1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_GC_HEAP_H_ 18 #define ART_RUNTIME_GC_HEAP_H_ 19 20 #include <iosfwd> 21 #include <string> 22 #include <unordered_set> 23 #include <vector> 24 25 #include "allocator_type.h" 26 #include "arch/instruction_set.h" 27 #include "atomic.h" 28 #include "base/time_utils.h" 29 #include "gc/accounting/atomic_stack.h" 30 #include "gc/accounting/card_table.h" 31 #include "gc/accounting/read_barrier_table.h" 32 #include "gc/gc_cause.h" 33 #include "gc/collector/gc_type.h" 34 #include "gc/collector_type.h" 35 #include "gc/space/large_object_space.h" 36 #include "globals.h" 37 #include "handle.h" 38 #include "obj_ptr.h" 39 #include "object_callbacks.h" 40 #include "offsets.h" 41 #include "process_state.h" 42 #include "safe_map.h" 43 #include "verify_object.h" 44 45 namespace art { 46 47 class ConditionVariable; 48 class Mutex; 49 class StackVisitor; 50 class Thread; 51 class ThreadPool; 52 class TimingLogger; 53 class VariableSizedHandleScope; 54 55 namespace mirror { 56 class Class; 57 class Object; 58 } // namespace mirror 59 60 namespace gc { 61 62 class AllocationListener; 63 class AllocRecordObjectMap; 64 class GcPauseListener; 65 class ReferenceProcessor; 66 class TaskProcessor; 67 class Verification; 68 69 namespace accounting { 70 class HeapBitmap; 71 class ModUnionTable; 72 class RememberedSet; 73 } // namespace accounting 74 75 namespace collector { 76 class ConcurrentCopying; 77 class GarbageCollector; 78 class MarkCompact; 79 class MarkSweep; 80 class SemiSpace; 81 } // namespace collector 82 83 namespace allocator { 84 class RosAlloc; 85 } // namespace allocator 86 87 namespace space { 88 class AllocSpace; 89 class BumpPointerSpace; 90 class ContinuousMemMapAllocSpace; 91 class DiscontinuousSpace; 92 class DlMallocSpace; 93 class ImageSpace; 94 class LargeObjectSpace; 95 class MallocSpace; 96 class RegionSpace; 97 class RosAllocSpace; 98 class Space; 99 class ZygoteSpace; 100 } // namespace space 101 102 class AgeCardVisitor { 103 public: 104 uint8_t operator()(uint8_t card) const { 105 return (card == accounting::CardTable::kCardDirty) ? card - 1 : 0; 106 } 107 }; 108 109 enum HomogeneousSpaceCompactResult { 110 // Success. 111 kSuccess, 112 // Reject due to disabled moving GC. 113 kErrorReject, 114 // Unsupported due to the current configuration. 115 kErrorUnsupported, 116 // System is shutting down. 117 kErrorVMShuttingDown, 118 }; 119 120 // If true, use rosalloc/RosAllocSpace instead of dlmalloc/DlMallocSpace 121 static constexpr bool kUseRosAlloc = true; 122 123 // If true, use thread-local allocation stack. 124 static constexpr bool kUseThreadLocalAllocationStack = true; 125 126 class Heap { 127 public: 128 // If true, measure the total allocation time. 129 static constexpr size_t kDefaultStartingSize = kPageSize; 130 static constexpr size_t kDefaultInitialSize = 2 * MB; 131 static constexpr size_t kDefaultMaximumSize = 256 * MB; 132 static constexpr size_t kDefaultNonMovingSpaceCapacity = 64 * MB; 133 static constexpr size_t kDefaultMaxFree = 2 * MB; 134 static constexpr size_t kDefaultMinFree = kDefaultMaxFree / 4; 135 static constexpr size_t kDefaultLongPauseLogThreshold = MsToNs(5); 136 static constexpr size_t kDefaultLongGCLogThreshold = MsToNs(100); 137 static constexpr size_t kDefaultTLABSize = 32 * KB; 138 static constexpr double kDefaultTargetUtilization = 0.5; 139 static constexpr double kDefaultHeapGrowthMultiplier = 2.0; 140 // Primitive arrays larger than this size are put in the large object space. 141 static constexpr size_t kMinLargeObjectThreshold = 3 * kPageSize; 142 static constexpr size_t kDefaultLargeObjectThreshold = kMinLargeObjectThreshold; 143 // Whether or not parallel GC is enabled. If not, then we never create the thread pool. 144 static constexpr bool kDefaultEnableParallelGC = false; 145 146 // Whether or not we use the free list large object space. Only use it if USE_ART_LOW_4G_ALLOCATOR 147 // since this means that we have to use the slow msync loop in MemMap::MapAnonymous. 148 static constexpr space::LargeObjectSpaceType kDefaultLargeObjectSpaceType = 149 USE_ART_LOW_4G_ALLOCATOR ? 150 space::LargeObjectSpaceType::kFreeList 151 : space::LargeObjectSpaceType::kMap; 152 153 // Used so that we don't overflow the allocation time atomic integer. 154 static constexpr size_t kTimeAdjust = 1024; 155 156 // How often we allow heap trimming to happen (nanoseconds). 157 static constexpr uint64_t kHeapTrimWait = MsToNs(5000); 158 // How long we wait after a transition request to perform a collector transition (nanoseconds). 159 static constexpr uint64_t kCollectorTransitionWait = MsToNs(5000); 160 161 // Create a heap with the requested sizes. The possible empty 162 // image_file_names names specify Spaces to load based on 163 // ImageWriter output. 164 Heap(size_t initial_size, 165 size_t growth_limit, 166 size_t min_free, 167 size_t max_free, 168 double target_utilization, 169 double foreground_heap_growth_multiplier, 170 size_t capacity, 171 size_t non_moving_space_capacity, 172 const std::string& original_image_file_name, 173 InstructionSet image_instruction_set, 174 CollectorType foreground_collector_type, 175 CollectorType background_collector_type, 176 space::LargeObjectSpaceType large_object_space_type, 177 size_t large_object_threshold, 178 size_t parallel_gc_threads, 179 size_t conc_gc_threads, 180 bool low_memory_mode, 181 size_t long_pause_threshold, 182 size_t long_gc_threshold, 183 bool ignore_max_footprint, 184 bool use_tlab, 185 bool verify_pre_gc_heap, 186 bool verify_pre_sweeping_heap, 187 bool verify_post_gc_heap, 188 bool verify_pre_gc_rosalloc, 189 bool verify_pre_sweeping_rosalloc, 190 bool verify_post_gc_rosalloc, 191 bool gc_stress_mode, 192 bool measure_gc_performance, 193 bool use_homogeneous_space_compaction, 194 uint64_t min_interval_homogeneous_space_compaction_by_oom); 195 196 ~Heap(); 197 198 // Allocates and initializes storage for an object instance. 199 template <bool kInstrumented, typename PreFenceVisitor> 200 mirror::Object* AllocObject(Thread* self, 201 ObjPtr<mirror::Class> klass, 202 size_t num_bytes, 203 const PreFenceVisitor& pre_fence_visitor) 204 REQUIRES_SHARED(Locks::mutator_lock_) 205 REQUIRES(!*gc_complete_lock_, 206 !*pending_task_lock_, 207 !*backtrace_lock_, 208 !Roles::uninterruptible_) { 209 return AllocObjectWithAllocator<kInstrumented, true>(self, 210 klass, 211 num_bytes, 212 GetCurrentAllocator(), 213 pre_fence_visitor); 214 } 215 216 template <bool kInstrumented, typename PreFenceVisitor> 217 mirror::Object* AllocNonMovableObject(Thread* self, 218 ObjPtr<mirror::Class> klass, 219 size_t num_bytes, 220 const PreFenceVisitor& pre_fence_visitor) 221 REQUIRES_SHARED(Locks::mutator_lock_) 222 REQUIRES(!*gc_complete_lock_, 223 !*pending_task_lock_, 224 !*backtrace_lock_, 225 !Roles::uninterruptible_) { 226 return AllocObjectWithAllocator<kInstrumented, true>(self, 227 klass, 228 num_bytes, 229 GetCurrentNonMovingAllocator(), 230 pre_fence_visitor); 231 } 232 233 template <bool kInstrumented, bool kCheckLargeObject, typename PreFenceVisitor> 234 ALWAYS_INLINE mirror::Object* AllocObjectWithAllocator(Thread* self, 235 ObjPtr<mirror::Class> klass, 236 size_t byte_count, 237 AllocatorType allocator, 238 const PreFenceVisitor& pre_fence_visitor) 239 REQUIRES_SHARED(Locks::mutator_lock_) 240 REQUIRES(!*gc_complete_lock_, 241 !*pending_task_lock_, 242 !