1 /* 2 * Copyright (c) 2015, 2018, 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 #include "precompiled.hpp" 25 #include "gc/shared/oopStorage.hpp" 26 #include "gc/z/zAddress.hpp" 27 #include "gc/z/zGlobals.hpp" 28 #include "gc/z/zHeap.inline.hpp" 29 #include "gc/z/zHeapIterator.hpp" 30 #include "gc/z/zList.inline.hpp" 31 #include "gc/z/zLock.inline.hpp" 32 #include "gc/z/zMark.inline.hpp" 33 #include "gc/z/zOopClosures.inline.hpp" 34 #include "gc/z/zPage.inline.hpp" 35 #include "gc/z/zPageTable.inline.hpp" 36 #include "gc/z/zRelocationSet.inline.hpp" 37 #include "gc/z/zResurrection.hpp" 38 #include "gc/z/zRootsIterator.hpp" 39 #include "gc/z/zStat.hpp" 40 #include "gc/z/zTask.hpp" 41 #include "gc/z/zThread.hpp" 42 #include "gc/z/zTracer.inline.hpp" 43 #include "gc/z/zVirtualMemory.inline.hpp" 44 #include "gc/z/zWorkers.inline.hpp" 45 #include "logging/log.hpp" 46 #include "memory/resourceArea.hpp" 47 #include "oops/oop.inline.hpp" 48 #include "runtime/safepoint.hpp" 49 #include "runtime/thread.hpp" 50 #include "utilities/align.hpp" 51 #include "utilities/debug.hpp" 52 53 static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes); 54 static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes); 55 static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes); 56 static const ZStatSampler ZSamplerHeapUsedAfterRelocation("Memory", "Heap Used After Relocation", ZStatUnitBytes); 57 static const ZStatCounter ZCounterUndoPageAllocation("Memory", "Undo Page Allocation", ZStatUnitOpsPerSecond); 58 static const ZStatCounter ZCounterOutOfMemory("Memory", "Out Of Memory", ZStatUnitOpsPerSecond); 59 60 ZHeap* ZHeap::_heap = NULL; 61 62 ZHeap::ZHeap() : 63 _workers(), 64 _object_allocator(_workers.nworkers()), 65 _page_allocator(heap_min_size(), heap_max_size(), heap_max_reserve_size()), 66 _pagetable(), 67 _mark(&_workers, &_pagetable), 68 _reference_processor(&_workers), 69 _weak_roots_processor(&_workers), 70 _relocate(&_workers), 71 _relocation_set(), 72 _serviceability(heap_min_size(), heap_max_size()) { 73 // Install global heap instance 74 assert(_heap == NULL, "Already initialized"); 75 _heap = this; 76 77 // Update statistics 78 ZStatHeap::set_at_initialize(heap_max_size(), heap_max_reserve_size()); 79 } 80 81 size_t ZHeap::heap_min_size() const { 82 const size_t aligned_min_size = align_up(InitialHeapSize, ZPageSizeMin); 83 return MIN2(aligned_min_size, heap_max_size()); 84 } 85 86 size_t ZHeap::heap_max_size() const { 87 const size_t aligned_max_size = align_up(MaxHeapSize, ZPageSizeMin); 88 return MIN2(aligned_max_size, ZAddressOffsetMax); 89 } 90 91 size_t ZHeap::heap_max_reserve_size() const { 92 // Reserve one small page per worker plus one shared medium page. This is still just 93 // an estimate and doesn't guarantee that we can't run out of memory during relocation. 94 const size_t max_reserve_size = (_workers.nworkers() * ZPageSizeSmall) + ZPageSizeMedium; 95 return MIN2(max_reserve_size, heap_max_size()); 96 } 97 98 bool ZHeap::is_initialized() const { 99 return _page_allocator.is_initialized() && _mark.is_initialized(); 100 } 101 102 size_t ZHeap::min_capacity() const { 103 return heap_min_size(); 104 } 105 106 size_t ZHeap::max_capacity() const { 107 return _page_allocator.max_capacity(); 108 } 109 110 size_t ZHeap::current_max_capacity() const { 111 return _page_allocator.current_max_capacity(); 112 } 113 114 size_t ZHeap::capacity() const { 115 return _page_allocator.capacity(); 116 } 117 118 size_t ZHeap::max_reserve() const { 119 return _page_allocator.max_reserve(); 120 } 121 122 size_t ZHeap::used_high() const { 123 return _page_allocator.used_high(); 124 } 125 126 size_t ZHeap::used_low() const { 127 return _page_allocator.used_low(); 128 } 129 130 size_t ZHeap::used() const { 131 return _page_allocator.used(); 132 } 133 134 size_t ZHeap::allocated() const { 135 return _page_allocator.allocated(); 136 } 137 138 size_t ZHeap::reclaimed() const { 139 return _page_allocator.reclaimed(); 