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 "oops/oop.inline.hpp" 47 #include "runtime/safepoint.hpp" 48 #include "runtime/thread.hpp" 49 #include "utilities/align.hpp" 50 #include "utilities/debug.hpp" 51 52 static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes); 53 static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes); 54 static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes); 55 static const ZStatSampler ZSamplerHeapUsedAfterRelocation("Memory", "Heap Used After Relocation", ZStatUnitBytes); 56 static const ZStatCounter ZCounterUndoPageAllocation("Memory", "Undo Page Allocation", ZStatUnitOpsPerSecond); 57 static const ZStatCounter ZCounterOutOfMemory("Memory", "Out Of Memory", ZStatUnitOpsPerSecond); 58 59 ZHeap* ZHeap::_heap = NULL; 60 61 ZHeap::ZHeap() : 62 _initialize(), 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(); 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::capacity() const { 111 return _page_allocator.capacity(); 112 } 113 114 size_t ZHeap::max_reserve() const { 115 return _page_allocator.max_reserve(); 116 } 117 118 size_t ZHeap::used_high() const { 119 return _page_allocator.used_high(); 120 } 121 122 size_t ZHeap::used_low() const { 123 return _page_allocator.used_low(); 124 } 125 126 size_t ZHeap::used() const { 127 return _page_allocator.used(); 128 } 129 130 size_t ZHeap::allocated() const { 131 return _page_allocator.allocated(); 132 } 133 134 size_t ZHeap::reclaimed() const { 135 return _page_allocator.reclaimed(); 136 } 137 138 size_t ZHeap::tlab_capacity() const { 139 return capacity(); 140 } 141 142 size_t ZHeap::tlab_used() const { 143 return _object_allocator.used(); 144 } 145 146 size_t ZHeap::max_tlab_size() const { 147 return ZObjectSizeLimitSmall; 148 } 149 150 size_t ZHeap::unsafe_max_tlab_alloc() const { 151 size_t size = _object_allocator.remaining(); 152 153 if (size < MinTLABSize) { 154 // The remaining space in the allocator is not enough to 155 // fit the smallest possible TLAB. This means that the next 156 // TLAB allocation will force the allocator to get a new 157 // backing page anyway, which in turn means that we can then 158 // fit the larges possible TLAB. 159 size = max_tlab_size(); 160 } 161 162 return MIN2(size, max_tlab_size()); 163 } 164 165 bool ZHeap::is_in(uintptr_t addr) const { 166 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) { 167 return false; 168 } 169 170 const ZPage* const page = _pagetable.get(addr); 171 if (page != NULL) { 172 return page->is_in(addr); 173 } 174 175 return false; 176 } 177 178 uintptr_t ZHeap::block_start(uintptr_t addr) const { 179 const ZPage* const page = _pagetable.get(addr); 180 return page->block_start(addr); 181 } 182 183 size_t ZHeap::block_size(uintptr_t addr) const { 184 const ZPage* const page = _pagetable.get(addr); 185 return page->block_size(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 ZPageTableEntry* ZHeap::pagetable_addr() const { 194 return _pagetable.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() { 300 _mark.mark(); 301 } 302 303 void ZHeap::mark_flush_and_free() { 304 _mark.flush_and_free(); 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 and enqueue Soft/Weak/Final/PhantomReferences 372 _reference_processor.process_and_enqueue_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 } 380 381 void ZHeap::destroy_detached_pages() { 382 ZList<ZPage> list; 383 384 _page_allocator.flush_detached_pages(&list); 385 386 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) { 387 // Remove pagetable entry 388 _pagetable.remove(page); 389 390 // Delete the page 391 _page_allocator.destroy_page(page); 392 } 393 } 394 395 void ZHeap::select_relocation_set() { 396 // Register relocatable pages with selector 397 ZRelocationSetSelector selector; 398 ZPageTableIterator iter(&_pagetable); 399 for (ZPage* page; iter.next(&page);) { 400 if (!page->is_relocatable()) { 401 // Not relocatable, don't register 402 continue; 403 } 404 405 if (page->is_marked()) { 406 // Register live page 407 selector.register_live_page(page); 408 } else { 409 // Register garbage page 410 selector.register_garbage_page(page); 411 412 // Reclaim page immediately 413 release_page(page, true /* reclaimed */); 414 } 415 } 416 417 // Select pages to relocate 418 