeapWord* ShenandoahHeap::allocate_memory(size_t word_size, bool evacuating) { 634 HeapWord* result = NULL; 635 result = allocate_memory_work(word_size); 636 637 if (!evacuating) { 638 // Allocation failed, try full-GC, then retry allocation. 639 // 640 // It might happen that one of the threads requesting allocation would unblock 641 // way later after full-GC happened, only to fail the second allocation, because 642 // other threads have already depleted the free storage. In this case, a better 643 // strategy would be to try full-GC again. 644 // 645 // Lacking the way to detect progress from "collect" call, we are left with blindly 646 // retrying for some bounded number of times. 647 // TODO: Poll if Full GC made enough progress to warrant retry. 648 int tries = 0; 649 while ((result == NULL) && (tries++ < ShenandoahFullGCTries)) { 650 log_debug(gc)("[" PTR_FORMAT " Failed to allocate " SIZE_FORMAT " bytes, doing full GC, try %d", 651 p2i(Thread::current()), word_size * HeapWordSize, tries); 652 collect(GCCause::_allocation_failure); 653 result = allocate_memory_work(word_size); 654 } 655 } 656 657 // Only update monitoring counters when not calling from a write-barrier. 658 // Otherwise we might attempt to grab the Service_lock, which we must 659 // not do when coming from a write-barrier (because the thread might 660 // already hold the Compile_lock). 661 if (! evacuating) { 662 monitoring_support()->update_counters(); 663 } 664 665 log_develop_trace(gc, alloc)("allocate memory chunk of size "SIZE_FORMAT" at addr "PTR_FORMAT " by thread %d ", 666 word_size, p2i(result), Thread::current()->osthread()->thread_id()); 667 668 return result; 669 } 670 671 bool ShenandoahHeap::call_from_write_barrier(bool evacuating) { 672 return evacuating && Thread::current()->is_Java_thread(); 673 } 674 675 HeapWord* ShenandoahHeap::allocate_memory_under_lock(size_t word_size) { 676 assert_heaplock_owned_by_current_thread(); 677 678 if (word_size * HeapWordSize > ShenandoahHeapRegion::RegionSizeBytes) { 679 return allocate_large_memory(word_size); 680 } 681 682 // Not enough memory in free region set. 683 // Coming out of full GC, it is possible that there is not 684 // free region available, so current_index may not be valid. 685 if (word_size * HeapWordSize > _free_regions->capacity()) return NULL; 686 687 ShenandoahHeapRegion* my_current_region = _free_regions->current_no_humongous(); 688 689 if (my_current_region == NULL) { 690 return NULL; // No more room to make a new region. OOM. 691 } 692 assert(my_current_region != NULL, "should have a region at this point"); 693 694 #ifdef ASSERT 695 if (in_collection_set(my_current_region)) { 696 print_heap_regions(); 697 } 698 #endif 699 assert(! in_collection_set(my_current_region), "never get targetted regions in free-lists"); 700 assert(! my_current_region->is_humongous(), "never attempt to allocate from humongous object regions"); 701 702 HeapWord* result = my_current_region->allocate(word_size); 703 704 while (result == NULL) { 705 // 2nd attempt. Try next region. 706 _free_regions->increase_used(my_current_region->free()); 707 ShenandoahHeapRegion* next_region = _free_regions->next_no_humongous(); 708 assert(next_region != my_current_region, "must not get current again"); 709 my_current_region = next_region; 710 711 if (my_current_region == NULL) { 712 return NULL; // No more room to make a new region. OOM. 713 } 714 assert(my_current_region != NULL, "should have a region at this point"); 715 assert(! in_collection_set(my_current_region), "never get targetted regions in free-lists"); 716 assert(! my_current_region->is_humongous(), "never attempt to allocate from humongous object regions"); 717 result = my_current_region->allocate(word_size); 718 } 719 720 my_current_region->increase_live_data_words(word_size); 721 increase_used(word_size * HeapWordSize); 722 _free_regions->increase_used(word_size * HeapWordSize); 723 return result; 724 } 725 726 HeapWord* ShenandoahHeap::allocate_large_memory(size_t words) { 727 assert_heaplock_owned_by_current_thread(); 728 729 uint required_regions = ShenandoahHumongous::required_regions(words * HeapWordSize); 730 if (required_regions > _max_regions) return NULL; 731 732 ShenandoahHeapRegion* r = _free_regions->allocate_contiguous(required_regions); 733 734 HeapWord* result = NULL; 735 736 if (r != NULL) { 737 result = r->bottom(); 738 739 log_debug(gc, humongous)("allocating humongous object of size: "SIZE_FORMAT" KB at location "PTR_FORMAT" in start region "SIZE_FORMAT, 740 (words * HeapWordSize) / K, p2i(result), r->region_number()); 741 } else { 742 log_debug(gc, humongous)("allocating humongous object of size: "SIZE_FORMAT" KB at location "PTR_FORMAT" failed", 743 (words * HeapWordSize) / K, p2i(result)); 744 } 745 746 747 return result; 748 749 } 750 751 HeapWord* ShenandoahHeap::mem_allocate(size_t size, 752 bool* gc_overhead_limit_was_exceeded) { 753 754 #ifdef ASSERT 755 if (ShenandoahVerify && _numAllocs > 1000000) { 756 _numAllocs = 0; 757 } 758 _numAllocs++; 759 #endif 760 HeapWord* filler = allocate_memory(BrooksPointer::word_size() + size, false); 761 HeapWord* result = filler + BrooksPointer::word_size(); 762 if (filler != NULL) { 763 BrooksPointer::initialize(oop(result)); 764 _bytes_allocated_since_cm += size * HeapWordSize; 765 766 assert(! in_collection_set(result), "never allocate in targetted region"); 767 return result; 768 } else { 769 /* 770 tty->print_cr("Out of memory. Requested number of words: "SIZE_FORMAT" used heap: "INT64_FORMAT", bytes allocated since last CM: "INT64_FORMAT, 771 size, used(), _bytes_allocated_since_cm); 772 { 773 print_heap_regions(); 774 tty->print("Printing "SIZE_FORMAT" free regions:\n", _free_regions->count()); 775 _free_regions->print(); 776 } 777 */ 778 return NULL; 779 } 780 } 781 782 class ParallelEvacuateRegionObjectClosure : public ObjectClosure { 783 private: 784 ShenandoahHeap* _heap; 785 Thread* _thread; 786 public: 787 ParallelEvacuateRegionObjectClosure(ShenandoahHeap* heap) : 788 _heap(heap), _thread(Thread::current()) { 789 } 790 791 void do_object(oop p) { 792 793 log_develop_trace(gc, compaction)("Calling ParallelEvacuateRegionObjectClosure on "PTR_FORMAT" of size %d\n", p2i((HeapWord*) p), p->size()); 794 795 assert(_heap->is_marked_complete(p), "expect only marked objects"); 796 if (oopDesc::unsafe_equals(p, ShenandoahBarrierSet::resolve_oop_static_not_null(p))) { 797 _heap->evacuate_object(p, _thread); 798 } 799 } 800 }; 801 802 #ifdef ASSERT 803 class VerifyEvacuatedObjectClosure : public ObjectClosure { 804 805 public: 806 807 void do_object(oop p) { 808 if (ShenandoahHeap::heap()->is_marked_complete(p)) { 809 oop p_prime = oopDesc::bs()->read_barrier(p); 810 assert(! oopDesc::unsafe_equals(p, p_prime), "Should point to evacuated copy"); 811 if (p->klass() != p_prime->klass()) { 812 tty->print_cr("copy has different class than original:"); 813 p->klass()->print_on(tty); 814 p_prime->klass()->print_on(tty); 815 } 816 assert(p->klass() == p_prime->klass(), "Should have the same class p: "PTR_FORMAT", p_prime: "PTR_FORMAT, p2i(p), p2i(p_prime)); 817 // assert(p->mark() == p_prime->mark(), "Should have the same mark"); 818 assert(p->size() == p_prime->size(), "Should be the same size"); 819 assert(oopDesc::unsafe_equals(p_prime, oopDesc::bs()->read_barrier(p_prime)), "One forward once"); 820 } 821 } 822 }; 823 824 void ShenandoahHeap::verify_evacuated_region(ShenandoahHeapRegion* from_region) { 825 VerifyEvacuatedObjectClosure verify_evacuation; 826 marked_object_iterate(from_region, &verify_evacuation); 827 } 828 #endif 829 830 void ShenandoahHeap::parallel_evacuate_region(ShenandoahHeapRegion* from_region) { 831 832 assert(from_region->has_live(), "all-garbage regions are reclaimed earlier"); 833 834 ParallelEvacuateRegionObjectClosure evacuate_region(this); 835 836 marked_object_iterate(from_region, &evacuate_region); 837 838 #ifdef ASSERT 839 if (ShenandoahVerify && ! cancelled_concgc()) { 840 verify_evacuated_region(from_region); 841 } 842 #endif 843 } 844 845 class ParallelEvacuationTask : public AbstractGangTask { 846 private: 847 ShenandoahHeap* _sh; 848 ShenandoahCollectionSet* _cs; 849 850 public: 851 ParallelEvacuationTask(ShenandoahHeap* sh, 852 ShenandoahCollectionSet* cs) : 853 AbstractGangTask("Parallel Evacuation Task"), 854 _cs(cs), 855 _sh(sh) {} 856 857 void work(uint worker_id) { 858 859 ShenandoahHeapRegion* from_hr = _cs->claim_next(); 860 861 while (from_hr != NULL) { 862 log_develop_trace(gc, region)("Thread "INT32_FORMAT" claimed Heap Region "SIZE_FORMAT, 863 worker_id, 864 from_hr->region_number()); 865 866 assert(from_hr->has_live(), "all-garbage regions are reclaimed early"); 867 _sh->parallel_evacuate_region(from_hr); 868 869 if (_sh->cancelled_concgc()) { 870 log_develop_trace(gc, region)("Cancelled concgc while evacuating region " SIZE_FORMAT "\n", from_hr->region_number()); 871 break; 872 } 873 from_hr = _cs->claim_next(); 874 } 875 } 876 }; 877 878 class RecycleDirtyRegionsClosure: public ShenandoahHeapRegionClosure { 879 private: 880 ShenandoahHeap* _heap; 881 size_t _bytes_reclaimed; 882 public: 883 RecycleDirtyRegionsClosure() : _heap(ShenandoahHeap::heap()) {} 884 885 bool doHeapRegion(ShenandoahHeapRegion* r) { 886 887 assert (! _heap->cancelled_concgc(), "no recycling after cancelled marking"); 888 889 if (_heap->in_collection_set(r)) { 890 log_develop_trace(gc, region)("Recycling region " SIZE_FORMAT ":", r->region_number()); 891 _heap->decrease_used(r->used()); 892 _bytes_reclaimed += r->used(); 893 r->recycle(); 894 } 895 896 return false; 897 } 898 size_t bytes_reclaimed() { return _bytes_reclaimed;} 899 void clear_bytes_reclaimed() {_bytes_reclaimed = 0;} 900 }; 901 902 void ShenandoahHeap::recycle_dirty_regions() { 903 RecycleDirtyRegionsClosure cl; 904 cl.clear_bytes_reclaimed(); 905 906 heap_region_iterate(&cl); 907 908 _shenandoah_policy->record_bytes_reclaimed(cl.bytes_reclaimed()); 909 if (! cancelled_concgc()) { 910 clear_cset_fast_test(); 911 } 912 } 913 914 ShenandoahFreeSet* ShenandoahHeap::free_regions() { 915 return _free_regions; 916 } 917 918 void ShenandoahHeap::print_heap_regions(outputStream* st) const { 919 _ordered_regions->print(st); 920 } 921 922 class PrintAllRefsOopClosure: public ExtendedOopClosure { 923 private: 924 int _index; 925 const char* _prefix; 926 927 public: 928 PrintAllRefsOopClosure(const char* prefix) : _index(0), _prefix(prefix) {} 929 930 private: 931 template <class T> 932 inline void do_oop_work(T* p) { 933 oop o = oopDesc::load_decode_heap_oop(p); 934 if (o != NULL) { 935 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop()) { 936 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT")-> "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT")", 937 _prefix, _index, 938 p2i(p), p2i(o), 939 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(o)), 940 o->klass()->internal_name(), p2i(o->klass())); 941 } else { 942 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT" dirty -> "PTR_FORMAT" (not in heap, possibly corrupted or dirty)", 943 _prefix, _index, 944 p2i(p), p2i(o)); 945 } 946 } else { 947 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT") -> "PTR_FORMAT, _prefix, _index, p2i(p), p2i((HeapWord*) o)); 948 } 949 _index++; 950 } 951 952 public: 953 void do_oop(oop* p) { 954 do_oop_work(p); 955 } 956 957 void do_oop(narrowOop* p) { 958 do_oop_work(p); 959 } 960 961 }; 962 963 class PrintAllRefsObjectClosure : public ObjectClosure { 964 const char* _prefix; 965 966 public: 967 PrintAllRefsObjectClosure(const char* prefix) : _prefix(prefix) {} 968 969 void do_object(oop p) { 970 if (ShenandoahHeap::heap()->is_in(p)) { 971 tty->print_cr("%s object "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT") refers to:", 972 _prefix, p2i(p), 973 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(p)), 974 p->klass()->internal_name(), p2i(p->klass())); 975 PrintAllRefsOopClosure cl(_prefix); 976 p->oop_iterate(&cl); 977 } 978 } 979 }; 980 981 void ShenandoahHeap::print_all_refs(const char* prefix) { 982 tty->print_cr("printing all references in the heap"); 983 tty->print_cr("root references:"); 984 985 ensure_parsability(false); 986 987 PrintAllRefsOopClosure cl(prefix); 988 roots_iterate(&cl); 989 990 tty->print_cr("heap references:"); 991 PrintAllRefsObjectClosure cl2(prefix); 992 object_iterate(&cl2); 993 } 994 995 class VerifyAfterMarkingOopClosure: public ExtendedOopClosure { 996 private: 997 ShenandoahHeap* _heap; 998 999 public: 1000 VerifyAfterMarkingOopClosure() : 1001 _heap(ShenandoahHeap::heap()) { } 1002 1003 private: 1004 template <class T> 1005 inline void do_oop_work(T* p) { 1006 oop o = oopDesc::load_decode_heap_oop(p); 1007 if (o != NULL) { 1008 if (! _heap->is_marked_complete(o)) { 1009 _heap->print_heap_regions(); 1010 _heap->print_all_refs("post-mark"); 1011 tty->print_cr("oop not marked, although referrer is marked: "PTR_FORMAT": in_heap: %s, is_marked: %s", 1012 p2i((HeapWord*) o), BOOL_TO_STR(_heap->is_in(o)), BOOL_TO_STR(_heap->is_marked_complete(o))); 1013 _heap->print_heap_locations((HeapWord*) o, (HeapWord*) o + o->size()); 1014 1015 tty->print_cr("oop class: %s", o->klass()->internal_name()); 1016 if (_heap->is_in(p)) { 1017 oop referrer = oop(_heap->heap_region_containing(p)->block_start_const(p)); 1018 tty->print_cr("Referrer starts at addr "PTR_FORMAT, p2i((HeapWord*) referrer)); 1019 referrer->print(); 1020 _heap->print_heap_locations((HeapWord*) referrer, (HeapWord*) referrer + referrer->size()); 1021 } 1022 tty->print_cr("heap region containing object:"); 1023 _heap->heap_region_containing(o)->print(); 1024 tty->print_cr("heap region containing referrer:"); 1025 _heap->heap_region_containing(p)->print(); 1026 tty->print_cr("heap region containing forwardee:"); 1027 _heap->heap_region_containing(oopDesc::bs()->read_barrier(o))->print(); 1028 } 1029 assert(o->is_oop(), "oop must be an oop"); 1030 assert(Metaspace::contains(o->klass()), "klass pointer must go to metaspace"); 1031 if (! oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o))) { 1032 tty->print_cr("oops has forwardee: p: "PTR_FORMAT" (%s), o = "PTR_FORMAT" (%s), new-o: "PTR_FORMAT" (%s)", 1033 p2i(p), 1034 BOOL_TO_STR(_heap->in_collection_set(p)), 1035 p2i(o), 1036 BOOL_TO_STR(_heap->in_collection_set(o)), 1037 p2i((HeapWord*) oopDesc::bs()->read_barrier(o)), 1038 BOOL_TO_STR(_heap->in_collection_set(oopDesc::bs()->read_barrier(o)))); 1039 tty->print_cr("oop class: %s", o->klass()->internal_name()); 1040 } 1041 assert(oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o)), "oops must not be forwarded"); 1042 assert(! _heap->in_collection_set(o), "references must not point to dirty heap regions"); 1043 assert(_heap->is_marked_complete(o), "live oops must be marked current"); 1044 } 1045 } 1046 1047 public: 1048 void do_oop(oop* p) { 1049 do_oop_work(p); 1050 } 1051 1052 void do_oop(narrowOop* p) { 1053 do_oop_work(p); 1054 } 1055 1056 }; 1057 1058 void ShenandoahHeap::verify_heap_after_marking() { 1059 1060 verify_heap_size_consistency(); 1061 1062 log_trace(gc)("verifying heap after marking"); 1063 1064 VerifyAfterMarkingOopClosure cl; 1065 roots_iterate(&cl); 1066 ObjectToOopClosure objs(&cl); 1067 object_iterate(&objs); 1068 } 1069 1070 1071 void ShenandoahHeap::reclaim_humongous_region_at(ShenandoahHeapRegion* r) { 1072 assert(r->is_humongous_start(), "reclaim regions starting with the first one"); 1073 1074 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size()); 1075 size_t size = humongous_obj->size() + BrooksPointer::word_size(); 1076 uint required_regions = ShenandoahHumongous::required_regions(size * HeapWordSize); 1077 uint index = r->region_number(); 1078 1079 1080 assert(!r->has_live(), "liveness must be zero"); 1081 1082 for(size_t i = 0; i < required_regions; i++) { 1083 1084 