*backtrace_lock_, 243 !Roles::uninterruptible_); 244 245 AllocatorType GetCurrentAllocator() const { 246 return current_allocator_; 247 } 248 249 AllocatorType GetCurrentNonMovingAllocator() const { 250 return current_non_moving_allocator_; 251 } 252 253 // Visit all of the live objects in the heap. 254 void VisitObjects(ObjectCallback callback, void* arg) 255 REQUIRES_SHARED(Locks::mutator_lock_) 256 REQUIRES(!Locks::heap_bitmap_lock_, !*gc_complete_lock_); 257 void VisitObjectsPaused(ObjectCallback callback, void* arg) 258 REQUIRES(Locks::mutator_lock_, !Locks::heap_bitmap_lock_, !*gc_complete_lock_); 259 260 void CheckPreconditionsForAllocObject(ObjPtr<mirror::Class> c, size_t byte_count) 261 REQUIRES_SHARED(Locks::mutator_lock_); 262 263 void RegisterNativeAllocation(JNIEnv* env, size_t bytes) 264 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_, !*native_blocking_gc_lock_); 265 void RegisterNativeFree(JNIEnv* env, size_t bytes); 266 267 // Change the allocator, updates entrypoints. 268 void ChangeAllocator(AllocatorType allocator) 269 REQUIRES(Locks::mutator_lock_, !Locks::runtime_shutdown_lock_); 270 271 // Transition the garbage collector during runtime, may copy objects from one space to another. 272 void TransitionCollector(CollectorType collector_type) REQUIRES(!*gc_complete_lock_); 273 274 // Change the collector to be one of the possible options (MS, CMS, SS). 275 void ChangeCollector(CollectorType collector_type) 276 REQUIRES(Locks::mutator_lock_); 277 278 // The given reference is believed to be to an object in the Java heap, check the soundness of it. 279 // TODO: NO_THREAD_SAFETY_ANALYSIS since we call this everywhere and it is impossible to find a 280 // proper lock ordering for it. 281 void VerifyObjectBody(ObjPtr<mirror::Object> o) NO_THREAD_SAFETY_ANALYSIS; 282 283 // Check sanity of all live references. 284 void VerifyHeap() REQUIRES(!Locks::heap_bitmap_lock_); 285 // Returns how many failures occured. 286 size_t VerifyHeapReferences(bool verify_referents = true) 287 REQUIRES(Locks::mutator_lock_, !*gc_complete_lock_); 288 bool VerifyMissingCardMarks() 289 REQUIRES(Locks::heap_bitmap_lock_, Locks::mutator_lock_); 290 291 // A weaker test than IsLiveObject or VerifyObject that doesn't require the heap lock, 292 // and doesn't abort on error, allowing the caller to report more 293 // meaningful diagnostics. 294 bool IsValidObjectAddress(const void* obj) const REQUIRES_SHARED(Locks::mutator_lock_); 295 296 // Faster alternative to IsHeapAddress since finding if an object is in the large object space is 297 // very slow. 298 bool IsNonDiscontinuousSpaceHeapAddress(const void* addr) const 299 REQUIRES_SHARED(Locks::mutator_lock_); 300 301 // Returns true if 'obj' is a live heap object, false otherwise (including for invalid addresses). 302 // Requires the heap lock to be held. 303 bool IsLiveObjectLocked(ObjPtr<mirror::Object> obj, 304 bool search_allocation_stack = true, 305 bool search_live_stack = true, 306 bool sorted = false) 307 REQUIRES_SHARED(Locks::heap_bitmap_lock_, Locks::mutator_lock_); 308 309 // Returns true if there is any chance that the object (obj) will move. 310 bool IsMovableObject(ObjPtr<mirror::Object> obj) const REQUIRES_SHARED(Locks::mutator_lock_); 311 312 // Enables us to compacting GC until objects are released. 313 void IncrementDisableMovingGC(Thread* self) REQUIRES(!*gc_complete_lock_); 314 void DecrementDisableMovingGC(Thread* self) REQUIRES(!*gc_complete_lock_); 315 316 // Temporarily disable thread flip for JNI critical calls. 317 void IncrementDisableThreadFlip(Thread* self) REQUIRES(!*thread_flip_lock_); 318 void DecrementDisableThreadFlip(Thread* self) REQUIRES(!*thread_flip_lock_); 319 void ThreadFlipBegin(Thread* self) REQUIRES(!*thread_flip_lock_); 320 void ThreadFlipEnd(Thread* self) REQUIRES(!*thread_flip_lock_); 321 322 // Clear all of the mark bits, doesn't clear bitmaps which have the same live bits as mark bits. 323 // Mutator lock is required for GetContinuousSpaces. 324 void ClearMarkedObjects() 325 REQUIRES(Locks::heap_bitmap_lock_) 326 REQUIRES_SHARED(Locks::mutator_lock_); 327 328 // Initiates an explicit garbage collection. 329 void CollectGarbage(bool clear_soft_references) 330 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_); 331 332 // Does a concurrent GC, should only be called by the GC daemon thread 333 // through runtime. 334 void ConcurrentGC(Thread* self, GcCause cause, bool force_full) 335 REQUIRES(!Locks::runtime_shutdown_lock_, !*gc_complete_lock_, !*pending_task_lock_); 336 337 // Implements VMDebug.countInstancesOfClass and JDWP VM_InstanceCount. 338 // The boolean decides whether to use IsAssignableFrom or == when comparing classes. 339 void CountInstances(const std::vector<Handle<mirror::Class>>& classes, 340 bool use_is_assignable_from, 341 uint64_t* counts) 342 REQUIRES(!Locks::heap_bitmap_lock_, !*gc_complete_lock_) 343 REQUIRES_SHARED(Locks::mutator_lock_); 344 345 // Implements JDWP RT_Instances. 346 void GetInstances(VariableSizedHandleScope& scope, 347 Handle<mirror::Class> c, 348 int32_t max_count, 349 std::vector<Handle<mirror::Object>>& instances) 350 REQUIRES(!Locks::heap_bitmap_lock_, !*gc_complete_lock_) 351 REQUIRES_SHARED(Locks::mutator_lock_); 352 353 // Implements JDWP OR_ReferringObjects. 354 void GetReferringObjects(VariableSizedHandleScope& scope, 355 Handle<mirror::Object> o, 356 int32_t max_count, 357 std::vector<Handle<mirror::Object>>& referring_objects) 358 REQUIRES(!Locks::heap_bitmap_lock_, !*gc_complete_lock_) 359 REQUIRES_SHARED(Locks::mutator_lock_); 360 361 // Removes the growth limit on the alloc space so it may grow to its maximum capacity. Used to 362 // implement dalvik.system.VMRuntime.clearGrowthLimit. 363 void ClearGrowthLimit(); 364 365 // Make the current growth limit the new maximum capacity, unmaps pages at the end of spaces 366 // which will never be used. Used to implement dalvik.system.VMRuntime.clampGrowthLimit. 367 void ClampGrowthLimit() REQUIRES(!Locks::heap_bitmap_lock_); 368 369 // Target ideal heap utilization ratio, implements 370 // dalvik.system.VMRuntime.getTargetHeapUtilization. 371 double GetTargetHeapUtilization() const { 372 return target_utilization_; 373 } 374 375 // Data structure memory usage tracking. 376 void RegisterGCAllocation(size_t bytes); 377 void RegisterGCDeAllocation(size_t bytes); 378 379 // Set the heap's private space pointers to be the same as the space based on it's type. Public 380 // due to usage by tests. 381 void SetSpaceAsDefault(space::ContinuousSpace* continuous_space) 382 REQUIRES(!Locks::heap_bitmap_lock_); 383 void AddSpace(space::Space* space) 384 REQUIRES(!Locks::heap_bitmap_lock_) 385 REQUIRES(Locks::mutator_lock_); 386 void RemoveSpace(space::Space* space) 387 REQUIRES(!Locks::heap_bitmap_lock_) 388 REQUIRES(Locks::mutator_lock_); 389 390 // Set target ideal heap utilization ratio, implements 391 // dalvik.system.VMRuntime.setTargetHeapUtilization. 392 void SetTargetHeapUtilization(float target); 393 394 // For the alloc space, sets the maximum number of bytes that the heap is allowed to allocate 395 // from the system. Doesn't allow the space to exceed its growth limit. 396 void SetIdealFootprint(size_t max_allowed_footprint); 397 398 // Blocks the caller until the garbage collector becomes idle and returns the type of GC we 399 // waited for. 400 collector::GcType WaitForGcToComplete(GcCause cause, Thread* self) REQUIRES(!