1 /* 2 * Copyright (c) 2015, 2019, 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 _unload(&_workers), 73 _serviceability(heap_min_size(), heap_max_size()) { 74 // Install global heap instance 75 assert(_heap == NULL, "Already initialized"); 76 _heap = this; 77 78 // Update statistics 79 ZStatHeap::set_at_initialize(heap_max_size(), heap_max_reserve_size()); 80 } 81 82 size_t ZHeap::heap_min_size() const { 83 const size_t aligned_min_size = align_up(InitialHeapSize, ZGranuleSize); 84 return MIN2(aligned_min_size, heap_max_size()); 85 } 86 87 size_t ZHeap::heap_max_size() const { 88 const size_t aligned_max_size = align_up(MaxHeapSize, ZGranuleSize); 89 return MIN2(aligned_max_size, ZAddressOffsetMax); 90 } 91 92 size_t ZHeap::heap_max_reserve_size() const { 93 // Reserve one small page per worker plus one shared medium page. This is still just 94 // an estimate and doesn't guarantee that we can't run out of memory during relocation. 95 const size_t max_reserve_size = (_workers.nworkers() * ZPageSizeSmall) + ZPageSizeMedium; 96 return MIN2(max_reserve_size, heap_max_size()); 97 } 98 99 bool ZHeap::is_initialized() const { 100 return _page_allocator.is_initialized() && _mark.is_initialized(); 101 } 102 103 size_t ZHeap::min_capacity() const { 104 return heap_min_size(); 105 } 106 107 size_t ZHeap::max_capacity() const { 108 return _page_allocator.max_capacity(); 109 } 110 111 size_t ZHeap::current_max_capacity() const { 112 return _page_allocator.current_max_capacity(); 113 } 114 115 size_t ZHeap::capacity() const { 116 return _page_allocator.capacity(); 117 } 118 119 size_t ZHeap::max_reserve() const { 120 return _page_allocator.max_reserve(); 121 } 122 123 size_t ZHeap::used_high() const { 124 return _page_allocator.used_high(); 125 } 126 127 size_t ZHeap::used_low() const { 128 return _page_allocator.used_low(); 129 } 130 131 size_t ZHeap::used() const { 132 return _page_allocator.used(); 133 } 134 135 size_t ZHeap::allocated() const { 136 return _page_allocator.allocated(); 137 } 138 139 size_t ZHeap::reclaimed() const { 140 return _page_allocator.reclaimed(); 141 } 142 143 size_t ZHeap::tlab_capacity() const { 144 return capacity(); 145 } 146 147 size_t ZHeap::tlab_used() const { 148 return _object_allocator.used(); 149 } 150 151 size_t ZHeap::max_tlab_size() const { 152 return ZObjectSizeLimitSmall; 153 } 154 155 size_t ZHeap::unsafe_max_tlab_alloc() const { 156 size_t size = _object_allocator.remaining(); 157 158 if (size < MinTLABSize) { 159 // The remaining space in the allocator is not enough to 160 // fit the smallest possible TLAB. This means that the next 161 // TLAB allocation will force the allocator to get a new 162 // backing page anyway, which in turn means that we can then 163 // fit the largest possible TLAB. 164 size = max_tlab_size(); 165 } 166 167 return MIN2(size, max_tlab_size()); 168 } 169 170 bool ZHeap::is_in(uintptr_t addr) const { 171 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) { 172 return false; 173 } 174 175 const ZPage* const page = _pagetable.get(addr); 176 if (page != NULL) { 177 return page->is_in(addr); 178 } 179 180 return false; 181 } 182 183 uintptr_t ZHeap::block_start(uintptr_t addr) const { 184 const ZPage* const page = _pagetable.get(addr); 185 return page->block_start(addr); 186 } 187 188 bool ZHeap::block_is_obj(uintptr_t addr) const { 189 const ZPage* const page = _pagetable.get(addr); 190 return page->block_is_obj(addr); 191 } 192 193 uint ZHeap::nconcurrent_worker_threads() const { 194 return _workers.nconcurrent(); 195 } 196 197 uint ZHeap::nconcurrent_no_boost_worker_threads() const { 198 return _workers.nconcurrent_no_boost(); 199 } 200 201 void ZHeap::set_boost_worker_threads(bool boost) { 202 _workers.set_boost(boost); 203 } 204 205 void ZHeap::worker_threads_do(ThreadClosure* tc) const { 206 _workers.threads_do(tc); 207 } 208 209 void ZHeap::print_worker_threads_on(outputStream* st) const { 210 _workers.print_threads_on(st); 211 } 212 213 void ZHeap::out_of_memory() { 214 ResourceMark rm; 215 216 ZStatInc(ZCounterOutOfMemory); 217 log_info(gc)("Out Of Memory (%s)", Thread::current()->name()); 218 } 219 220 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) { 221 ZPage* const page = _page_allocator.alloc_page(type, size, flags); 222 if (page != NULL) { 223 // Update pagetable 224 _pagetable.insert(page); 225 } 226 227 return page; 228 } 229 230 void ZHeap::undo_alloc_page(ZPage* page) { 231 assert(page->is_allocating(), "Invalid page state"); 232 233 ZStatInc(ZCounterUndoPageAllocation); 234 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT, 235 ZThread::id(), ZThread::name(), p2i(page), page->size()); 236 237 release_page(page, false /* reclaimed */); 238 } 239 240 bool ZHeap::retain_page(ZPage* page) { 241 return page->inc_refcount(); 242 } 243 244 void ZHeap::release_page(ZPage* page, bool reclaimed) { 245 if (page->dec_refcount()) { 246 _page_allocator.free_page(page, reclaimed); 247 } 248 } 249 250 void ZHeap::flip_views() { 251 // For debugging only 252 if (ZUnmapBadViews) { 253 // Flip pages 254 ZPageTableIterator iter(&_pagetable); 255 for (ZPage* page; iter.next(&page);) { 256 if (!page->is_detached()) { 257 _page_allocator.flip_page(page); 258 } 259 } 260 261 // Flip pre-mapped memory 262 _page_allocator.flip_pre_mapped(); 263 } 264 } 265 266 void ZHeap::mark_start() { 267 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 268 269 // Update statistics 270 ZStatSample(ZSamplerHeapUsedBeforeMark, used()); 271 272 // Flip address view 273 ZAddressMasks::flip_to_marked(); 274 flip_views(); 275 276 // Retire allocating pages 277 _object_allocator.retire_pages(); 278 279 // Reset allocated/reclaimed/used statistics 280 _page_allocator.reset_statistics(); 281 282 // Reset encountered/dropped/enqueued statistics 283 _reference_processor.reset_statistics(); 284 285 // Enter mark phase 286 ZGlobalPhase = ZPhaseMark; 287 288 // Reset marking information and mark roots 289 _mark.start(); 290 291 // Update statistics 292 ZStatHeap::set_at_mark_start(capacity(), used()); 293 } 294 295 void ZHeap::mark(bool initial) { 296 _mark.mark(initial); 297 } 298 299 void ZHeap::mark_flush_and_free(Thread* thread) { 300 _mark.flush_and_free(thread); 301 } 302 303 class ZFixupPartialLoadsClosure : public ZRootsIteratorClosure { 304 public: 305 virtual void do_oop(oop* p) { 306 ZBarrier::mark_barrier_on_root_oop_field(p); 307 } 308 309 virtual void do_oop(narrowOop* p) { 310 ShouldNotReachHere(); 311 } 312 }; 313 314 class ZFixupPartialLoadsTask : public ZTask { 315 private: 316 ZThreadRootsIterator _thread_roots; 317 318 public: 319 ZFixupPartialLoadsTask() : 320 ZTask("ZFixupPartialLoadsTask"), 321 _thread_roots() {} 322 323 virtual void work() { 324 ZFixupPartialLoadsClosure cl; 325 _thread_roots.oops_do(&cl); 326 } 327 }; 328 329 void ZHeap::fixup_partial_loads() { 330 ZFixupPartialLoadsTask task; 331 _workers.run_parallel(&task); 332 } 333 334 bool ZHeap::mark_end() { 335 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 336 337 // C2 can generate code where a safepoint poll is inserted 338 // between a load and the associated load barrier. To handle 339 // this case we need to rescan the thread stack here to make 340 // sure such oops are marked. 