ShenandoahHeapRegion* region = _ordered_regions->get(index++); 1085 1086 assert((region->is_humongous_start() || region->is_humongous_continuation()), 1087 "expect correct humongous start or continuation"); 1088 1089 if (log_is_enabled(Debug, gc, humongous)) { 1090 log_debug(gc, humongous)("reclaiming "UINT32_FORMAT" humongous regions for object of size: "SIZE_FORMAT" words", required_regions, size); 1091 ResourceMark rm; 1092 outputStream* out = Log(gc, humongous)::debug_stream(); 1093 region->print_on(out); 1094 } 1095 1096 region->recycle(); 1097 ShenandoahHeap::heap()->decrease_used(ShenandoahHeapRegion::RegionSizeBytes); 1098 } 1099 } 1100 1101 class ShenandoahReclaimHumongousRegionsClosure : public ShenandoahHeapRegionClosure { 1102 1103 bool doHeapRegion(ShenandoahHeapRegion* r) { 1104 ShenandoahHeap* heap = ShenandoahHeap::heap(); 1105 1106 if (r->is_humongous_start()) { 1107 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size()); 1108 if (! heap->is_marked_complete(humongous_obj)) { 1109 1110 heap->reclaim_humongous_region_at(r); 1111 } 1112 } 1113 return false; 1114 } 1115 }; 1116 1117 #ifdef ASSERT 1118 class CheckCollectionSetClosure: public ShenandoahHeapRegionClosure { 1119 bool doHeapRegion(ShenandoahHeapRegion* r) { 1120 assert(! ShenandoahHeap::heap()->in_collection_set(r), "Should have been cleared by now"); 1121 return false; 1122 } 1123 }; 1124 #endif 1125 1126 void ShenandoahHeap::prepare_for_concurrent_evacuation() { 1127 assert(_ordered_regions->get(0)->region_number() == 0, "FIXME CHF. FIXME CHF!"); 1128 1129 log_develop_trace(gc)("Thread %d started prepare_for_concurrent_evacuation", Thread::current()->osthread()->thread_id()); 1130 1131 if (!cancelled_concgc()) { 1132 1133 recycle_dirty_regions(); 1134 1135 ensure_parsability(true); 1136 1137 #ifdef ASSERT 1138 if (ShenandoahVerify) { 1139 verify_heap_after_marking(); 1140 } 1141 1142 if (UseShenandoahMatrix) { 1143 if (PrintShenandoahMatrix) { 1144 connection_matrix()->print_on(tty); 1145 } 1146 if (VerifyShenandoahMatrix) { 1147 verify_matrix(); 1148 } 1149 } 1150 #endif 1151 1152 // NOTE: This needs to be done during a stop the world pause, because 1153 // putting regions into the collection set concurrently with Java threads 1154 // will create a race. In particular, acmp could fail because when we 1155 // resolve the first operand, the containing region might not yet be in 1156 // the collection set, and thus return the original oop. When the 2nd 1157 // operand gets resolved, the region could be in the collection set 1158 // and the oop gets evacuated. If both operands have originally been 1159 // the same, we get false negatives. 1160 1161 { 1162 ShenandoahHeapLock lock(this); 1163 _collection_set->clear(); 1164 _free_regions->clear(); 1165 1166 ShenandoahReclaimHumongousRegionsClosure reclaim; 1167 heap_region_iterate(&reclaim); 1168 1169 #ifdef ASSERT 1170 CheckCollectionSetClosure ccsc; 1171 _ordered_regions->heap_region_iterate(&ccsc); 1172 #endif 1173 1174 _shenandoah_policy->choose_collection_set(_collection_set); 1175 1176 _shenandoah_policy->choose_free_set(_free_regions); 1177 } 1178 1179 _bytes_allocated_since_cm = 0; 1180 1181 Universe::update_heap_info_at_gc(); 1182 } 1183 } 1184 1185 1186 class RetireTLABClosure : public ThreadClosure { 1187 private: 1188 bool _retire; 1189 1190 public: 1191 RetireTLABClosure(bool retire) : _retire(retire) { 1192 } 1193 1194 void do_thread(Thread* thread) { 1195 thread->gclab().make_parsable(_retire); 1196 } 1197 }; 1198 1199 void ShenandoahHeap::ensure_parsability(bool retire_tlabs) { 1200 if (UseTLAB) { 1201 CollectedHeap::ensure_parsability(retire_tlabs); 1202 RetireTLABClosure cl(retire_tlabs); 1203 Threads::threads_do(&cl); 1204 } 1205 } 1206 1207 class ShenandoahEvacuateUpdateRootsClosure: public ExtendedOopClosure { 1208 private: 1209 ShenandoahHeap* _heap; 1210 Thread* _thread; 1211 public: 1212 ShenandoahEvacuateUpdateRootsClosure() : 1213 _heap(ShenandoahHeap::heap()), _thread(Thread::current()) { 1214 } 1215 1216 private: 1217 template <class T> 1218 void do_oop_work(T* p) { 1219 assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress"); 1220 1221 T o = oopDesc::load_heap_oop(p); 1222 if (! oopDesc::is_null(o)) { 1223 oop obj = oopDesc::decode_heap_oop_not_null(o); 1224 if (_heap->in_collection_set(obj)) { 1225 assert(_heap->is_marked_complete(obj), "only evacuate marked objects %d %d", 1226 _heap->is_marked_complete(obj), _heap->is_marked_complete(ShenandoahBarrierSet::resolve_oop_static_not_null(obj))); 1227 oop resolved = ShenandoahBarrierSet::resolve_oop_static_not_null(obj); 1228 if (oopDesc::unsafe_equals(resolved, obj)) { 1229 resolved = _heap->evacuate_object(obj, _thread); 1230 } 1231 oopDesc::encode_store_heap_oop(p, resolved); 1232 } 1233 } 1234 #ifdef ASSERT 1235 else { 1236 // tty->print_cr("not updating root at: "PTR_FORMAT" with object: "PTR_FORMAT", is_in_heap: %s, is_in_cset: %s, is_marked: %s", 1237 // p2i(p), 1238 // p2i((HeapWord*) obj), 1239 // BOOL_TO_STR(_heap->is_in(obj)), 1240 // BOOL_TO_STR(_heap->in_cset_fast_test(obj)), 1241 // BOOL_TO_STR(_heap->is_marked_complete(obj))); 1242 } 1243 #endif 1244 } 1245 1246 public: 1247 void do_oop(oop* p) { 1248 do_oop_work(p); 1249 } 1250 void do_oop(narrowOop* p) { 1251 do_oop_work(p); 1252 } 1253 }; 1254 1255 class ShenandoahEvacuateUpdateRootsTask : public AbstractGangTask { 1256 ShenandoahRootEvacuator* _rp; 1257 public: 1258 1259 ShenandoahEvacuateUpdateRootsTask(ShenandoahRootEvacuator* rp) : 1260 AbstractGangTask("Shenandoah evacuate and update roots"), 1261 _rp(rp) 1262 { 1263 // Nothing else to do. 1264 } 1265 1266 void work(uint worker_id) { 1267 ShenandoahEvacuateUpdateRootsClosure cl; 1268 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations); 1269 1270 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id); 1271 } 1272 }; 1273 1274 class ShenandoahFixRootsTask : public AbstractGangTask { 1275 ShenandoahRootEvacuator* _rp; 1276 public: 1277 1278 ShenandoahFixRootsTask(ShenandoahRootEvacuator* rp) : 1279 AbstractGangTask("Shenandoah update roots"), 1280 _rp(rp) 1281 { 1282 // Nothing else to do. 1283 } 1284 1285 void work(uint worker_id) { 1286 SCMUpdateRefsClosure cl; 1287 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations); 1288 1289 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id); 1290 } 1291 }; 1292 void ShenandoahHeap::evacuate_and_update_roots() { 1293 1294 COMPILER2_PRESENT(DerivedPointerTable::clear()); 1295 1296 #ifdef ASSERT 1297 if (ShenandoahVerifyReadsToFromSpace) { 1298 set_from_region_protection(false); 1299 } 1300 #endif 1301 1302 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped"); 1303 ClassLoaderDataGraph::clear_claimed_marks(); 1304 1305 { 1306 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots); 1307 ShenandoahEvacuateUpdateRootsTask roots_task(&rp); 1308 workers()->run_task(&roots_task); 1309 } 1310 1311 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); 1312 1313 if (cancelled_concgc()) { 1314 // If initial evacuation has been cancelled, we need to update all references 1315 // after all workers have finished. Otherwise we might run into the following problem: 1316 // GC thread 1 cannot allocate anymore, thus evacuation fails, leaves from-space ptr of object X. 1317 // GC thread 2 evacuates the same object X to to-space 1318 // which leaves a truly dangling from-space reference in the first root oop*. This must not happen. 1319 // clear() and update_pointers() must always be called in pairs, 1320 // cannot nest with above clear()/update_pointers(). 