*gc_complete_lock_); 401 402 // Update the heap's process state to a new value, may cause compaction to occur. 403 void UpdateProcessState(ProcessState old_process_state, ProcessState new_process_state) 404 REQUIRES(!*pending_task_lock_, !*gc_complete_lock_); 405 406 bool HaveContinuousSpaces() const NO_THREAD_SAFETY_ANALYSIS { 407 // No lock since vector empty is thread safe. 408 return !continuous_spaces_.empty(); 409 } 410 411 const std::vector<space::ContinuousSpace*>& GetContinuousSpaces() const 412 REQUIRES_SHARED(Locks::mutator_lock_) { 413 return continuous_spaces_; 414 } 415 416 const std::vector<space::DiscontinuousSpace*>& GetDiscontinuousSpaces() const { 417 return discontinuous_spaces_; 418 } 419 420 const collector::Iteration* GetCurrentGcIteration() const { 421 return ¤t_gc_iteration_; 422 } 423 collector::Iteration* GetCurrentGcIteration() { 424 return ¤t_gc_iteration_; 425 } 426 427 // Enable verification of object references when the runtime is sufficiently initialized. 428 void EnableObjectValidation() { 429 verify_object_mode_ = kVerifyObjectSupport; 430 if (verify_object_mode_ > kVerifyObjectModeDisabled) { 431 VerifyHeap(); 432 } 433 } 434 435 // Disable object reference verification for image writing. 436 void DisableObjectValidation() { 437 verify_object_mode_ = kVerifyObjectModeDisabled; 438 } 439 440 // Other checks may be performed if we know the heap should be in a sane state. 441 bool IsObjectValidationEnabled() const { 442 return verify_object_mode_ > kVerifyObjectModeDisabled; 443 } 444 445 // Returns true if low memory mode is enabled. 446 bool IsLowMemoryMode() const { 447 return low_memory_mode_; 448 } 449 450 // Returns the heap growth multiplier, this affects how much we grow the heap after a GC. 451 // Scales heap growth, min free, and max free. 452 double HeapGrowthMultiplier() const; 453 454 // Freed bytes can be negative in cases where we copy objects from a compacted space to a 455 // free-list backed space. 456 void RecordFree(uint64_t freed_objects, int64_t freed_bytes); 457 458 // Record the bytes freed by thread-local buffer revoke. 459 void RecordFreeRevoke(); 460 461 // Must be called if a field of an Object in the heap changes, and before any GC safe-point. 462 // The call is not needed if null is stored in the field. 463 ALWAYS_INLINE void WriteBarrierField(ObjPtr<mirror::Object> dst, 464 MemberOffset offset, 465 ObjPtr<mirror::Object> new_value) 466 REQUIRES_SHARED(Locks::mutator_lock_); 467 468 // Write barrier for array operations that update many field positions 469 ALWAYS_INLINE void WriteBarrierArray(ObjPtr<mirror::Object> dst, 470 int start_offset, 471 // TODO: element_count or byte_count? 472 size_t length) 473 REQUIRES_SHARED(Locks::mutator_lock_); 474 475 ALWAYS_INLINE void WriteBarrierEveryFieldOf(ObjPtr<mirror::Object> obj) 476 REQUIRES_SHARED(Locks::mutator_lock_); 477 478 accounting::CardTable* GetCardTable() const { 479 return card_table_.get(); 480 } 481 482 accounting::ReadBarrierTable* GetReadBarrierTable() const { 483 return rb_table_.get(); 484 } 485 486 void AddFinalizerReference(Thread* self, ObjPtr<mirror::Object>* object); 487 488 // Returns the number of bytes currently allocated. 489 size_t GetBytesAllocated() const { 490 return num_bytes_allocated_.LoadSequentiallyConsistent(); 491 } 492 493 // Returns the number of objects currently allocated. 494 size_t GetObjectsAllocated() const 495 REQUIRES(!Locks::heap_bitmap_lock_); 496 497 // Returns the total number of objects allocated since the heap was created. 498 uint64_t GetObjectsAllocatedEver() const; 499 500 // Returns the total number of bytes allocated since the heap was created. 501 uint64_t GetBytesAllocatedEver() const; 502 503 // Returns the total number of objects freed since the heap was created. 504 uint64_t GetObjectsFreedEver() const { 505 return total_objects_freed_ever_; 506 } 507 508 // Returns the total number of bytes freed since the heap was created. 509 uint64_t GetBytesFreedEver() const { 510 return total_bytes_freed_ever_; 511 } 512 513 // Implements java.lang.Runtime.maxMemory, returning the maximum amount of memory a program can 514 // consume. For a regular VM this would relate to the -Xmx option and would return -1 if no Xmx 515 // were specified. Android apps start with a growth limit (small heap size) which is 516 // cleared/extended for large apps. 517 size_t GetMaxMemory() const { 518 // There is some race conditions in the allocation code that can cause bytes allocated to 519 // become larger than growth_limit_ in rare cases. 520 return std::max(GetBytesAllocated(), growth_limit_); 521 } 522 523 // Implements java.lang.Runtime.totalMemory, returning approximate amount of memory currently 524 // consumed by an application. 525 size_t GetTotalMemory() const; 526 527 // Returns approximately how much free memory we have until the next GC happens. 528 size_t GetFreeMemoryUntilGC() const { 529 return max_allowed_footprint_ - GetBytesAllocated(); 530 } 531 532 // Returns approximately how much free memory we have until the next OOME happens. 533 size_t GetFreeMemoryUntilOOME() const { 534 return growth_limit_ - GetBytesAllocated(); 535 } 536 537 // Returns how much free memory we have until we need to grow the heap to perform an allocation. 538 // Similar to GetFreeMemoryUntilGC. Implements java.lang.Runtime.freeMemory. 539 size_t GetFreeMemory() const { 540 size_t byte_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 541 size_t total_memory = GetTotalMemory(); 542 // Make sure we don't get a negative number. 543 return total_memory - std::min(total_memory, byte_allocated); 544 } 545 546 // get the space that corresponds to an object's address. Current implementation searches all 547 // spaces in turn. If fail_ok is false then failing to find a space will cause an abort. 548 // TODO: consider using faster data structure like binary tree. 549 space::ContinuousSpace* FindContinuousSpaceFromObject(ObjPtr<mirror::Object>, bool fail_ok) const 550 REQUIRES_SHARED(Locks::mutator_lock_); 551 552 space::ContinuousSpace* FindContinuousSpaceFromAddress(const mirror::Object* addr) const 553 REQUIRES_SHARED(Locks::mutator_lock_); 554 555 space::DiscontinuousSpace* FindDiscontinuousSpaceFromObject(ObjPtr<mirror::Object>, 556 bool fail_ok) const 557 REQUIRES_SHARED(Locks::mutator_lock_); 558 559 space::Space* FindSpaceFromObject(ObjPtr<mirror::Object> obj, bool fail_ok) const 560 REQUIRES_SHARED(Locks::mutator_lock_); 561 562 space::Space* FindSpaceFromAddress(const void* ptr) const 563 REQUIRES_SHARED(Locks::mutator_lock_); 564 565 void DumpForSigQuit(std::ostream& os) REQUIRES(!*gc_complete_lock_); 566 567 // Do a pending collector transition. 568 void DoPendingCollectorTransition() REQUIRES(!*gc_complete_lock_, !*pending_task_lock_); 569 570 // Deflate monitors, ... and trim the spaces. 571 void Trim(Thread* self) REQUIRES(!*gc_complete_lock_); 572 573 void RevokeThreadLocalBuffers(Thread* thread); 574 void RevokeRosAllocThreadLocalBuffers(Thread* thread); 575 void RevokeAllThreadLocalBuffers(); 576 void AssertThreadLocalBuffersAreRevoked(Thread* thread); 577 void AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked(); 578 void RosAllocVerification(TimingLogger* timings, const char* name) 579 REQUIRES(Locks::mutator_lock_); 580 581 accounting::HeapBitmap* GetLiveBitmap() REQUIRES_SHARED(Locks::heap_bitmap_lock_) { 582 return live_bitmap_.get(); 583 } 584 585 accounting::HeapBitmap* GetMarkBitmap() REQUIRES_SHARED(Locks::heap_bitmap_lock_) { 586 return mark_bitmap_.get(); 587 } 588 589 accounting::ObjectStack* GetLiveStack() REQUIRES_SHARED(Locks::heap_bitmap_lock_) { 590 return live_stack_.get(); 591 } 592 593 void PreZygoteFork() NO_THREAD_SAFETY_ANALYSIS; 594 595 // Mark and empty stack. 