341 fixup_partial_loads(); 342 343 // Try end marking 344 if (!_mark.end()) { 345 // Marking not completed, continue concurrent mark 346 return false; 347 } 348 349 // Enter mark completed phase 350 ZGlobalPhase = ZPhaseMarkCompleted; 351 352 // Update statistics 353 ZStatSample(ZSamplerHeapUsedAfterMark, used()); 354 ZStatHeap::set_at_mark_end(capacity(), allocated(), used()); 355 356 // Block resurrection of weak/phantom references 357 ZResurrection::block(); 358 359 // Process weak roots 360 _weak_roots_processor.process_weak_roots(); 361 362 // Prepare to unload unused classes and code 363 _unload.prepare(); 364 365 return true; 366 } 367 368 void ZHeap::set_soft_reference_policy(bool clear) { 369 _reference_processor.set_soft_reference_policy(clear); 370 } 371 372 void ZHeap::process_non_strong_references() { 373 // Process Soft/Weak/Final/PhantomReferences 374 _reference_processor.process_references(); 375 376 // Process concurrent weak roots 377 _weak_roots_processor.process_concurrent_weak_roots(); 378 379 // Unload unused classes and code 380 _unload.unload(); 381 382 // Unblock resurrection of weak/phantom references 383 ZResurrection::unblock(); 384 385 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this 386 // must be done after unblocking resurrection. Otherwise the 387 // Finalizer thread could call Reference.get() on the Finalizers 388 // that were just enqueued, which would incorrectly return null 389 // during the resurrection block window, since such referents 390 // are only Finalizable marked. 391 _reference_processor.enqueue_references(); 392 } 393 394 void ZHeap::destroy_detached_pages() { 395 ZList<ZPage> list; 396 397 _page_allocator.flush_detached_pages(&list); 398 399 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) { 400 // Remove pagetable entry 401 _pagetable.remove(page); 402 403 // Delete the page 404 _page_allocator.destroy_page(page); 405 } 406 } 407 408 void ZHeap::select_relocation_set() { 409 // Register relocatable pages with selector 410 ZRelocationSetSelector selector; 411 ZPageTableIterator iter(&_pagetable); 412 for (ZPage* page; iter.next(&page);) { 413 if (!page->is_relocatable()) { 414 // Not relocatable, don't register 415 continue; 416 } 417 418 if (page->is_marked()) { 419 // Register live page 420 selector.register_live_page(page); 421 } else { 422 // Register garbage page 423 selector.register_garbage_page(page); 424 425 // Reclaim page immediately 426 release_page(page, true /* reclaimed */); 427 } 428 } 429 430 // Select pages to relocate 431 selector.select(&_relocation_set); 432 433 // Update statistics 434 ZStatRelocation::set_at_select_relocation_set(selector.relocating()); 435 ZStatHeap::set_at_select_relocation_set(selector.live(), 436 selector.garbage(), 437 reclaimed()); 438 } 439 440 void ZHeap::prepare_relocation_set() { 441 ZRelocationSetIterator iter(&_relocation_set); 442 for (ZPage* page; iter.next(&page);) { 443 // Prepare for relocation 444 page->set_forwarding(); 445 446 // Update pagetable 447 _pagetable.set_relocating(page); 448 } 449 } 450 451 void ZHeap::reset_relocation_set() { 452 ZRelocationSetIterator iter(&_relocation_set); 453 for (ZPage* page; iter.next(&page);) { 454 // Reset relocation information 455 page->reset_forwarding(); 456 457 // Update pagetable 