1321 COMPILER2_PRESENT(DerivedPointerTable::clear()); 1322 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots); 1323 ShenandoahFixRootsTask update_roots_task(&rp); 1324 workers()->run_task(&update_roots_task); 1325 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); 1326 } 1327 1328 #ifdef ASSERT 1329 if (ShenandoahVerifyReadsToFromSpace) { 1330 set_from_region_protection(true); 1331 } 1332 #endif 1333 1334 #ifdef ASSERT 1335 { 1336 AssertToSpaceClosure cl; 1337 CodeBlobToOopClosure code_cl(&cl, !CodeBlobToOopClosure::FixRelocations); 1338 ShenandoahRootEvacuator rp(this, 1); 1339 rp.process_evacuate_roots(&cl, &code_cl, 0); 1340 } 1341 #endif 1342 } 1343 1344 1345 void ShenandoahHeap::do_evacuation() { 1346 1347 parallel_evacuate(); 1348 1349 if (ShenandoahVerify && ! cancelled_concgc()) { 1350 VM_ShenandoahVerifyHeapAfterEvacuation verify_after_evacuation; 1351 if (Thread::current()->is_VM_thread()) { 1352 verify_after_evacuation.doit(); 1353 } else { 1354 VMThread::execute(&verify_after_evacuation); 1355 } 1356 } 1357 1358 } 1359 1360 void ShenandoahHeap::parallel_evacuate() { 1361 log_develop_trace(gc)("starting parallel_evacuate"); 1362 1363 _shenandoah_policy->record_phase_start(ShenandoahCollectorPolicy::conc_evac); 1364 1365 if (log_is_enabled(Trace, gc, region)) { 1366 ResourceMark rm; 1367 outputStream *out = Log(gc, region)::trace_stream(); 1368 out->print("Printing all available regions"); 1369 print_heap_regions(out); 1370 } 1371 1372 if (log_is_enabled(Trace, gc, cset)) { 1373 ResourceMark rm; 1374 outputStream *out = Log(gc, cset)::trace_stream(); 1375 out->print("Printing collection set which contains "SIZE_FORMAT" regions:\n", _collection_set->count()); 1376 _collection_set->print(out); 1377 1378 out->print("Printing free set which contains "SIZE_FORMAT" regions:\n", _free_regions->count()); 1379 _free_regions->print(out); 1380 } 1381 1382 ParallelEvacuationTask evacuationTask = ParallelEvacuationTask(this, _collection_set); 1383 1384 1385 workers()->run_task(&evacuationTask); 1386 1387 if (log_is_enabled(Trace, gc, cset)) { 1388 ResourceMark rm; 1389 outputStream *out = Log(gc, cset)::trace_stream(); 1390 out->print("Printing postgc collection set which contains "SIZE_FORMAT" regions:\n", 1391 _collection_set->count()); 1392 1393 _collection_set->print(out); 1394 1395 out->print("Printing postgc free regions which contain "SIZE_FORMAT" free regions:\n", 1396 _free_regions->count()); 1397 _free_regions->print(out); 1398 1399 } 1400 1401 if (log_is_enabled(Trace, gc, region)) { 1402 ResourceMark rm; 1403 outputStream *out = Log(gc, region)::trace_stream(); 1404 out->print_cr("all regions after evacuation:"); 1405 print_heap_regions(out); 1406 } 1407 1408 _shenandoah_policy->record_phase_end(ShenandoahCollectorPolicy::conc_evac); 1409 } 1410 1411 class VerifyEvacuationClosure: public ExtendedOopClosure { 1412 private: 1413 ShenandoahHeap* _heap; 1414 ShenandoahHeapRegion* _from_region; 1415 1416 public: 1417 VerifyEvacuationClosure(ShenandoahHeapRegion* from_region) : 1418 _heap(ShenandoahHeap::heap()), _from_region(from_region) { } 1419 private: 1420 template <class T> 1421 inline void do_oop_work(T* p) { 1422 oop heap_oop = oopDesc::load_decode_heap_oop(p); 1423 if (! oopDesc::is_null(heap_oop)) { 1424 guarantee(! _from_region->is_in(heap_oop), "no references to from-region allowed after evacuation: "PTR_FORMAT, p2i((HeapWord*) heap_oop)); 1425 } 1426 } 1427 1428 public: 1429 void do_oop(oop* p) { 1430 do_oop_work(p); 1431 } 1432 1433 void do_oop(narrowOop* p) { 1434 do_oop_work(p); 1435 } 1436 1437 }; 1438 1439 void ShenandoahHeap::roots_iterate(OopClosure* cl) { 1440 1441 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped"); 1442 1443 CodeBlobToOopClosure blobsCl(cl, false); 1444 CLDToOopClosure cldCl(cl); 1445 1446 ClassLoaderDataGraph::clear_claimed_marks(); 1447 1448 ShenandoahRootProcessor rp(this, 1); 1449 rp.process_all_roots(cl, NULL, &cldCl, &blobsCl, 0); 1450 } 1451 1452 void ShenandoahHeap::verify_evacuation(ShenandoahHeapRegion* from_region) { 1453 1454 VerifyEvacuationClosure rootsCl(from_region); 1455 roots_iterate(&rootsCl); 1456 1457 } 1458 1459 bool ShenandoahHeap::supports_tlab_allocation() const { 1460 return true; 1461 } 1462 1463 1464 size_t ShenandoahHeap::unsafe_max_tlab_alloc(Thread *thread) const { 1465 size_t idx = _free_regions->current_index(); 1466 ShenandoahHeapRegion* current = _free_regions->get(idx); 1467 if (current == NULL) { 1468 return 0; 1469 } else if (current->free() > MinTLABSize) { 1470 // Current region has enough space left, can use it. 1471 return current->free(); 1472 } else { 1473 // No more space in current region, we will take next free region 1474 // on the next TLAB allocation. 1475 return ShenandoahHeapRegion::RegionSizeBytes; 1476 } 1477 } 1478 1479 size_t ShenandoahHeap::max_tlab_size() const { 1480 return ShenandoahHeapRegion::RegionSizeBytes; 1481 } 1482 1483 class ResizeGCLABClosure : public ThreadClosure { 1484 public: 1485 void do_thread(Thread* thread) { 1486 thread->gclab().resize(); 1487 } 1488 }; 1489 1490 void ShenandoahHeap::resize_all_tlabs() { 1491 CollectedHeap::resize_all_tlabs(); 1492 1493 ResizeGCLABClosure cl; 1494 Threads::threads_do(&cl); 1495 } 1496 1497 class AccumulateStatisticsGCLABClosure : public ThreadClosure { 1498 public: 1499 void do_thread(Thread* thread) { 1500 thread->gclab().accumulate_statistics(); 1501 thread->gclab().initialize_statistics(); 1502 } 1503 }; 1504 1505 void ShenandoahHeap::accumulate_statistics_all_gclabs() { 1506 AccumulateStatisticsGCLABClosure cl; 1507 Threads::threads_do(&cl); 1508 } 1509 1510 bool ShenandoahHeap::can_elide_tlab_store_barriers() const { 1511 return true; 1512 } 1513 1514 oop ShenandoahHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) { 1515 // Overridden to do nothing. 1516 return new_obj; 1517 } 1518 1519 bool ShenandoahHeap::can_elide_initializing_store_barrier(oop new_obj) { 1520 return true; 1521 } 1522 1523 bool ShenandoahHeap::card_mark_must_follow_store() const { 1524 return false; 1525 } 1526 1527 void ShenandoahHeap::collect(GCCause::Cause cause) { 1528 assert(cause != GCCause::_gc_locker, "no JNI critical callback"); 1529 if (GCCause::is_user_requested_gc(cause)) { 1530 if (! DisableExplicitGC) { 1531 _concurrent_gc_thread->do_full_gc(cause); 1532 } 1533 } else if (cause == GCCause::_allocation_failure) { 1534 collector_policy()->set_should_clear_all_soft_refs(true); 1535 _concurrent_gc_thread->do_full_gc(cause); 1536 } 1537 } 1538 1539 void ShenandoahHeap::do_full_collection(bool clear_all_soft_refs) { 1540 //assert(false, "Shouldn't need to do full collections"); 1541 } 1542 1543 AdaptiveSizePolicy* ShenandoahHeap::size_policy() { 1544 Unimplemented(); 1545 return NULL; 1546 1547 } 1548 1549 CollectorPolicy* ShenandoahHeap::collector_policy() const { 1550 return _shenandoah_policy; 1551 } 1552 1553 1554 HeapWord* ShenandoahHeap::block_start(const void* addr) const { 1555 Space* sp = heap_region_containing(addr); 1556 if (sp != NULL) { 1557 return sp->block_start(addr); 1558 } 1559 return NULL; 1560 } 1561 1562 size_t ShenandoahHeap::block_size(const HeapWord* addr) const { 1563 Space* sp = heap_region_containing(addr); 1564 assert(sp != NULL, "block_size of address outside of heap"); 1565 return sp->block_size(addr); 1566 } 1567 1568 bool ShenandoahHeap::block_is_obj(const HeapWord* addr) const { 1569 Space* sp = heap_region_containing(addr); 1570 return sp->block_is_obj(addr); 1571 } 1572 1573 jlong ShenandoahHeap::millis_since_last_gc() { 1574 return 0; 1575 } 1576 1577 void ShenandoahHeap::prepare_for_verify() { 1578 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { 1579 ensure_parsability(false); 1580 } 1581 } 1582 1583 void ShenandoahHeap::print_gc_threads_on(outputStream* st) const { 1584 workers()->print_worker_threads_on(st); 1585 } 1586 1587 void ShenandoahHeap::gc_threads_do(ThreadClosure* tcl) const { 1588 workers()->threads_do(tcl); 1589 } 1590 1591 void ShenandoahHeap::print_tracing_info() const { 1592 if (log_is_enabled(Info, gc, stats)) { 1593 ResourceMark rm; 1594 outputStream* out = Log(gc, stats)::info_stream(); 1595 _shenandoah_policy->print_tracing_info(out); 1596 } 1597 } 1598 1599 class ShenandoahVerifyRootsClosure: public ExtendedOopClosure { 1600 private: 1601 ShenandoahHeap* _heap; 1602 VerifyOption _vo; 1603 bool _failures; 1604 public: 1605 // _vo == UsePrevMarking -> use "prev" marking information, 1606 // _vo == UseNextMarking -> use "next" marking information, 1607 // _vo == UseMarkWord -> use mark word from object header. 