140 } 141 142 size_t ZHeap::tlab_capacity() const { 143 return capacity(); 144 } 145 146 size_t ZHeap::tlab_used() const { 147 return _object_allocator.used(); 148 } 149 150 size_t ZHeap::max_tlab_size() const { 151 return ZObjectSizeLimitSmall; 152 } 153 154 size_t ZHeap::unsafe_max_tlab_alloc() const { 155 size_t size = _object_allocator.remaining(); 156 157 if (size < MinTLABSize) { 158 // The remaining space in the allocator is not enough to 159 // fit the smallest possible TLAB. This means that the next 160 // TLAB allocation will force the allocator to get a new 161 // backing page anyway, which in turn means that we can then 162 // fit the largest possible TLAB. 163 size = max_tlab_size(); 164 } 165 166 return MIN2(size, max_tlab_size()); 167 } 168 169 bool ZHeap::is_in(uintptr_t addr) const { 170 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) { 171 return false; 172 } 173 174 const ZPage* const page = _pagetable.get(addr); 175 if (page != NULL) { 176 return page->is_in(addr); 177 } 178 179 return false; 180 } 181 182 uintptr_t ZHeap::block_start(uintptr_t addr) const { 183 const ZPage* const page = _pagetable.get(addr); 184 return page->block_start(addr); 185 } 186 187 size_t ZHeap::block_size(uintptr_t addr) const { 188 const ZPage* const page = _pagetable.get(addr); 189 return page->block_size(addr); 190 } 191 192 bool ZHeap::block_is_obj(uintptr_t addr) const { 193 const ZPage* const page = _pagetable.get(addr); 194 return page->block_is_obj(addr); 195 } 196 197 uint ZHeap::nconcurrent_worker_threads() const { 198 return _workers.nconcurrent(); 199 } 200 201 uint ZHeap::nconcurrent_no_boost_worker_threads() const { 202 return _workers.nconcurrent_no_boost(); 203 } 204 205 void ZHeap::set_boost_worker_threads(bool boost) { 206 _workers.set_boost(boost); 207 } 208 209 void ZHeap::worker_threads_do(ThreadClosure* tc) const { 210 _workers.threads_do(tc); 211 } 212 213 void ZHeap::print_worker_threads_on(outputStream* st) const { 214 _workers.print_threads_on(st); 215 } 216 217 void ZHeap::out_of_memory() { 218 ResourceMark rm; 219 220 ZStatInc(ZCounterOutOfMemory); 221 log_info(gc)("Out Of Memory (%s)", Thread::current()->name()); 222 } 223 224 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) { 225 ZPage* const page = _page_allocator.alloc_page(type, size, flags); 226 if (page != NULL) { 227 // Update pagetable 228 _pagetable.insert(page); 229 } 230 231 return page; 232 } 233 234 void ZHeap::undo_alloc_page(ZPage* page) { 235 assert(page->is_allocating(), "Invalid page state"); 236 237 ZStatInc(ZCounterUndoPageAllocation); 238 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT, 239 ZThread::id(), ZThread::name(), p2i(page), page->size()); 240 241 release_page(page, false /* reclaimed */); 242 } 243 244 bool ZHeap::retain_page(ZPage* page) { 245 return page->inc_refcount(); 246 } 247 248 void ZHeap::release_page(ZPage* page, bool reclaimed) { 249 if (page->dec_refcount()) { 250 _page_allocator.free_page(page, reclaimed); 251 } 252 } 253 254 void ZHeap::flip_views() { 255 // For debugging only 256 if (ZUnmapBadViews) { 257 // Flip pages 258 ZPageTableIterator iter(&_pagetable); 259 for (ZPage* page; iter.next(&page);) { 260 if (!page->is_detached()) { 261 _page_allocator.flip_page(page); 262 } 263 } 264 265 // Flip pre-mapped memory 266 _page_allocator.flip_pre_mapped(); 267 } 268 } 269 270 void ZHeap::mark_start() { 271 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 272 273 // Update statistics 274 ZStatSample(ZSamplerHeapUsedBeforeMark, used()); 275 276 // Retire TLABs 277 _object_allocator.retire_tlabs(); 278 279 // Flip address view 280 ZAddressMasks::flip_to_marked(); 281 flip_views(); 282 283 // Reset allocated/reclaimed/used statistics 284 _page_allocator.reset_statistics(); 285 286 // Reset encountered/dropped/enqueued statistics 287 _reference_processor.reset_statistics(); 288 289 // Enter mark phase 290 ZGlobalPhase = ZPhaseMark; 291 292 // Reset marking