596 void FlushAllocStack() 597 REQUIRES_SHARED(Locks::mutator_lock_) 598 REQUIRES(Locks::heap_bitmap_lock_); 599 600 // Revoke all the thread-local allocation stacks. 601 void RevokeAllThreadLocalAllocationStacks(Thread* self) 602 REQUIRES(Locks::mutator_lock_, !Locks::runtime_shutdown_lock_, !Locks::thread_list_lock_); 603 604 // Mark all the objects in the allocation stack in the specified bitmap. 605 // TODO: Refactor? 606 void MarkAllocStack(accounting::SpaceBitmap<kObjectAlignment>* bitmap1, 607 accounting::SpaceBitmap<kObjectAlignment>* bitmap2, 608 accounting::SpaceBitmap<kLargeObjectAlignment>* large_objects, 609 accounting::ObjectStack* stack) 610 REQUIRES_SHARED(Locks::mutator_lock_) 611 REQUIRES(Locks::heap_bitmap_lock_); 612 613 // Mark the specified allocation stack as live. 614 void MarkAllocStackAsLive(accounting::ObjectStack* stack) 615 REQUIRES_SHARED(Locks::mutator_lock_) 616 REQUIRES(Locks::heap_bitmap_lock_); 617 618 // Unbind any bound bitmaps. 619 void UnBindBitmaps() 620 REQUIRES(Locks::heap_bitmap_lock_) 621 REQUIRES_SHARED(Locks::mutator_lock_); 622 623 // Returns the boot image spaces. There may be multiple boot image spaces. 624 const std::vector<space::ImageSpace*>& GetBootImageSpaces() const { 625 return boot_image_spaces_; 626 } 627 628 bool ObjectIsInBootImageSpace(ObjPtr<mirror::Object> obj) const 629 REQUIRES_SHARED(Locks::mutator_lock_); 630 631 bool IsInBootImageOatFile(const void* p) const 632 REQUIRES_SHARED(Locks::mutator_lock_); 633 634 void GetBootImagesSize(uint32_t* boot_image_begin, 635 uint32_t* boot_image_end, 636 uint32_t* boot_oat_begin, 637 uint32_t* boot_oat_end); 638 639 // Permenantly disable moving garbage collection. 640 void DisableMovingGc() REQUIRES(!*gc_complete_lock_); 641 642 space::DlMallocSpace* GetDlMallocSpace() const { 643 return dlmalloc_space_; 644 } 645 646 space::RosAllocSpace* GetRosAllocSpace() const { 647 return rosalloc_space_; 648 } 649 650 // Return the corresponding rosalloc space. 651 space::RosAllocSpace* GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const 652 REQUIRES_SHARED(Locks::mutator_lock_); 653 654 space::MallocSpace* GetNonMovingSpace() const { 655 return non_moving_space_; 656 } 657 658 space::LargeObjectSpace* GetLargeObjectsSpace() const { 659 return large_object_space_; 660 } 661 662 // Returns the free list space that may contain movable objects (the 663 // one that's not the non-moving space), either rosalloc_space_ or 664 // dlmalloc_space_. 665 space::MallocSpace* GetPrimaryFreeListSpace() { 666 if (kUseRosAlloc) { 667 DCHECK(rosalloc_space_ != nullptr); 668 // reinterpret_cast is necessary as the space class hierarchy 669 // isn't known (#included) yet here. 670 return reinterpret_cast<space::MallocSpace*>(rosalloc_space_); 671 } else { 672 DCHECK(dlmalloc_space_ != nullptr); 673 return reinterpret_cast<space::MallocSpace*>(dlmalloc_space_); 674 } 675 } 676 677 void DumpSpaces(std::ostream& stream) const REQUIRES_SHARED(Locks::mutator_lock_); 678 std::string DumpSpaces() const REQUIRES_SHARED(Locks::mutator_lock_); 679 680 // GC performance measuring 681 void DumpGcPerformanceInfo(std::ostream& os) 682 REQUIRES(!*gc_complete_lock_); 683 void ResetGcPerformanceInfo() REQUIRES(!*gc_complete_lock_); 684 685 // Thread pool. 686 void CreateThreadPool(); 687 void DeleteThreadPool(); 688 ThreadPool* GetThreadPool() { 689 return thread_pool_.get(); 690 } 691 size_t GetParallelGCThreadCount() const { 692 return parallel_gc_threads_; 693 } 694 size_t GetConcGCThreadCount() const { 695 return conc_gc_threads_; 696 } 697 accounting::ModUnionTable* FindModUnionTableFromSpace(space::Space* space); 698 void AddModUnionTable(accounting::ModUnionTable* mod_union_table); 699 700 accounting::RememberedSet* FindRememberedSetFromSpace(space::Space* space); 701 void AddRememberedSet(accounting::RememberedSet* remembered_set); 702 // Also deletes the remebered set. 703 void RemoveRememberedSet(space::Space* space); 704 705 bool IsCompilingBoot() const; 706 bool HasBootImageSpace() const { 707 return !boot_image_spaces_.empty(); 708 } 709 710 ReferenceProcessor* GetReferenceProcessor() { 711 return reference_processor_.get(); 712 } 713 TaskProcessor* GetTaskProcessor() { 714 return task_processor_.get(); 715 } 716 717 bool HasZygoteSpace() const { 718 return zygote_space_ != nullptr; 719 } 720 721 collector::ConcurrentCopying* ConcurrentCopyingCollector() { 722 return concurrent_copying_collector_; 723 } 724 725 CollectorType CurrentCollectorType() { 726 return collector_type_; 727 } 728 729 bool IsGcConcurrentAndMoving() const { 730 if (IsGcConcurrent() && IsMovingGc(collector_type_)) { 731 // Assume no transition when a concurrent moving collector is used. 732 DCHECK_EQ(collector_type_, foreground_collector_type_); 733 return true; 734 } 735 return false; 736 } 737 738 bool IsMovingGCDisabled(Thread* self) REQUIRES(!*gc_complete_lock_) { 739 MutexLock mu(self, *gc_complete_lock_); 740 return disable_moving_gc_count_ > 0; 741 } 742 743 // Request an asynchronous trim. 744 void RequestTrim(Thread* self) REQUIRES(!*pending_task_lock_); 745 746 // Request asynchronous GC. 747 void RequestConcurrentGC(Thread* self, GcCause cause, bool force_full) 748 REQUIRES(!*pending_task_lock_); 749 750 // Whether or not we may use a garbage collector, used so that we only create collectors we need. 751 bool MayUseCollector(CollectorType type) const; 752 753 // Used by tests to reduce timinig-dependent flakiness in OOME behavior. 754 void SetMinIntervalHomogeneousSpaceCompactionByOom(uint64_t interval) { 755 min_interval_homogeneous_space_compaction_by_oom_ = interval; 756 } 757 758 // Helpers for android.os.Debug.getRuntimeStat(). 759 uint64_t GetGcCount() const; 760 uint64_t GetGcTime() const; 761 uint64_t GetBlockingGcCount() const; 762 uint64_t GetBlockingGcTime() const; 763 void DumpGcCountRateHistogram(std::ostream& os) const REQUIRES(!*gc_complete_lock_); 764 void DumpBlockingGcCountRateHistogram(std::ostream& os) const REQUIRES(!*gc_complete_lock_); 765 766 // Allocation tracking support 767 // Callers to this function use double-checked locking to ensure safety on allocation_records_ 768 bool IsAllocTrackingEnabled() const { 769 return alloc_tracking_enabled_.LoadRelaxed(); 770 } 771 772 void SetAllocTrackingEnabled(bool enabled) REQUIRES(Locks::alloc_tracker_lock_) { 773 alloc_tracking_enabled_.StoreRelaxed(enabled); 774 } 775 776 AllocRecordObjectMap* GetAllocationRecords() const 777 REQUIRES(Locks::alloc_tracker_lock_) { 778 return allocation_records_.get(); 779 } 780 781 void SetAllocationRecords(AllocRecordObjectMap* records) 782 REQUIRES(Locks::alloc_tracker_lock_); 783 784 void VisitAllocationRecords(RootVisitor* visitor) const 785 REQUIRES_SHARED(Locks::mutator_lock_) 786 REQUIRES(!Locks::alloc_tracker_lock_); 787 788 void SweepAllocationRecords(IsMarkedVisitor* visitor) const 789 REQUIRES_SHARED(Locks::mutator_lock_) 790 REQUIRES(!Locks::alloc_tracker_lock_); 791 792 void DisallowNewAllocationRecords() const 793 REQUIRES_SHARED(Locks::mutator_lock_) 794 REQUIRES(!Locks::alloc_tracker_lock_); 795 796 void AllowNewAllocationRecords() const 797 REQUIRES_SHARED(Locks::mutator_lock_) 798 REQUIRES(!Locks::alloc_tracker_lock_); 799 800 void BroadcastForNewAllocationRecords() const 801 REQUIRES(!Locks::alloc_tracker_lock_); 802 803 void DisableGCForShutdown() REQUIRES(!