458 _pagetable.clear_relocating(page); 459 } 460 } 461 462 void ZHeap::relocate_start() { 463 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 464 465 // Finish unloading of classes and code 466 _unload.finish(); 467 468 // Flip address view 469 ZAddressMasks::flip_to_remapped(); 470 flip_views(); 471 472 // Enter relocate phase 473 ZGlobalPhase = ZPhaseRelocate; 474 475 // Update statistics 476 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used()); 477 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used()); 478 479 // Remap/Relocate roots 480 _relocate.start(); 481 } 482 483 uintptr_t ZHeap::relocate_object(uintptr_t addr) { 484 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed"); 485 ZPage* const page = _pagetable.get(addr); 486 const bool retained = retain_page(page); 487 const uintptr_t new_addr = page->relocate_object(addr); 488 if (retained) { 489 release_page(page, true /* reclaimed */); 490 } 491 492 return new_addr; 493 } 494 495 uintptr_t ZHeap::forward_object(uintptr_t addr) { 496 assert(ZGlobalPhase == ZPhaseMark || 497 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed"); 498 ZPage* const page = _pagetable.get(addr); 499 return page->forward_object(addr); 500 } 501 502 void ZHeap::relocate() { 503 // Relocate relocation set 504 const bool success = _relocate.relocate(&_relocation_set); 505 506 // Update statistics 507 ZStatSample(ZSamplerHeapUsedAfterRelocation, used()); 508 ZStatRelocation::set_at_relocate_end(success); 509 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(), 510 used(), used_high(), used_low()); 511 } 512 513 void ZHeap::object_iterate(ObjectClosure* cl, bool visit_referents) { 514 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 515 516 ZHeapIterator iter(visit_referents); 517 iter.objects_do(cl); 518 } 519 520 void ZHeap::serviceability_initialize() { 521 _serviceability.initialize(); 522 } 523 524 GCMemoryManager* ZHeap::serviceability_memory_manager() { 525 return _serviceability.memory_manager(); 526 } 527 528 MemoryPool* ZHeap::serviceability_memory_pool() { 529 return _serviceability.memory_pool(); 530 } 531 532 ZServiceabilityCounters* ZHeap::serviceability_counters() { 533 return _serviceability.counters(); 534 } 535 536 void ZHeap::print_on(outputStream* st) const { 537 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M", 538 used() / M, 539 capacity() / M, 540 max_capacity() / M); 541 MetaspaceUtils::print_on(st); 542 } 543 544 void ZHeap::print_extended_on(outputStream* st) const { 545 print_on(st); 546 st->cr(); 547 548 ZPageTableIterator iter(&_pagetable); 549 for (ZPage* page; iter.next(&page);) { 550 page->print_on(st); 551 } 552 553 st->cr(); 554 } 555 556 class ZVerifyRootsTask : public ZTask { 557 private: 558 ZRootsIterator _strong_roots; 559 ZWeakRootsIterator _weak_roots; 560 561 public: 562 ZVerifyRootsTask() : 563 ZTask("ZVerifyRootsTask"), 564 _strong_roots(), 565 _weak_roots() {} 566 567 virtual void work() { 568 ZVerifyOopClosure cl; 569 _strong_roots.oops_do(&cl); 570 _weak_roots.oops_do(&cl); 571 } 572 }; 573 574 void ZHeap::verify() { 575 // Heap verification can only be done between mark end and 576 // relocate start. This is the only window where all oop are 577 // good and the whole heap is in a consistent state. 578 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase"); 579 580 { 581 ZVerifyRootsTask task; 582 _workers.run_parallel(&task); 583 } 584 585 { 586 ZVerifyObjectClosure cl; 587 object_iterate(&cl, false /* visit_referents */); 588 } 589 }