information and mark roots 293 _mark.start(); 294 295 // Update statistics 296 ZStatHeap::set_at_mark_start(capacity(), used()); 297 } 298 299 void ZHeap::mark(bool initial) { 300 _mark.mark(initial); 301 } 302 303 void ZHeap::mark_flush_and_free(Thread* thread) { 304 _mark.flush_and_free(thread); 305 } 306 307 class ZFixupPartialLoadsTask : public ZTask { 308 private: 309 ZThreadRootsIterator _thread_roots; 310 311 public: 312 ZFixupPartialLoadsTask() : 313 ZTask("ZFixupPartialLoadsTask"), 314 _thread_roots() {} 315 316 virtual void work() { 317 ZMarkRootOopClosure cl; 318 _thread_roots.oops_do(&cl); 319 } 320 }; 321 322 void ZHeap::fixup_partial_loads() { 323 ZFixupPartialLoadsTask task; 324 _workers.run_parallel(&task); 325 } 326 327 bool ZHeap::mark_end() { 328 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 329 330 // C2 can generate code where a safepoint poll is inserted 331 // between a load and the associated load barrier. To handle 332 // this case we need to rescan the thread stack here to make 333 // sure such oops are marked. 334 fixup_partial_loads(); 335 336 // Try end marking 337 if (!_mark.end()) { 338 // Marking not completed, continue concurrent mark 339 return false; 340 } 341 342 // Enter mark completed phase 343 ZGlobalPhase = ZPhaseMarkCompleted; 344 345 // Resize metaspace 346 MetaspaceGC::compute_new_size(); 347 348 // Update statistics 349 ZStatSample(ZSamplerHeapUsedAfterMark, used()); 350 ZStatHeap::set_at_mark_end(capacity(), allocated(), used()); 351 352 // Block resurrection of weak/phantom references 353 ZResurrection::block(); 354 355 // Process weak roots 356 _weak_roots_processor.process_weak_roots(); 357 358 // Verification 359 if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) { 360 Universe::verify(); 361 } 362 363 return true; 364 } 365 366 void ZHeap::set_soft_reference_policy(bool clear) { 367 _reference_processor.set_soft_reference_policy(clear); 368 } 369 370 void ZHeap::process_non_strong_references() { 371 // Process Soft/Weak/Final/PhantomReferences 372 _reference_processor.process_references(); 373 374 // Process concurrent weak roots 375 _weak_roots_processor.process_concurrent_weak_roots(); 376 377 // Unblock resurrection of weak/phantom references 378 ZResurrection::unblock(); 379 380 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this 381 // must be done after unblocking resurrection. Otherwise the 382 // Finalizer thread could call Reference.get() on the Finalizers 383 // that were just enqueued, which would incorrectly return null 384 // during the resurrection block window, since such referents 385 // are only Finalizable marked. 386 _reference_processor.enqueue_references(); 387 } 388 389 void ZHeap::destroy_detached_pages() { 390 ZList<ZPage> list; 391 392 _page_allocator.flush_detached_pages(&list); 393 394 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) { 395 // Remove pagetable entry 396 _pagetable.remove(page); 397 398 // Delete the page 399 _page_allocator.destroy_page(page); 400 } 401 } 402 403 void ZHeap::select_relocation_set() { 404 // Register relocatable pages with selector 405 ZRelocationSetSelector selector; 406 ZPageTableIterator iter(&_pagetable); 407 for (ZPage* page; iter.next(&page);) { 408 if (!page->is_relocatable()) { 409 // Not relocatable, don't register 410 continue; 411 } 412 413 if (page->is_marked()) { 414 // Register live page 415 selector.register_live_page(page); 416 } else { 417 // Register garbage page 418 selector.register_garbage_page(page); 419 420 // Reclaim page immediately 421 release_page(page, true /* reclaimed */); 422 } 423 } 424 425 // Select pages to relocate 426 selector.select(&_relocation_set); 427 428 // Update statistics 429 ZStatRelocation::set_at_select_relocation_set(selector.relocating()); 430 ZStatHeap::set_at_select_relocation_set(selector.live(), 431 selector.garbage(), 432 reclaimed()); 433 } 434 435 void ZHeap::prepare_relocation_set() { 436 ZRelocationSetIterator