*gc_complete_lock_); 804 805 // Create a new alloc space and compact default alloc space to it. 806 HomogeneousSpaceCompactResult PerformHomogeneousSpaceCompact() REQUIRES(!*gc_complete_lock_); 807 bool SupportHomogeneousSpaceCompactAndCollectorTransitions() const; 808 809 // Install an allocation listener. 810 void SetAllocationListener(AllocationListener* l); 811 // Remove an allocation listener. Note: the listener must not be deleted, as for performance 812 // reasons, we assume it stays valid when we read it (so that we don't require a lock). 813 void RemoveAllocationListener(); 814 815 // Install a gc pause listener. 816 void SetGcPauseListener(GcPauseListener* l); 817 // Get the currently installed gc pause listener, or null. 818 GcPauseListener* GetGcPauseListener() { 819 return gc_pause_listener_.LoadAcquire(); 820 } 821 // Remove a gc pause listener. Note: the listener must not be deleted, as for performance 822 // reasons, we assume it stays valid when we read it (so that we don't require a lock). 823 void RemoveGcPauseListener(); 824 825 const Verification* GetVerification() const; 826 827 private: 828 class ConcurrentGCTask; 829 class CollectorTransitionTask; 830 class HeapTrimTask; 831 832 // Compact source space to target space. Returns the collector used. 833 collector::GarbageCollector* Compact(space::ContinuousMemMapAllocSpace* target_space, 834 space::ContinuousMemMapAllocSpace* source_space, 835 GcCause gc_cause) 836 REQUIRES(Locks::mutator_lock_); 837 838 void LogGC(GcCause gc_cause, collector::GarbageCollector* collector); 839 void StartGC(Thread* self, GcCause cause, CollectorType collector_type) 840 REQUIRES(!*gc_complete_lock_); 841 void FinishGC(Thread* self, collector::GcType gc_type) REQUIRES(!*gc_complete_lock_); 842 843 // Create a mem map with a preferred base address. 844 static MemMap* MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 845 size_t capacity, std::string* out_error_str); 846 847 bool SupportHSpaceCompaction() const { 848 // Returns true if we can do hspace compaction 849 return main_space_backup_ != nullptr; 850 } 851 852 static ALWAYS_INLINE bool AllocatorHasAllocationStack(AllocatorType allocator_type) { 853 return 854 allocator_type != kAllocatorTypeBumpPointer && 855 allocator_type != kAllocatorTypeTLAB && 856 allocator_type != kAllocatorTypeRegion && 857 allocator_type != kAllocatorTypeRegionTLAB; 858 } 859 static ALWAYS_INLINE bool AllocatorMayHaveConcurrentGC(AllocatorType allocator_type) { 860 if (kUseReadBarrier) { 861 // Read barrier may have the TLAB allocator but is always concurrent. TODO: clean this up. 862 return true; 863 } 864 return 865 allocator_type != kAllocatorTypeBumpPointer && 866 allocator_type != kAllocatorTypeTLAB; 867 } 868 static bool IsMovingGc(CollectorType collector_type) { 869 return 870 collector_type == kCollectorTypeSS || 871 collector_type == kCollectorTypeGSS || 872 collector_type == kCollectorTypeCC || 873 collector_type == kCollectorTypeCCBackground || 874 collector_type == kCollectorTypeMC || 875 collector_type == kCollectorTypeHomogeneousSpaceCompact; 876 } 877 bool ShouldAllocLargeObject(ObjPtr<mirror::Class> c, size_t byte_count) const 878 REQUIRES_SHARED(Locks::mutator_lock_); 879 ALWAYS_INLINE void CheckConcurrentGC(Thread* self, 880 size_t new_num_bytes_allocated, 881 ObjPtr<mirror::Object>* obj) 882 REQUIRES_SHARED(Locks::mutator_lock_) 883 REQUIRES(!*pending_task_lock_, !*gc_complete_lock_); 884 885 accounting::ObjectStack* GetMarkStack() { 886 return mark_stack_.get(); 887 } 888 889 // We don't force this to be inlined since it is a slow path. 890 template <bool kInstrumented, typename PreFenceVisitor> 891 mirror::Object* AllocLargeObject(Thread* self, 892 ObjPtr<mirror::Class>* klass, 893 size_t byte_count, 894 const PreFenceVisitor& pre_fence_visitor) 895 REQUIRES_SHARED(Locks::mutator_lock_) 896 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_, !*backtrace_lock_); 897 898 // Handles Allocate()'s slow allocation path with GC involved after 899 // an initial allocation attempt failed. 900 mirror::Object* AllocateInternalWithGc(Thread* self, 901 AllocatorType allocator, 902 bool instrumented, 903 size_t num_bytes, 904 size_t* bytes_allocated, 905 size_t* usable_size, 906 size_t* bytes_tl_bulk_allocated, 907 ObjPtr<mirror::Class>* klass) 908 REQUIRES(!Locks::thread_suspend_count_lock_, !*gc_complete_lock_, !*pending_task_lock_) 909 REQUIRES_SHARED(Locks::mutator_lock_); 910 911 // Allocate into a specific space. 912 mirror::Object* AllocateInto(Thread* self, 913 space::AllocSpace* space, 914 ObjPtr<mirror::Class> c, 915 size_t bytes) 916 REQUIRES_SHARED(Locks::mutator_lock_); 917 918 // Need to do this with mutators paused so that somebody doesn't accidentally allocate into the 919 // wrong space. 920 void SwapSemiSpaces() REQUIRES(Locks::mutator_lock_); 921 922 // Try to allocate a number of bytes, this function never does any GCs. Needs to be inlined so 923 // that the switch statement is constant optimized in the entrypoints. 924 template <const bool kInstrumented, const bool kGrow> 925 ALWAYS_INLINE mirror::Object* TryToAllocate(Thread* self, 926 AllocatorType allocator_type, 927 size_t alloc_size, 928 size_t* bytes_allocated, 929 size_t* usable_size, 930 size_t* bytes_tl_bulk_allocated) 931 REQUIRES_SHARED(Locks::mutator_lock_); 932 933 mirror::Object* AllocWithNewTLAB(Thread* self, 934 size_t alloc_size, 935 bool grow, 936 size_t* bytes_allocated, 937 size_t* usable_size, 938 size_t* bytes_tl_bulk_allocated) 939 REQUIRES_SHARED(Locks::mutator_lock_); 940 941 void ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) 942 REQUIRES_SHARED(Locks::mutator_lock_); 943 944 ALWAYS_INLINE bool IsOutOfMemoryOnAllocation(AllocatorType allocator_type, 945 size_t alloc_size, 946 bool grow); 947 948 // Run the finalizers. If timeout is non zero, then we use the VMRuntime version. 949 void RunFinalization(JNIEnv* env, uint64_t timeout); 950 951 // Blocks the caller until the garbage collector becomes idle and returns the type of GC we 952 // waited for. 953 collector::GcType WaitForGcToCompleteLocked(GcCause cause, Thread* self) 954 REQUIRES(gc_complete_lock_); 955 956 void RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) 957 REQUIRES(!*pending_task_lock_); 958 959 void RequestConcurrentGCAndSaveObject(Thread* self, bool force_full, ObjPtr<mirror::Object>* obj) 960 REQUIRES_SHARED(Locks::mutator_lock_) 961 REQUIRES(!*pending_task_lock_); 962 bool IsGCRequestPending() const; 963 964 // Sometimes CollectGarbageInternal decides to run a different Gc than you requested. Returns 965 // which type of Gc was actually ran. 966 collector::GcType CollectGarbageInternal(collector::GcType gc_plan, 967 GcCause gc_cause, 968 bool clear_soft_references) 969 REQUIRES(!*gc_complete_lock_, !Locks::heap_bitmap_lock_, !Locks::thread_suspend_count_lock_, 970 !*pending_task_lock_); 971 972 void PreGcVerification(collector::GarbageCollector* gc) 973 REQUIRES(!Locks::mutator_lock_, !*gc_complete_lock_); 974 void PreGcVerificationPaused(collector::GarbageCollector* gc) 975 REQUIRES(Locks::mutator_lock_, !