1608 ShenandoahVerifyRootsClosure(VerifyOption vo) : 1609 _heap(ShenandoahHeap::heap()), 1610 _vo(vo), 1611 _failures(false) { } 1612 1613 bool failures() { return _failures; } 1614 1615 private: 1616 template <class T> 1617 inline void do_oop_work(T* p) { 1618 oop obj = oopDesc::load_decode_heap_oop(p); 1619 if (! oopDesc::is_null(obj) && ! obj->is_oop()) { 1620 { // Just for debugging. 1621 tty->print_cr("Root location "PTR_FORMAT 1622 "verified "PTR_FORMAT, p2i(p), p2i((void*) obj)); 1623 // obj->print_on(tty); 1624 } 1625 } 1626 guarantee(obj->is_oop_or_null(), "is oop or null"); 1627 } 1628 1629 public: 1630 void do_oop(oop* p) { 1631 do_oop_work(p); 1632 } 1633 1634 void do_oop(narrowOop* p) { 1635 do_oop_work(p); 1636 } 1637 1638 }; 1639 1640 class ShenandoahVerifyHeapClosure: public ObjectClosure { 1641 private: 1642 ShenandoahVerifyRootsClosure _rootsCl; 1643 public: 1644 ShenandoahVerifyHeapClosure(ShenandoahVerifyRootsClosure rc) : 1645 _rootsCl(rc) {}; 1646 1647 void do_object(oop p) { 1648 _rootsCl.do_oop(&p); 1649 } 1650 }; 1651 1652 class ShenandoahVerifyKlassClosure: public KlassClosure { 1653 OopClosure *_oop_closure; 1654 public: 1655 ShenandoahVerifyKlassClosure(OopClosure* cl) : _oop_closure(cl) {} 1656 void do_klass(Klass* k) { 1657 k->oops_do(_oop_closure); 1658 } 1659 }; 1660 1661 void ShenandoahHeap::verify(VerifyOption vo) { 1662 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { 1663 1664 ShenandoahVerifyRootsClosure rootsCl(vo); 1665 1666 assert(Thread::current()->is_VM_thread(), 1667 "Expected to be executed serially by the VM thread at this point"); 1668 1669 roots_iterate(&rootsCl); 1670 1671 bool failures = rootsCl.failures(); 1672 log_trace(gc)("verify failures: %s", BOOL_TO_STR(failures)); 1673 1674 ShenandoahVerifyHeapClosure heapCl(rootsCl); 1675 1676 object_iterate(&heapCl); 1677 // TODO: Implement rest of it. 1678 } else { 1679 tty->print("(SKIPPING roots, heapRegions, remset) "); 1680 } 1681 } 1682 size_t ShenandoahHeap::tlab_capacity(Thread *thr) const { 1683 return _free_regions->capacity(); 1684 } 1685 1686 class ShenandoahIterateObjectClosureRegionClosure: public ShenandoahHeapRegionClosure { 1687 ObjectClosure* _cl; 1688 public: 1689 ShenandoahIterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {} 1690 bool doHeapRegion(ShenandoahHeapRegion* r) { 1691 ShenandoahHeap::heap()->marked_object_iterate(r, _cl); 1692 return false; 1693 } 1694 }; 1695 1696 void ShenandoahHeap::object_iterate(ObjectClosure* cl) { 1697 ShenandoahIterateObjectClosureRegionClosure blk(cl); 1698 heap_region_iterate(&blk, false, true); 1699 } 1700 1701 class ShenandoahSafeObjectIterateAdjustPtrsClosure : public MetadataAwareOopClosure { 1702 private: 1703 ShenandoahHeap* _heap; 1704 1705 public: 1706 ShenandoahSafeObjectIterateAdjustPtrsClosure() : _heap(ShenandoahHeap::heap()) {} 1707 1708 private: 1709 template <class T> 1710 inline void do_oop_work(T* p) { 1711 T o = oopDesc::load_heap_oop(p); 1712 if (!oopDesc::is_null(o)) { 1713 oop obj = oopDesc::decode_heap_oop_not_null(o); 1714 oopDesc::encode_store_heap_oop(p, BrooksPointer::forwardee(obj)); 1715 } 1716 } 1717 public: 1718 void do_oop(oop* p) { 1719 do_oop_work(p); 1720 } 1721 void do_oop(narrowOop* p) { 1722 do_oop_work(p); 1723 } 1724 }; 1725 1726 class ShenandoahSafeObjectIterateAndUpdate : public ObjectClosure { 1727 private: 1728 ObjectClosure* _cl; 1729 public: 1730 ShenandoahSafeObjectIterateAndUpdate(ObjectClosure *cl) : _cl(cl) {} 1731 1732 virtual void do_object(oop obj) { 1733 assert (oopDesc::unsafe_equals(obj, BrooksPointer::forwardee(obj)), 1734 "avoid double-counting: only non-forwarded objects here"); 1735 1736 // Fix up the ptrs. 1737 ShenandoahSafeObjectIterateAdjustPtrsClosure adjust_ptrs; 1738 obj->oop_iterate(&adjust_ptrs); 1739 1740 // Can reply the object now: 1741 _cl->do_object(obj); 1742 } 1743 }; 1744 1745 void ShenandoahHeap::safe_object_iterate(ObjectClosure* cl) { 1746 assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints"); 1747 1748 // Safe iteration does objects only with correct references. 1749 // This is why we skip dirty regions that have stale copies of objects, 1750 // and fix up the pointers in the returned objects. 1751 1752 ShenandoahSafeObjectIterateAndUpdate safe_cl(cl); 1753 ShenandoahIterateObjectClosureRegionClosure blk(&safe_cl); 1754 heap_region_iterate(&blk, 1755 /* skip_dirty_regions = */ true, 1756 /* skip_humongous_continuations = */ true); 1757 1758 _need_update_refs = false; // already updated the references 1759 } 1760 1761 // Apply blk->doHeapRegion() on all committed regions in address order, 1762 // terminating the iteration early if doHeapRegion() returns true. 1763 void ShenandoahHeap::heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions, bool skip_humongous_continuation) const { 1764 for (size_t i = 0; i < _num_regions; i++) { 1765 ShenandoahHeapRegion* current = _ordered_regions->get(i); 1766 if (skip_humongous_continuation && current->is_humongous_continuation()) { 1767 continue; 1768 } 1769 if (skip_dirty_regions && in_collection_set(current)) { 1770 continue; 1771 } 1772 if (blk->doHeapRegion(current)) { 1773 return; 1774 } 1775 } 1776 } 1777 1778 class ClearLivenessClosure : public ShenandoahHeapRegionClosure { 1779 ShenandoahHeap* sh; 1780 public: 1781 ClearLivenessClosure(ShenandoahHeap* heap) : sh(heap) { } 1782 1783 bool doHeapRegion(ShenandoahHeapRegion* r) { 1784 r->clear_live_data(); 1785 sh->set_next_top_at_mark_start(r->bottom(), r->top()); 1786 return false; 1787 } 1788 }; 1789 1790 void ShenandoahHeap::start_concurrent_marking() { 1791 1792 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::accumulate_stats); 1793 accumulate_statistics_all_tlabs(); 1794 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::accumulate_stats); 1795 1796 set_concurrent_mark_in_progress(true); 1797 // We need to reset all TLABs because we'd lose marks on all objects allocated in them. 1798 if (UseTLAB) { 1799 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::make_parsable); 1800 ensure_parsability(true); 1801 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::make_parsable); 1802 } 1803 1804 _shenandoah_policy->record_bytes_allocated(_bytes_allocated_since_cm); 1805 _used_start_gc = used(); 1806 1807 #ifdef ASSERT 1808 if (ShenandoahDumpHeapBeforeConcurrentMark) { 1809 ensure_parsability(false); 1810 print_all_refs("pre-mark"); 1811 } 1812 #endif 1813 1814 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::clear_liveness); 1815 ClearLivenessClosure clc(this); 1816 heap_region_iterate(&clc); 1817 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::clear_liveness); 1818 1819 if (UseShenandoahMatrix) { 1820 connection_matrix()->clear_all(); 1821 } 1822 // print_all_refs("pre -mark"); 1823 1824 // oopDesc::_debug = true; 1825 1826 // Make above changes visible to worker threads 1827 OrderAccess::fence(); 1828 1829 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::scan_roots); 1830 concurrentMark()->init_mark_roots(); 1831 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::scan_roots); 1832 1833 // print_all_refs("pre-mark2"); 1834 } 1835 1836 class VerifyAfterEvacuationClosure : public ExtendedOopClosure { 1837 1838 ShenandoahHeap* _sh; 1839 1840 public: 1841 VerifyAfterEvacuationClosure() : _sh ( ShenandoahHeap::heap() ) {} 1842 1843 template<class T> void do_oop_nv(T* p) { 1844 T heap_oop = oopDesc::load_heap_oop(p); 1845 if (!oopDesc::is_null(heap_oop)) { 1846 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 1847 guarantee(_sh->in_collection_set(obj) == (! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))), 1848 "forwarded objects can only exist in dirty (from-space) regions is_dirty: %s, is_forwarded: %s obj-klass: %s, marked: %s", 1849 BOOL_TO_STR(_sh->in_collection_set(obj)), 1850 BOOL_TO_STR(! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))), 1851 obj->klass()->external_name(), 1852 BOOL_TO_STR(_sh->is_marked_complete(obj)) 1853 ); 1854 obj = oopDesc::bs()->read_barrier(obj); 1855 guarantee(! _sh->in_collection_set(obj), "forwarded oops must not point to dirty regions"); 1856 guarantee(obj->is_oop(), "is_oop"); 1857 guarantee(Metaspace::contains(obj->klass()), "klass pointer must go to metaspace"); 1858 } 1859 } 1860 1861 void do_oop(oop* p) { do_oop_nv(p); } 1862 void do_oop(narrowOop* p) { do_oop_nv(p); } 1863 1864 }; 1865 1866 void ShenandoahHeap::verify_heap_after_evacuation() { 1867 1868 verify_heap_size_consistency(); 1869 1870 ensure_parsability(false); 1871 1872 VerifyAfterEvacuationClosure cl; 1873 roots_iterate(&cl); 1874 1875 ObjectToOopClosure objs(&cl); 1876 object_iterate(&objs); 1877 1878 } 1879 1880 class VerifyRegionsAfterUpdateRefsClosure : public ShenandoahHeapRegionClosure { 1881 public: 1882 bool doHeapRegion(ShenandoahHeapRegion* r) { 1883 assert(! ShenandoahHeap::heap()->in_collection_set(r), "no region must be in collection set"); 1884 return false; 1885 } 1886 }; 1887 1888 void ShenandoahHeap::swap_mark_bitmaps() { 1889 // Swap bitmaps. 1890 CMBitMap* tmp1 = _complete_mark_bit_map; 1891 _complete_mark_bit_map = _next_mark_bit_map; 1892 _next_mark_bit_map = tmp1; 1893 1894 // Swap top-at-mark-start pointers 1895 HeapWord** tmp2 = _complete_top_at_mark_starts; 1896 _complete_top_at_mark_starts = _next_top_at_mark_starts; 1897 _next_top_at_mark_starts = tmp2; 1898 1899 HeapWord** tmp3 = _complete_top_at_mark_starts_base; 1900 _complete_top_at_mark_starts_base = _next_top_at_mark_starts_base; 1901 _next_top_at_mark_starts_base = tmp3; 1902 } 1903 1904 class ShenandoahVerifyMatrixOopClosure : public ExtendedOopClosure { 1905 private: 1906 oop _obj; 1907 1908 template <class T> 1909 inline void do_oop_nv(T* p) { 1910 T o = oopDesc::load_heap_oop(p); 1911 if (! oopDesc::is_null(o)) { 1912 oop obj = oopDesc::decode_heap_oop_not_null(o); 1913 ShenandoahHeap* heap = ShenandoahHeap::heap(); 1914 guarantee(heap->is_marked_complete(obj), "must be marked"); 1915 1916 uint from_idx = heap->heap_region_index_containing(p); 1917 uint to_idx = heap->heap_region_index_containing(obj); 1918 if (!heap->connection_matrix()->is_connected(from_idx, to_idx)) { 1919 tty->print_cr("from-obj: "); 1920 _obj->print_on(tty); 1921 tty->print_cr("to-obj:"); 1922 obj->print_on(tty); 1923 tty->print_cr("from-obj allocated after mark: %s", BOOL_TO_STR(heap->allocated_after_complete_mark_start((HeapWord*) _obj))); 1924 tty->print_cr("to-obj allocated after mark: %s", BOOL_TO_STR(heap->allocated_after_complete_mark_start((HeapWord*) obj))); 1925 tty->print_cr("from-obj marked: %s", BOOL_TO_STR(heap->is_marked_complete(_obj))); 1926 tty->print_cr("to-obj marked: %s", BOOL_TO_STR(heap->is_marked_complete(obj))); 1927 tty->print_cr("from-idx: %u, to-idx: %u", from_idx, to_idx); 1928 1929 oop fwd_from = BrooksPointer::forwardee(_obj); 1930 oop fwd_to = BrooksPointer::forwardee(obj); 1931 tty->print_cr("from-obj forwardee: " PTR_FORMAT, p2i(fwd_from)); 1932 tty->print_cr("to-obj forwardee: " PTR_FORMAT, p2i(fwd_to)); 1933 tty->print_cr("forward(from-obj) marked: %s", BOOL_TO_STR(heap->is_marked_complete(fwd_from))); 1934 tty->print_cr("forward(to-obj) marked: %s", BOOL_TO_STR(heap->is_marked_complete(fwd_to))); 1935 uint fwd_from_idx = heap->heap_region_index_containing(fwd_from); 1936 uint fwd_to_idx = heap->heap_region_index_containing(fwd_to); 1937 tty->print_cr("forward(from-idx): %u, forward(to-idx): %u", fwd_from_idx, fwd_to_idx); 1938 tty->print_cr("forward(from) connected with forward(to)? %s", BOOL_TO_STR(heap->connection_matrix()->is_connected(fwd_from_idx, fwd_to_idx))); 1939 tty->print_cr("sizeof(bool): %lu", sizeof(bool)); 1940 } 1941 guarantee(oopDesc::unsafe_equals(ShenandoahBarrierSet::resolve_oop_static_not_null(obj), obj), "polizeilich verboten"); 1942 guarantee(heap->connection_matrix()->is_connected(from_idx, to_idx), "must be connected"); 1943 } 1944 } 1945 1946 public: 1947 ShenandoahVerifyMatrixOopClosure(oop obj) : _obj(obj) {} 1948 1949 void do_oop(oop* o) { 1950 do_oop_nv(o); 1951 } 1952 1953 void do_oop(narrowOop* o) { 1954 do_oop_nv(o); 1955 } 1956 }; 1957 1958 class ShenandoahVerifyMatrixObjectClosure : public ObjectClosure { 1959 public: 1960 void do_object(oop obj) { 1961 guarantee(ShenandoahHeap::heap()->is_marked_complete(obj), "must be marked"); 1962 ShenandoahVerifyMatrixOopClosure cl(obj); 1963 obj->oop_iterate(&cl); 1964 } 1965 1966 }; 1967 1968 class ShenandoahVerifyMatrixRegionClosure : public ShenandoahHeapRegionClosure { 1969 bool doHeapRegion(ShenandoahHeapRegion* r) { 1970 ShenandoahVerifyMatrixObjectClosure cl; 1971 ShenandoahHeap::heap()->marked_object_iterate(r, &cl); 1972 return false; 1973 } 1974 }; 1975 1976 void ShenandoahHeap::verify_matrix() { 1977 OrderAccess::fence(); 1978 ensure_parsability(false); 1979 ShenandoahVerifyMatrixRegionClosure cl; 1980 heap_region_iterate(&cl, true, true); 1981 } 1982 1983 void ShenandoahHeap::stop_concurrent_marking() { 1984 assert(concurrent_mark_in_progress(), "How else could we get here?"); 1985 if (! cancelled_concgc()) { 1986 // If we needed to update refs, and concurrent marking has been cancelled, 1987 // we need to finish updating references. 1988 set_need_update_refs(false); 1989 swap_mark_bitmaps(); 1990 } 1991 set_concurrent_mark_in_progress(false); 1992 1993 if (log_is_enabled(Trace, gc, region)) { 1994 ResourceMark rm; 1995 outputStream* out = Log(gc, region)::trace_stream(); 1996 print_heap_regions(out); 1997 } 1998 1999 } 2000 2001 void ShenandoahHeap::set_concurrent_mark_in_progress(bool in_progress) { 2002 _concurrent_mark_in_progress = in_progress ? 1 : 0; 2003 JavaThread::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress); 2004 } 2005 2006 void ShenandoahHeap::set_evacuation_in_progress_concurrently(bool in_progress) { 2007 // Note: it is important to first release the _evacuation_in_progress flag here, 2008 // so that Java threads can get out of oom_during_evacuation() and reach a safepoint, 2009 // in case a VM task is pending. 2010 set_evacuation_in_progress(in_progress); 2011 MutexLocker mu(Threads_lock); 2012 JavaThread::set_evacuation_in_progress_all_threads(in_progress); 2013 } 2014 2015 void ShenandoahHeap::set_evacuation_in_progress_at_safepoint(bool in_progress) { 2016 assert(SafepointSynchronize::is_at_safepoint(), "Only call this at safepoint"); 2017 set_evacuation_in_progress(in_progress); 2018 JavaThread::set_evacuation_in_progress_all_threads(in_progress); 2019 } 2020 2021 void ShenandoahHeap::set_evacuation_in_progress(bool in_progress) { 2022 _evacuation_in_progress = in_progress ? 