iter(&_relocation_set); 437 for (ZPage* page; iter.next(&page);) { 438 // Prepare for relocation 439 page->set_forwarding(); 440 441 // Update pagetable 442 _pagetable.set_relocating(page); 443 } 444 } 445 446 void ZHeap::reset_relocation_set() { 447 ZRelocationSetIterator iter(&_relocation_set); 448 for (ZPage* page; iter.next(&page);) { 449 // Reset relocation information 450 page->reset_forwarding(); 451 452 // Update pagetable 453 _pagetable.clear_relocating(page); 454 } 455 } 456 457 void ZHeap::relocate_start() { 458 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 459 460 // Update statistics 461 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used()); 462 463 // Flip address view 464 ZAddressMasks::flip_to_remapped(); 465 flip_views(); 466 467 // Remap TLABs 468 _object_allocator.remap_tlabs(); 469 470 // Enter relocate phase 471 ZGlobalPhase = ZPhaseRelocate; 472 473 // Update statistics 474 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used()); 475 476 // Remap/Relocate roots 477 _relocate.start(); 478 } 479 480 uintptr_t ZHeap::relocate_object(uintptr_t addr) { 481 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed"); 482 ZPage* const page = _pagetable.get(addr); 483 const bool retained = retain_page(page); 484 const uintptr_t new_addr = page->relocate_object(addr); 485 if (retained) { 486 release_page(page, true /* reclaimed */); 487 } 488 489 return new_addr; 490 } 491 492 uintptr_t ZHeap::forward_object(uintptr_t addr) { 493 assert(ZGlobalPhase == ZPhaseMark || 494 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed"); 495 ZPage* const page = _pagetable.get(addr); 496 return page->forward_object(addr); 497 } 498 499 void ZHeap::relocate() { 500 // Relocate relocation set 501 const bool success = _relocate.relocate(&_relocation_set); 502 503 // Update statistics 504 ZStatSample(ZSamplerHeapUsedAfterRelocation, used()); 505 ZStatRelocation::set_at_relocate_end(success); 506 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(), 507 used(), used_high(), used_low()); 508 } 509 510 void ZHeap::object_iterate(ObjectClosure* cl, bool visit_referents) { 511 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 512 513 ZHeapIterator iter(visit_referents); 514 iter.objects_do(cl); 515 } 516 517 void ZHeap::serviceability_initialize() { 518 _serviceability.initialize(); 519 } 520 521 GCMemoryManager* ZHeap::serviceability_memory_manager() { 522 return _serviceability.memory_manager(); 523 } 524 525 MemoryPool* ZHeap::serviceability_memory_pool() { 526 return _serviceability.memory_pool(); 527 } 528 529 ZServiceabilityCounters* ZHeap::serviceability_counters() { 530 return _serviceability.counters(); 531 } 532 533 void ZHeap::print_on(outputStream* st) const { 534 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M", 535 used() / M, 536 capacity() / M, 537 max_capacity() / M); 538 MetaspaceUtils::print_on(st); 539 } 540 541 void ZHeap::print_extended_on(outputStream* st) const { 542 print_on(st); 543 st->cr(); 544 545 ZPageTableIterator iter(&_pagetable); 546 for (ZPage* page; iter.next(&page);) { 547 page->print_on(st); 548 } 549 550 st->cr(); 551 } 552 553 class ZVerifyRootsTask : public ZTask { 554 private: 555 ZRootsIterator _strong_roots; 556 ZWeakRootsIterator _weak_roots; 557 558 public: 559 ZVerifyRootsTask() : 560 ZTask("ZVerifyRootsTask"), 561 _strong_roots(), 562 _weak_roots() {} 563 564 virtual void work() { 565 ZVerifyRootOopClosure cl; 566 _strong_roots.oops_do(&cl); 567 _weak_roots.oops_do(&cl); 568 } 569 }; 570 571 void ZHeap::verify() { 572 // Heap verification can only be done between mark end and 573 // relocate start. This is the only window where all oop are 574 // good and the whole heap is in a consistent state. 575 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase"); 576 577 { 578 ZVerifyRootsTask task; 579 _workers.run_parallel(&task); 580 } 581 582 { 583 ZVerifyObjectClosure cl; 584 object_iterate(&cl, false /* visit_referents */); 585 } 586 }