*gc_complete_lock_); 976 void PrePauseRosAllocVerification(collector::GarbageCollector* gc) 977 REQUIRES(Locks::mutator_lock_); 978 void PreSweepingGcVerification(collector::GarbageCollector* gc) 979 REQUIRES(Locks::mutator_lock_, !Locks::heap_bitmap_lock_, !*gc_complete_lock_); 980 void PostGcVerification(collector::GarbageCollector* gc) 981 REQUIRES(!Locks::mutator_lock_, !*gc_complete_lock_); 982 void PostGcVerificationPaused(collector::GarbageCollector* gc) 983 REQUIRES(Locks::mutator_lock_, !*gc_complete_lock_); 984 985 // Find a collector based on GC type. 986 collector::GarbageCollector* FindCollectorByGcType(collector::GcType gc_type); 987 988 // Create the main free list malloc space, either a RosAlloc space or DlMalloc space. 989 void CreateMainMallocSpace(MemMap* mem_map, 990 size_t initial_size, 991 size_t growth_limit, 992 size_t capacity); 993 994 // Create a malloc space based on a mem map. Does not set the space as default. 995 space::MallocSpace* CreateMallocSpaceFromMemMap(MemMap* mem_map, 996 size_t initial_size, 997 size_t growth_limit, 998 size_t capacity, 999 const char* name, 1000 bool can_move_objects); 1001 1002 // Given the current contents of the alloc space, increase the allowed heap footprint to match 1003 // the target utilization ratio. This should only be called immediately after a full garbage 1004 // collection. bytes_allocated_before_gc is used to measure bytes / second for the period which 1005 // the GC was run. 1006 void GrowForUtilization(collector::GarbageCollector* collector_ran, 1007 uint64_t bytes_allocated_before_gc = 0); 1008 1009 size_t GetPercentFree(); 1010 1011 static void VerificationCallback(mirror::Object* obj, void* arg) 1012 REQUIRES_SHARED(Locks::heap_bitmap_lock_); 1013 1014 // Swap the allocation stack with the live stack. 1015 void SwapStacks() REQUIRES_SHARED(Locks::mutator_lock_); 1016 1017 // Clear cards and update the mod union table. When process_alloc_space_cards is true, 1018 // if clear_alloc_space_cards is true, then we clear cards instead of ageing them. We do 1019 // not process the alloc space if process_alloc_space_cards is false. 1020 void ProcessCards(TimingLogger* timings, 1021 bool use_rem_sets, 1022 bool process_alloc_space_cards, 1023 bool clear_alloc_space_cards) 1024 REQUIRES_SHARED(Locks::mutator_lock_); 1025 1026 // Push an object onto the allocation stack. 1027 void PushOnAllocationStack(Thread* self, ObjPtr<mirror::Object>* obj) 1028 REQUIRES_SHARED(Locks::mutator_lock_) 1029 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_); 1030 void PushOnAllocationStackWithInternalGC(Thread* self, ObjPtr<mirror::Object>* obj) 1031 REQUIRES_SHARED(Locks::mutator_lock_) 1032 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_); 1033 void PushOnThreadLocalAllocationStackWithInternalGC(Thread* thread, ObjPtr<mirror::Object>* obj) 1034 REQUIRES_SHARED(Locks::mutator_lock_) 1035 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_); 1036 1037 void ClearConcurrentGCRequest(); 1038 void ClearPendingTrim(Thread* self) REQUIRES(!*pending_task_lock_); 1039 void ClearPendingCollectorTransition(Thread* self) REQUIRES(!*pending_task_lock_); 1040 1041 // What kind of concurrency behavior is the runtime after? Currently true for concurrent mark 1042 // sweep GC, false for other GC types. 1043 bool IsGcConcurrent() const ALWAYS_INLINE { 1044 return collector_type_ == kCollectorTypeCMS || 1045 collector_type_ == kCollectorTypeCC || 1046 collector_type_ == kCollectorTypeCCBackground; 1047 } 1048 1049 // Trim the managed and native spaces by releasing unused memory back to the OS. 1050 void TrimSpaces(Thread* self) REQUIRES(!*gc_complete_lock_); 1051 1052 // Trim 0 pages at the end of reference tables. 1053 void TrimIndirectReferenceTables(Thread* self); 1054 1055 void VisitObjectsInternal(ObjectCallback callback, void* arg) 1056 REQUIRES_SHARED(Locks::mutator_lock_) 1057 REQUIRES(!Locks::heap_bitmap_lock_, !*gc_complete_lock_); 1058 void VisitObjectsInternalRegionSpace(ObjectCallback callback, void* arg) 1059 REQUIRES(Locks::mutator_lock_, !Locks::heap_bitmap_lock_, !*gc_complete_lock_); 1060 1061 void UpdateGcCountRateHistograms() REQUIRES(gc_complete_lock_); 1062 1063 // GC stress mode attempts to do one GC per unique backtrace. 1064 void CheckGcStressMode(Thread* self, ObjPtr<mirror::Object>* obj) 1065 REQUIRES_SHARED(Locks::mutator_lock_) 1066 REQUIRES(!*gc_complete_lock_, !*pending_task_lock_, !*backtrace_lock_); 1067 1068 collector::GcType NonStickyGcType() const { 1069 return HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 1070 } 1071 1072 // How large new_native_bytes_allocated_ can grow before we trigger a new 1073 // GC. 1074 ALWAYS_INLINE size_t NativeAllocationGcWatermark() const { 1075 // Reuse max_free_ for the native allocation gc watermark, so that the 1076 // native heap is treated in the same way as the Java heap in the case 1077 // where the gc watermark update would exceed max_free_. Using max_free_ 1078 // instead of the target utilization means the watermark doesn't depend on 1079 // the current number of registered native allocations. 1080 return max_free_; 1081 } 1082 1083 // How large new_native_bytes_allocated_ can grow while GC is in progress 1084 // before we block the allocating thread to allow GC to catch up. 1085 ALWAYS_INLINE size_t NativeAllocationBlockingGcWatermark() const { 1086 // Historically the native allocations were bounded by growth_limit_. This 1087 // uses that same value, dividing growth_limit_ by 2 to account for 1088 // the fact that now the bound is relative to the number of retained 1089 // registered native allocations rather than absolute. 1090 return growth_limit_ / 2; 1091 } 1092 1093 // All-known continuous spaces, where objects lie within fixed bounds. 1094 std::vector<space::ContinuousSpace*> continuous_spaces_ GUARDED_BY(Locks::mutator_lock_); 1095 1096 // All-known discontinuous spaces, where objects may be placed throughout virtual memory. 1097 std::vector<space::DiscontinuousSpace*> discontinuous_spaces_ GUARDED_BY(Locks::mutator_lock_); 1098 1099 // All-known alloc spaces, where objects may be or have been allocated. 1100 std::vector<space::AllocSpace*> alloc_spaces_; 1101 1102 // A space where non-movable objects are allocated, when compaction is enabled it contains 1103 // Classes, ArtMethods, ArtFields, and non moving objects. 1104 space::MallocSpace* non_moving_space_; 1105 1106 // Space which we use for the kAllocatorTypeROSAlloc. 1107 space::RosAllocSpace* rosalloc_space_; 1108 1109 // Space which we use for the kAllocatorTypeDlMalloc. 1110 space::DlMallocSpace* dlmalloc_space_; 1111 1112 // The main space is the space which the GC copies to and from on process state updates. This 1113 // space is typically either the dlmalloc_space_ or the rosalloc_space_. 1114 space::MallocSpace* main_space_; 1115 1116 // The large object space we are currently allocating into. 1117 space::LargeObjectSpace* large_object_space_; 1118 1119 // The card table, dirtied by the write barrier. 1120 std::unique_ptr<accounting::CardTable> card_table_; 1121 1122 std::unique_ptr<accounting::ReadBarrierTable> rb_table_; 1123 1124 // A mod-union table remembers all of the references from the it's space to other spaces. 1125 AllocationTrackingSafeMap<space::Space*, accounting::ModUnionTable*, kAllocatorTagHeap> 1126 mod_union_tables_; 1127 1128 // A remembered set remembers all of the references from the it's space to the target space. 