selector.select(&_relocation_set); 419 420 // Update statistics 421 ZStatRelocation::set_at_select_relocation_set(selector.relocating()); 422 ZStatHeap::set_at_select_relocation_set(selector.live(), 423 selector.garbage(), 424 reclaimed()); 425 } 426 427 void ZHeap::prepare_relocation_set() { 428 ZRelocationSetIterator iter(&_relocation_set); 429 for (ZPage* page; iter.next(&page);) { 430 // Prepare for relocation 431 page->set_forwarding(); 432 433 // Update pagetable 434 _pagetable.set_relocating(page); 435 } 436 } 437 438 void ZHeap::reset_relocation_set() { 439 ZRelocationSetIterator iter(&_relocation_set); 440 for (ZPage* page; iter.next(&page);) { 441 // Reset relocation information 442 page->reset_forwarding(); 443 444 // Update pagetable 445 _pagetable.clear_relocating(page); 446 } 447 } 448 449 void ZHeap::relocate_start() { 450 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 451 452 // Update statistics 453 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used()); 454 455 // Flip address view 456 ZAddressMasks::flip_to_remapped(); 457 flip_views(); 458 459 // Remap TLABs 460 _object_allocator.remap_tlabs(); 461 462 // Enter relocate phase 463 ZGlobalPhase = ZPhaseRelocate; 464 465 // Update statistics 466 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used()); 467 468 // Remap/Relocate roots 469 _relocate.start(); 470 } 471 472 uintptr_t ZHeap::relocate_object(uintptr_t addr) { 473 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed"); 474 ZPage* const page = _pagetable.get(addr); 475 const bool retained = retain_page(page); 476 const uintptr_t new_addr = page->relocate_object(addr); 477 if (retained) { 478 release_page(page, true /* reclaimed */); 479 } 480 481 return new_addr; 482 } 483 484 uintptr_t ZHeap::forward_object(uintptr_t addr) { 485 assert(ZGlobalPhase == ZPhaseMark || 486 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed"); 487 ZPage* const page = _pagetable.get(addr); 488 return page->forward_object(addr); 489 } 490 491 void ZHeap::relocate() { 492 // Relocate relocation set 493 const bool success = _relocate.relocate(&_relocation_set); 494 495 // Update statistics 496 ZStatSample(ZSamplerHeapUsedAfterRelocation, used()); 497 ZStatRelocation::set_at_relocate_end(success); 498 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(), 499 used(), used_high(), used_low()); 500 } 501 502 void ZHeap::object_iterate(ObjectClosure* cl) { 503 // Should only be called in a safepoint after mark end. 504 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint"); 505 506 ZHeapIterator iter; 507 iter.objects_do(cl); 508 } 509 510 void ZHeap::serviceability_initialize() { 511 _serviceability.initialize(); 512 } 513 514 GCMemoryManager* ZHeap::serviceability_memory_manager() { 515 return _serviceability.memory_manager(); 516 } 517 518 MemoryPool* ZHeap::serviceability_memory_pool() { 519 return _serviceability.memory_pool(); 520 } 521 522 ZServiceabilityCounters* ZHeap::serviceability_counters() { 523 return _serviceability.counters(); 524 } 525 526 void ZHeap::print_on(outputStream* st) const { 527 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M", 528 used() / M, 529 capacity() / M, 530 max_capacity() / M); 531 MetaspaceAux::print_on(st); 532 } 533 534 void ZHeap::print_extended_on(outputStream* st) const { 535 print_on(st); 536 st->cr(); 537 538 ZPageTableIterator iter(&_pagetable); 539 for (ZPage* page; iter.next(&page);) { 540 page->print_on(st); 541 } 542 543 st->cr(); 544 } 545 546 class ZVerifyRootsTask : public ZTask { 547 private: 548 ZRootsIterator _strong_roots; 549 ZWeakRootsIterator _weak_roots; 550 551 public: 552 ZVerifyRootsTask() : 553 ZTask("ZVerifyRootsTask"), 554 _strong_roots(), 555 _weak_roots() {} 556 557 virtual void work() { 558 ZVerifyRootOopClosure cl; 559 _strong_roots.oops_do(&cl); 560 _weak_roots.oops_do(&cl); 561 } 562 }; 563 564 void ZHeap::verify() { 565 // Heap verification can only be done between mark end and 566 // relocate start. This is the only window where all oop are 567 // good and the whole heap is in a consistent state. 568 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase"); 569 570 { 571 ZVerifyRootsTask task; 572 _workers.run_parallel(&task); 573 } 574 575 { 576 ZVerifyObjectClosure cl; 577 object_iterate(&cl); 578 } 579 }