1 : 0; 2023 OrderAccess::fence(); 2024 } 2025 2026 void ShenandoahHeap::verify_copy(oop p,oop c){ 2027 assert(! oopDesc::unsafe_equals(p, oopDesc::bs()->read_barrier(p)), "forwarded correctly"); 2028 assert(oopDesc::unsafe_equals(oopDesc::bs()->read_barrier(p), c), "verify pointer is correct"); 2029 if (p->klass() != c->klass()) { 2030 print_heap_regions(); 2031 } 2032 assert(p->klass() == c->klass(), "verify class p-size: "INT32_FORMAT" c-size: "INT32_FORMAT, p->size(), c->size()); 2033 assert(p->size() == c->size(), "verify size"); 2034 // Object may have been locked between copy and verification 2035 // assert(p->mark() == c->mark(), "verify mark"); 2036 assert(oopDesc::unsafe_equals(c, oopDesc::bs()->read_barrier(c)), "verify only forwarded once"); 2037 } 2038 2039 void ShenandoahHeap::oom_during_evacuation() { 2040 log_develop_trace(gc)("Out of memory during evacuation, cancel evacuation, schedule full GC by thread %d", 2041 Thread::current()->osthread()->thread_id()); 2042 2043 // We ran out of memory during evacuation. Cancel evacuation, and schedule a full-GC. 2044 collector_policy()->set_should_clear_all_soft_refs(true); 2045 concurrent_thread()->try_set_full_gc(); 2046 cancel_concgc(_oom_evacuation); 2047 2048 if ((! Thread::current()->is_GC_task_thread()) && (! Thread::current()->is_ConcurrentGC_thread())) { 2049 assert(! Threads_lock->owned_by_self() 2050 || SafepointSynchronize::is_at_safepoint(), "must not hold Threads_lock here"); 2051 log_warning(gc)("OOM during evacuation. Let Java thread wait until evacuation finishes."); 2052 while (_evacuation_in_progress) { // wait. 2053 Thread::current()->_ParkEvent->park(1); 2054 } 2055 } 2056 2057 } 2058 2059 HeapWord* ShenandoahHeap::tlab_post_allocation_setup(HeapWord* obj) { 2060 // Initialize Brooks pointer for the next object 2061 HeapWord* result = obj + BrooksPointer::word_size(); 2062 BrooksPointer::initialize(oop(result)); 2063 return result; 2064 } 2065 2066 uint ShenandoahHeap::oop_extra_words() { 2067 return BrooksPointer::word_size(); 2068 } 2069 2070 void ShenandoahHeap::grow_heap_by(size_t num_regions) { 2071 size_t base = _num_regions; 2072 ensure_new_regions(num_regions); 2073 for (size_t i = 0; i < num_regions; i++) { 2074 size_t new_region_index = i + base; 2075 HeapWord* start = _first_region_bottom + (ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize) * new_region_index; 2076 ShenandoahHeapRegion* new_region = new ShenandoahHeapRegion(this, start, ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize, new_region_index); 2077 2078 if (log_is_enabled(Trace, gc, region)) { 2079 ResourceMark rm; 2080 outputStream* out = Log(gc, region)::trace_stream(); 2081 out->print_cr("allocating new region at index: "SIZE_FORMAT, new_region_index); 2082 new_region->print_on(out); 2083 } 2084 2085 assert(_ordered_regions->active_regions() == new_region->region_number(), "must match"); 2086 _ordered_regions->add_region(new_region); 2087 _in_cset_fast_test_base[new_region_index] = false; // Not in cset 2088 _next_top_at_mark_starts_base[new_region_index] = new_region->bottom(); 2089 _complete_top_at_mark_starts_base[new_region_index] = new_region->bottom(); 2090 2091 _free_regions->add_region(new_region); 2092 } 2093 } 2094 2095 void ShenandoahHeap::ensure_new_regions(size_t new_regions) { 2096 2097 size_t num_regions = _num_regions; 2098 size_t new_num_regions = num_regions + new_regions; 2099 assert(new_num_regions <= _max_regions, "we checked this earlier"); 2100 2101 size_t expand_size = new_regions * ShenandoahHeapRegion::RegionSizeBytes; 2102 log_trace(gc, region)("expanding storage by "SIZE_FORMAT_HEX" bytes, for "SIZE_FORMAT" new regions", expand_size, new_regions); 2103 bool success = _storage.expand_by(expand_size, ShenandoahAlwaysPreTouch); 2104 assert(success, "should always be able to expand by requested size"); 2105 2106 _num_regions = new_num_regions; 2107 2108 } 2109 2110 ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() : 2111 _heap(ShenandoahHeap::heap_no_check()) { 2112 } 2113 2114 void ShenandoahForwardedIsAliveClosure::init(ShenandoahHeap* heap) { 2115 _heap = heap; 2116 } 2117 2118 bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) { 2119 2120 assert(_heap != NULL, "sanity"); 2121 obj = ShenandoahBarrierSet::resolve_oop_static_not_null(obj); 2122 #ifdef ASSERT 2123 if (_heap->concurrent_mark_in_progress()) { 2124 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), "only query to-space"); 2125 } 2126 #endif 2127 assert(!oopDesc::is_null(obj), "null"); 2128 return _heap->is_marked_next(obj); 2129 } 2130 2131 void ShenandoahHeap::ref_processing_init() { 2132 MemRegion mr = reserved_region(); 2133 2134 isAlive.init(ShenandoahHeap::heap()); 2135 assert(_max_workers > 0, "Sanity"); 2136 2137 _ref_processor = 2138 new ReferenceProcessor(mr, // span 2139 ParallelRefProcEnabled, 2140 // mt processing 2141 _max_workers, 2142 // degree of mt processing 2143 true, 2144 // mt discovery 2145 _max_workers, 2146 // degree of mt discovery 2147 false, 2148 // Reference discovery is not atomic 2149 &isAlive); 2150 } 2151 2152 #ifdef ASSERT 2153 void ShenandoahHeap::set_from_region_protection(bool protect) { 2154 for (uint i = 0; i < _num_regions; i++) { 2155 ShenandoahHeapRegion* region = _ordered_regions->get(i); 2156 if (region != NULL && in_collection_set(region)) { 2157 if (protect) { 2158 region->memProtectionOn(); 2159 } else { 2160 region->memProtectionOff(); 2161 } 2162 } 2163 } 2164 } 2165 #endif 2166 2167 size_t ShenandoahHeap::num_regions() { 2168 return _num_regions; 2169 } 2170 2171 size_t ShenandoahHeap::max_regions() { 2172 return _max_regions; 2173 } 2174 2175 GCTracer* ShenandoahHeap::tracer() { 2176 return shenandoahPolicy()->tracer(); 2177 } 2178 2179 size_t ShenandoahHeap::tlab_used(Thread* thread) const { 2180 return _free_regions->used(); 2181 } 2182 2183 void ShenandoahHeap::cancel_concgc(GCCause::Cause cause) { 2184 if (try_cancel_concgc()) { 2185 log_info(gc)("Cancelling concurrent GC: %s", GCCause::to_string(cause)); 2186 _shenandoah_policy->report_concgc_cancelled(); 2187 } 2188 } 2189 2190 void ShenandoahHeap::cancel_concgc(ShenandoahCancelCause cause) { 2191 if (try_cancel_concgc()) { 2192 log_info(gc)("Cancelling concurrent GC: %s", cancel_cause_to_string(cause)); 2193 _shenandoah_policy->report_concgc_cancelled(); 2194 } 2195 } 2196 2197 const char* ShenandoahHeap::cancel_cause_to_string(ShenandoahCancelCause cause) { 2198 switch (cause) { 2199 case _oom_evacuation: 2200 return "Out of memory for evacuation"; 2201 case _vm_stop: 2202 return "Stopping VM"; 2203 default: 2204 return "Unknown"; 2205 } 2206 } 2207 2208 void ShenandoahHeap::clear_cancelled_concgc() { 2209 set_cancelled_concgc(false); 2210 } 2211 2212 uint ShenandoahHeap::max_workers() { 2213 return _max_workers; 2214 } 2215 2216 void ShenandoahHeap::stop() { 2217 // The shutdown sequence should be able to terminate when GC is running. 2218 2219 // Step 1. Notify control thread that we are in shutdown. 2220 // Note that we cannot do that with stop(), because stop() is blocking and waits for the actual shutdown. 2221 // Doing stop() here would wait for the normal GC cycle to complete, never falling through to cancel below. 2222 _concurrent_gc_thread->prepare_for_graceful_shutdown(); 2223 2224 // Step 2. Notify GC workers that we are cancelling GC. 2225 cancel_concgc(_vm_stop); 2226 2227 // Step 3. Wait until GC worker exits normally. 2228 _concurrent_gc_thread->stop(); 2229 } 2230 2231 void ShenandoahHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols) { 2232 2233 StringSymbolTableUnlinkTask shenandoah_unlink_task(is_alive, process_strings, process_symbols); 2234 workers()->run_task(&shenandoah_unlink_task); 2235 2236 // if (G1StringDedup::is_enabled()) { 2237 // G1StringDedup::unlink(is_alive); 2238 // } 2239 } 2240 2241 void ShenandoahHeap::set_need_update_refs(bool need_update_refs) { 2242 _need_update_refs = need_update_refs; 2243 } 2244 2245 //fixme this should be in heapregionset 2246 ShenandoahHeapRegion* ShenandoahHeap::next_compaction_region(const ShenandoahHeapRegion* r) { 2247 size_t region_idx = r->region_number() + 1; 2248 ShenandoahHeapRegion* next = _ordered_regions->get(region_idx); 2249 guarantee(next->region_number() == region_idx, "region number must match"); 2250 while (next->is_humongous()) { 2251 region_idx = next->region_number() + 1; 2252 next = _ordered_regions->get(region_idx); 2253 guarantee(next->region_number() == region_idx, "region number must match"); 2254 } 2255 return next; 2256 } 2257 2258 void ShenandoahHeap::set_region_in_collection_set(size_t region_index, bool b) { 2259 _in_cset_fast_test_base[region_index] = b; 2260 } 2261 2262 ShenandoahMonitoringSupport* ShenandoahHeap::monitoring_support() { 2263 return _monitoring_support; 2264 } 2265 2266 