1129 AllocationTrackingSafeMap<space::Space*, accounting::RememberedSet*, kAllocatorTagHeap> 1130 remembered_sets_; 1131 1132 // The current collector type. 1133 CollectorType collector_type_; 1134 // Which collector we use when the app is in the foreground. 1135 CollectorType foreground_collector_type_; 1136 // Which collector we will use when the app is notified of a transition to background. 1137 CollectorType background_collector_type_; 1138 // Desired collector type, heap trimming daemon transitions the heap if it is != collector_type_. 1139 CollectorType desired_collector_type_; 1140 1141 // Lock which guards pending tasks. 1142 Mutex* pending_task_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 1143 1144 // How many GC threads we may use for paused parts of garbage collection. 1145 const size_t parallel_gc_threads_; 1146 1147 // How many GC threads we may use for unpaused parts of garbage collection. 1148 const size_t conc_gc_threads_; 1149 1150 // Boolean for if we are in low memory mode. 1151 const bool low_memory_mode_; 1152 1153 // If we get a pause longer than long pause log threshold, then we print out the GC after it 1154 // finishes. 1155 const size_t long_pause_log_threshold_; 1156 1157 // If we get a GC longer than long GC log threshold, then we print out the GC after it finishes. 1158 const size_t long_gc_log_threshold_; 1159 1160 // If we ignore the max footprint it lets the heap grow until it hits the heap capacity, this is 1161 // useful for benchmarking since it reduces time spent in GC to a low %. 1162 const bool ignore_max_footprint_; 1163 1164 // Lock which guards zygote space creation. 1165 Mutex zygote_creation_lock_; 1166 1167 // Non-null iff we have a zygote space. Doesn't contain the large objects allocated before 1168 // zygote space creation. 1169 space::ZygoteSpace* zygote_space_; 1170 1171 // Minimum allocation size of large object. 1172 size_t large_object_threshold_; 1173 1174 // Guards access to the state of GC, associated conditional variable is used to signal when a GC 1175 // completes. 1176 Mutex* gc_complete_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 1177 std::unique_ptr<ConditionVariable> gc_complete_cond_ GUARDED_BY(gc_complete_lock_); 1178 1179 // Used to synchronize between JNI critical calls and the thread flip of the CC collector. 1180 Mutex* thread_flip_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 1181 std::unique_ptr<ConditionVariable> thread_flip_cond_ GUARDED_BY(thread_flip_lock_); 1182 // This counter keeps track of how many threads are currently in a JNI critical section. This is 1183 // incremented once per thread even with nested enters. 1184 size_t disable_thread_flip_count_ GUARDED_BY(thread_flip_lock_); 1185 bool thread_flip_running_ GUARDED_BY(thread_flip_lock_); 1186 1187 // Reference processor; 1188 std::unique_ptr<ReferenceProcessor> reference_processor_; 1189 1190 // Task processor, proxies heap trim requests to the daemon threads. 1191 std::unique_ptr<TaskProcessor> task_processor_; 1192 1193 // True while the garbage collector is running. 1194 volatile CollectorType collector_type_running_ GUARDED_BY(gc_complete_lock_); 1195 1196 // The thread currently running the GC. 1197 volatile Thread* thread_running_gc_ GUARDED_BY(gc_complete_lock_); 1198 1199 // Last Gc type we ran. Used by WaitForConcurrentGc to know which Gc was waited on. 1200 volatile collector::GcType last_gc_type_ GUARDED_BY(gc_complete_lock_); 1201 collector::GcType next_gc_type_; 1202 1203 // Maximum size that the heap can reach. 1204 size_t capacity_; 1205 1206 // The size the heap is limited to. This is initially smaller than capacity, but for largeHeap 1207 // programs it is "cleared" making it the same as capacity. 1208 size_t growth_limit_; 1209 1210 // When the number of bytes allocated exceeds the footprint TryAllocate returns null indicating 1211 // a GC should be triggered. 1212 size_t max_allowed_footprint_; 1213 1214 // When num_bytes_allocated_ exceeds this amount then a concurrent GC should be requested so that 1215 // it completes ahead of an allocation failing. 1216 size_t concurrent_start_bytes_; 1217 1218 // Since the heap was created, how many bytes have been freed. 1219 uint64_t total_bytes_freed_ever_; 1220 1221 // Since the heap was created, how many objects have been freed. 1222 uint64_t total_objects_freed_ever_; 1223 1224 // Number of bytes allocated. Adjusted after each allocation and free. 1225 Atomic<size_t> num_bytes_allocated_; 1226 1227 // Number of registered native bytes allocated since the last time GC was 1228 // triggered. Adjusted after each RegisterNativeAllocation and 1229 // RegisterNativeFree. Used to determine when to trigger GC for native 1230 // allocations. 1231 // See the REDESIGN section of go/understanding-register-native-allocation. 1232 Atomic<size_t> new_native_bytes_allocated_; 1233 1234 // Number of registered native bytes allocated prior to the last time GC was 1235 // triggered, for debugging purposes. The current number of registered 1236 // native bytes is determined by taking the sum of 1237 // old_native_bytes_allocated_ and new_native_bytes_allocated_. 1238 Atomic<size_t> old_native_bytes_allocated_; 1239 1240 // Used for synchronization of blocking GCs triggered by 1241 // RegisterNativeAllocation. 1242 Mutex* native_blocking_gc_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 1243 std::unique_ptr<ConditionVariable> native_blocking_gc_cond_ GUARDED_BY(native_blocking_gc_lock_); 1244 bool native_blocking_gc_in_progress_ GUARDED_BY(native_blocking_gc_lock_); 1245 uint32_t native_blocking_gcs_finished_ GUARDED_BY(native_blocking_gc_lock_); 1246 1247 // Number of bytes freed by thread local buffer revokes. This will 1248 // cancel out the ahead-of-time bulk counting of bytes allocated in 1249 // rosalloc thread-local buffers. It is temporarily accumulated 1250 // here to be subtracted from num_bytes_allocated_ later at the next 1251 // GC. 1252 Atomic<size_t> num_bytes_freed_revoke_; 1253 1254 // Info related to the current or previous GC iteration. 1255 collector::Iteration current_gc_iteration_; 1256 1257 // Heap verification flags. 1258 const bool verify_missing_card_marks_; 1259 const bool verify_system_weaks_; 1260 const bool verify_pre_gc_heap_; 1261 const bool verify_pre_sweeping_heap_; 1262 const bool verify_post_gc_heap_; 1263 const bool verify_mod_union_table_; 1264 bool verify_pre_gc_rosalloc_; 1265 bool verify_pre_sweeping_rosalloc_; 1266 bool verify_post_gc_rosalloc_; 1267 const bool gc_stress_mode_; 1268 1269 // RAII that temporarily disables the rosalloc verification during 1270 // the zygote fork. 1271 class ScopedDisableRosAllocVerification { 1272 private: 1273 Heap* const heap_; 1274 const bool orig_verify_pre_gc_; 1275 const bool orig_verify_pre_sweeping_; 1276 const bool orig_verify_post_gc_; 1277 1278 public: 1279 explicit ScopedDisableRosAllocVerification(Heap* heap) 1280 : heap_(heap), 1281 orig_verify_pre_gc_(heap_->verify_pre_gc_rosalloc_), 1282 orig_verify_pre_sweeping_(heap_->verify_pre_sweeping_rosalloc_), 1283 orig_verify_post_gc_(heap_->verify_post_gc_rosalloc_) { 1284 heap_->verify_pre_gc_rosalloc_ = false; 1285 heap_->verify_pre_sweeping_rosalloc_ = false; 1286 heap_->verify_post_gc_rosalloc_ = false; 1287 } 1288 ~ScopedDisableRosAllocVerification() { 1289 heap_->verify_pre_gc_rosalloc_ = orig_verify_pre_gc_; 1290 heap_->verify_pre_sweeping_rosalloc_ = orig_verify_pre_sweeping_; 1291 heap_->verify_post_gc_rosalloc_ = orig_verify_post_gc_; 1292 } 1293 }; 1294 1295 // Parallel GC data structures. 