CMBitMap* ShenandoahHeap::complete_mark_bit_map() { 2267 return _complete_mark_bit_map; 2268 } 2269 2270 CMBitMap* ShenandoahHeap::next_mark_bit_map() { 2271 return _next_mark_bit_map; 2272 } 2273 2274 void ShenandoahHeap::add_free_region(ShenandoahHeapRegion* r) { 2275 _free_regions->add_region(r); 2276 } 2277 2278 void ShenandoahHeap::clear_free_regions() { 2279 _free_regions->clear(); 2280 } 2281 2282 address ShenandoahHeap::in_cset_fast_test_addr() { 2283 return (address) (ShenandoahHeap::heap()->_in_cset_fast_test); 2284 } 2285 2286 address ShenandoahHeap::cancelled_concgc_addr() { 2287 return (address) &(ShenandoahHeap::heap()->_cancelled_concgc); 2288 } 2289 2290 void ShenandoahHeap::clear_cset_fast_test() { 2291 assert(_in_cset_fast_test_base != NULL, "sanity"); 2292 memset(_in_cset_fast_test_base, false, 2293 _in_cset_fast_test_length * sizeof(bool)); 2294 } 2295 2296 size_t ShenandoahHeap::conservative_max_heap_alignment() { 2297 return ShenandoahMaxRegionSize; 2298 } 2299 2300 size_t ShenandoahHeap::bytes_allocated_since_cm() { 2301 return _bytes_allocated_since_cm; 2302 } 2303 2304 void ShenandoahHeap::set_bytes_allocated_since_cm(size_t bytes) { 2305 _bytes_allocated_since_cm = bytes; 2306 } 2307 2308 size_t ShenandoahHeap::max_allocated_gc() { 2309 return _max_allocated_gc; 2310 } 2311 2312 void ShenandoahHeap::set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr) { 2313 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift; 2314 _next_top_at_mark_starts[index] = addr; 2315 } 2316 2317 HeapWord* ShenandoahHeap::next_top_at_mark_start(HeapWord* region_base) { 2318 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift; 2319 return _next_top_at_mark_starts[index]; 2320 } 2321 2322 void ShenandoahHeap::set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr) { 2323 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift; 2324 _complete_top_at_mark_starts[index] = addr; 2325 } 2326 2327 HeapWord* ShenandoahHeap::complete_top_at_mark_start(HeapWord* region_base) { 2328 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift; 2329 return _complete_top_at_mark_starts[index]; 2330 } 2331 2332 void ShenandoahHeap::set_full_gc_in_progress(bool in_progress) { 2333 _full_gc_in_progress = in_progress; 2334 } 2335 2336 bool ShenandoahHeap::is_full_gc_in_progress() const { 2337 return _full_gc_in_progress; 2338 } 2339 2340 class NMethodOopInitializer : public OopClosure { 2341 private: 2342 ShenandoahHeap* _heap; 2343 public: 2344 NMethodOopInitializer() : _heap(ShenandoahHeap::heap()) { 2345 } 2346 2347 private: 2348 template <class T> 2349 inline void do_oop_work(T* p) { 2350 T o = oopDesc::load_heap_oop(p); 2351 if (! oopDesc::is_null(o)) { 2352 oop obj1 = oopDesc::decode_heap_oop_not_null(o); 2353 oop obj2 = oopDesc::bs()->write_barrier(obj1); 2354 if (! oopDesc::unsafe_equals(obj1, obj2)) { 2355 oopDesc::encode_store_heap_oop(p, obj2); 2356 } 2357 } 2358 } 2359 2360 public: 2361 void do_oop(oop* o) { 2362 do_oop_work(o); 2363 } 2364 void do_oop(narrowOop* o) { 2365 do_oop_work(o); 2366 } 2367 }; 2368 2369 void ShenandoahHeap::register_nmethod(nmethod* nm) { 2370 NMethodOopInitializer init; 2371 nm->oops_do(&init); 2372 nm->fix_oop_relocations(); 2373 } 2374 2375 void ShenandoahHeap::unregister_nmethod(nmethod* nm) { 2376 } 2377 2378 void ShenandoahHeap::pin_object(oop o) { 2379 heap_region_containing(o)->pin(); 2380 } 2381 2382 void ShenandoahHeap::unpin_object(oop o) { 2383 heap_region_containing(o)->unpin(); 2384 } 2385 2386 2387 GCTimer* ShenandoahHeap::gc_timer() const { 2388 return _gc_timer; 2389 } 2390 2391 class RecordAllRefsOopClosure: public ExtendedOopClosure { 2392 private: 2393 int _x; 2394 int *_matrix; 2395 int _num_regions; 2396 oop _p; 2397 2398 public: 2399 RecordAllRefsOopClosure(int *matrix, int x, size_t num_regions, oop p) : 2400 _matrix(matrix), _x(x), _num_regions(num_regions), _p(p) {} 2401 2402 template <class T> 2403 void do_oop_work(T* p) { 2404 oop o = oopDesc::load_decode_heap_oop(p); 2405 if (o != NULL) { 2406 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop() ) { 2407 int y = ShenandoahHeap::heap()->heap_region_containing(o)->region_number(); 2408 _matrix[_x * _num_regions + y]++; 2409 } 2410 } 2411 } 2412 void do_oop(oop* p) { 2413 do_oop_work(p); 2414 } 2415 2416 void do_oop(narrowOop* p) { 2417 do_oop_work(p); 2418 } 2419 2420 }; 2421 2422 class RecordAllRefsObjectClosure : public ObjectClosure { 2423 int *_matrix; 2424 size_t _num_regions; 2425 2426 public: 2427 RecordAllRefsObjectClosure(int *matrix, size_t num_regions) : 2428 _matrix(matrix), _num_regions(num_regions) {} 2429 2430 void do_object(oop p) { 2431 if (ShenandoahHeap::heap()->is_in(p) && ShenandoahHeap::heap()->is_marked_next(p) && p->is_oop()) { 2432 int x = ShenandoahHeap::heap()->heap_region_containing(p)->region_number(); 2433 RecordAllRefsOopClosure cl(_matrix, x, _num_regions, p); 2434 p->oop_iterate(&cl); 2435 } 2436 } 2437 }; 2438 void ShenandoahHeap::calculate_matrix(int* connections) { 2439 log_develop_trace(gc)("calculating matrix"); 2440 ensure_parsability(false); 2441 int num = num_regions(); 2442 2443 for (int i = 0; i < num; i++) { 2444 for (int j = 0; j < num; j++) { 2445 connections[i * num + j] = 0; 2446 } 2447 } 2448 2449 RecordAllRefsOopClosure cl(connections, 0, num, NULL); 2450 roots_iterate(&cl); 2451 2452 RecordAllRefsObjectClosure cl2(connections, num); 2453 object_iterate(&cl2); 2454 2455 } 2456 2457 void ShenandoahHeap::print_matrix(int* connections) { 2458 int num = num_regions(); 2459 int cs_regions = 0; 2460 int referenced = 0; 2461 2462 for (int i = 0; i < num; i++) { 2463 size_t liveData = ShenandoahHeap::heap()->regions()->get(i)->get_live_data_bytes(); 2464 2465 int numReferencedRegions = 0; 2466 int numReferencedByRegions = 0; 2467 2468 for (int j = 0; j < num; j++) { 2469 if (connections[i * num + j] > 0) 2470 numReferencedRegions++; 2471 2472 if (connections [j * num + i] > 0) 2473 numReferencedByRegions++; 2474 2475 cs_regions++; 2476 referenced += numReferencedByRegions; 2477 } 2478 2479 if (ShenandoahHeap::heap()->regions()->get(i)->has_live()) { 2480 tty->print("Region %d is referenced by %d regions {", 2481 i, numReferencedByRegions); 2482 int col_count = 0; 2483 for (int j = 0; j < num; j++) { 2484 int foo = connections[j * num + i]; 2485 if (foo > 0) { 2486 col_count++; 2487 if ((col_count % 10) == 0) 2488 tty->print("\n"); 2489 tty->print("%d(%d), ", j,foo); 2490 } 2491 } 2492 tty->print("} \n"); 2493 } 2494 } 2495 2496 double avg = (double)referenced / (double) cs_regions; 2497 tty->print("Average Number of regions scanned / region = %lf\n", avg); 2498 } 2499 2500 class ShenandoahCountGarbageClosure : public ShenandoahHeapRegionClosure { 2501 private: 2502 size_t _garbage; 2503 public: 2504 ShenandoahCountGarbageClosure() : _garbage(0) { 2505 } 2506 2507 bool doHeapRegion(ShenandoahHeapRegion* r) { 2508 if (! r->is_humongous() && ! r->is_pinned() && ! r->in_collection_set()) { 2509 _garbage += r->garbage(); 2510 } 2511 return false; 2512 } 2513 2514 size_t garbage() { 2515 return _garbage; 2516 } 2517 }; 2518 2519 size_t ShenandoahHeap::garbage() { 2520 ShenandoahCountGarbageClosure cl; 2521 heap_region_iterate(&cl); 2522 return cl.garbage(); 2523 } 2524 2525 ShenandoahConnectionMatrix* ShenandoahHeap::connection_matrix() { 2526 return _connection_matrix; 2527 } 2528 2529 #ifdef ASSERT 2530 void ShenandoahHeap::assert_heaplock_owned_by_current_thread() { 2531 assert(_heap_lock == locked, "must be locked"); 2532 assert(_heap_lock_owner == Thread::current(), "must be owned by current thread"); 2533 } 2534 2535 void ShenandoahHeap::assert_heaplock_or_safepoint() { 2536 Thread* thr = Thread::current(); 2537 assert((_heap_lock == locked && _heap_lock_owner == thr) || 2538 (SafepointSynchronize::is_at_safepoint() && thr->is_VM_thread()), 2539 "must own heap lock or by VM thread at safepoint"); 2540 } 2541 2542 #endif