1296 std::unique_ptr<ThreadPool> thread_pool_; 1297 1298 // Estimated allocation rate (bytes / second). Computed between the time of the last GC cycle 1299 // and the start of the current one. 1300 uint64_t allocation_rate_; 1301 1302 // For a GC cycle, a bitmap that is set corresponding to the 1303 std::unique_ptr<accounting::HeapBitmap> live_bitmap_ GUARDED_BY(Locks::heap_bitmap_lock_); 1304 std::unique_ptr<accounting::HeapBitmap> mark_bitmap_ GUARDED_BY(Locks::heap_bitmap_lock_); 1305 1306 // Mark stack that we reuse to avoid re-allocating the mark stack. 1307 std::unique_ptr<accounting::ObjectStack> mark_stack_; 1308 1309 // Allocation stack, new allocations go here so that we can do sticky mark bits. This enables us 1310 // to use the live bitmap as the old mark bitmap. 1311 const size_t max_allocation_stack_size_; 1312 std::unique_ptr<accounting::ObjectStack> allocation_stack_; 1313 1314 // Second allocation stack so that we can process allocation with the heap unlocked. 1315 std::unique_ptr<accounting::ObjectStack> live_stack_; 1316 1317 // Allocator type. 1318 AllocatorType current_allocator_; 1319 const AllocatorType current_non_moving_allocator_; 1320 1321 // Which GCs we run in order when we an allocation fails. 1322 std::vector<collector::GcType> gc_plan_; 1323 1324 // Bump pointer spaces. 1325 space::BumpPointerSpace* bump_pointer_space_; 1326 // Temp space is the space which the semispace collector copies to. 1327 space::BumpPointerSpace* temp_space_; 1328 1329 space::RegionSpace* region_space_; 1330 1331 // Minimum free guarantees that you always have at least min_free_ free bytes after growing for 1332 // utilization, regardless of target utilization ratio. 1333 size_t min_free_; 1334 1335 // The ideal maximum free size, when we grow the heap for utilization. 1336 size_t max_free_; 1337 1338 // Target ideal heap utilization ratio 1339 double target_utilization_; 1340 1341 // How much more we grow the heap when we are a foreground app instead of background. 1342 double foreground_heap_growth_multiplier_; 1343 1344 // Total time which mutators are paused or waiting for GC to complete. 1345 uint64_t total_wait_time_; 1346 1347 // The current state of heap verification, may be enabled or disabled. 1348 VerifyObjectMode verify_object_mode_; 1349 1350 // Compacting GC disable count, prevents compacting GC from running iff > 0. 1351 size_t disable_moving_gc_count_ GUARDED_BY(gc_complete_lock_); 1352 1353 std::vector<collector::GarbageCollector*> garbage_collectors_; 1354 collector::SemiSpace* semi_space_collector_; 1355 collector::MarkCompact* mark_compact_collector_; 1356 collector::ConcurrentCopying* concurrent_copying_collector_; 1357 1358 const bool is_running_on_memory_tool_; 1359 const bool use_tlab_; 1360 1361 // Pointer to the space which becomes the new main space when we do homogeneous space compaction. 1362 // Use unique_ptr since the space is only added during the homogeneous compaction phase. 1363 std::unique_ptr<space::MallocSpace> main_space_backup_; 1364 1365 // Minimal interval allowed between two homogeneous space compactions caused by OOM. 1366 uint64_t min_interval_homogeneous_space_compaction_by_oom_; 1367 1368 // Times of the last homogeneous space compaction caused by OOM. 1369 uint64_t last_time_homogeneous_space_compaction_by_oom_; 1370 1371 // Saved OOMs by homogeneous space compaction. 1372 Atomic<size_t> count_delayed_oom_; 1373 1374 // Count for requested homogeneous space compaction. 1375 Atomic<size_t> count_requested_homogeneous_space_compaction_; 1376 1377 // Count for ignored homogeneous space compaction. 1378 Atomic<size_t> count_ignored_homogeneous_space_compaction_; 1379 1380 // Count for performed homogeneous space compaction. 1381 Atomic<size_t> count_performed_homogeneous_space_compaction_; 1382 1383 // Whether or not a concurrent GC is pending. 1384 Atomic<bool> concurrent_gc_pending_; 1385 1386 // Active tasks which we can modify (change target time, desired collector type, etc..). 1387 CollectorTransitionTask* pending_collector_transition_ GUARDED_BY(pending_task_lock_); 1388 HeapTrimTask* pending_heap_trim_ GUARDED_BY(pending_task_lock_); 1389 1390 // Whether or not we use homogeneous space compaction to avoid OOM errors. 1391 bool use_homogeneous_space_compaction_for_oom_; 1392 1393 // True if the currently running collection has made some thread wait. 1394 bool running_collection_is_blocking_ GUARDED_BY(gc_complete_lock_); 1395 // The number of blocking GC runs. 1396 uint64_t blocking_gc_count_; 1397 // The total duration of blocking GC runs. 1398 uint64_t blocking_gc_time_; 1399 // The duration of the window for the GC count rate histograms. 1400 static constexpr uint64_t kGcCountRateHistogramWindowDuration = MsToNs(10 * 1000); // 10s. 1401 // The last time when the GC count rate histograms were updated. 1402 // This is rounded by kGcCountRateHistogramWindowDuration (a multiple of 10s). 1403 uint64_t last_update_time_gc_count_rate_histograms_; 1404 // The running count of GC runs in the last window. 1405 uint64_t gc_count_last_window_; 1406 // The running count of blocking GC runs in the last window. 1407 uint64_t blocking_gc_count_last_window_; 1408 // The maximum number of buckets in the GC count rate histograms. 1409 static constexpr size_t kGcCountRateMaxBucketCount = 200; 1410 // The histogram of the number of GC invocations per window duration. 1411 Histogram<uint64_t> gc_count_rate_histogram_ GUARDED_BY(gc_complete_lock_); 1412 // The histogram of the number of blocking GC invocations per window duration. 1413 Histogram<uint64_t> blocking_gc_count_rate_histogram_ GUARDED_BY(gc_complete_lock_); 1414 1415 // Allocation tracking support 1416 Atomic<bool> alloc_tracking_enabled_; 1417 std::unique_ptr<AllocRecordObjectMap> allocation_records_; 1418 1419 // GC stress related data structures. 1420 Mutex* backtrace_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 1421 // Debugging variables, seen backtraces vs unique backtraces. 1422 Atomic<uint64_t> seen_backtrace_count_; 1423 Atomic<uint64_t> unique_backtrace_count_; 1424 // Stack trace hashes that we already saw, 1425 std::unordered_set<uint64_t> seen_backtraces_ GUARDED_BY(backtrace_lock_); 1426 1427 // We disable GC when we are shutting down the runtime in case there are daemon threads still 1428 // allocating. 1429 bool gc_disabled_for_shutdown_ GUARDED_BY(gc_complete_lock_); 1430 1431 // Boot image spaces. 1432 std::vector<space::ImageSpace*> boot_image_spaces_; 1433 1434 // An installed allocation listener. 1435 Atomic<AllocationListener*> alloc_listener_; 1436 // An installed GC Pause listener. 1437 Atomic<GcPauseListener*> gc_pause_listener_; 1438 1439 std::unique_ptr<Verification> verification_; 1440 1441 friend class CollectorTransitionTask; 1442 friend class collector::GarbageCollector; 1443 friend class collector::MarkCompact; 1444 friend class collector::ConcurrentCopying; 1445 friend class collector::MarkSweep; 1446 friend class collector::SemiSpace; 1447 friend class ReferenceQueue; 1448 friend class ScopedGCCriticalSection; 1449 friend class VerifyReferenceCardVisitor; 1450 friend class VerifyReferenceVisitor; 1451 friend class VerifyObjectVisitor; 1452 1453 DISALLOW_IMPLICIT_CONSTRUCTORS(Heap); 1454 }; 1455 1456 } // namespace gc 1457 } // namespace art 1458 1459 #endif // ART_RUNTIME_GC_HEAP_H_ 1460
