| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ART_RUNTIME_GC_SPACE_BUMP_POINTER_SPACE_H_ |
| #define ART_RUNTIME_GC_SPACE_BUMP_POINTER_SPACE_H_ |
| |
| #include "object_callbacks.h" |
| #include "space.h" |
| |
| namespace art { |
| namespace gc { |
| |
| namespace collector { |
| class MarkSweep; |
| } // namespace collector |
| |
| namespace space { |
| |
| // A bump pointer space allocates by incrementing a pointer, it doesn't provide a free |
| // implementation as its intended to be evacuated. |
| class BumpPointerSpace FINAL : public ContinuousMemMapAllocSpace { |
| public: |
| typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg); |
| |
| SpaceType GetType() const OVERRIDE { |
| return kSpaceTypeBumpPointerSpace; |
| } |
| |
| // Create a bump pointer space with the requested sizes. The requested base address is not |
| // guaranteed to be granted, if it is required, the caller should call Begin on the returned |
| // space to confirm the request was granted. |
| static BumpPointerSpace* Create(const std::string& name, size_t capacity, uint8_t* requested_begin); |
| static BumpPointerSpace* CreateFromMemMap(const std::string& name, MemMap* mem_map); |
| |
| // Allocate num_bytes, returns nullptr if the space is full. |
| mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated, |
| size_t* usable_size) OVERRIDE; |
| // Thread-unsafe allocation for when mutators are suspended, used by the semispace collector. |
| mirror::Object* AllocThreadUnsafe(Thread* self, size_t num_bytes, size_t* bytes_allocated, |
| size_t* usable_size) |
| OVERRIDE EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| mirror::Object* AllocNonvirtual(size_t num_bytes); |
| mirror::Object* AllocNonvirtualWithoutAccounting(size_t num_bytes); |
| |
| // Return the storage space required by obj. |
| size_t AllocationSize(mirror::Object* obj, size_t* usable_size) OVERRIDE |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
| return AllocationSizeNonvirtual(obj, usable_size); |
| } |
| |
| // NOPS unless we support free lists. |
| size_t Free(Thread*, mirror::Object*) OVERRIDE { |
| return 0; |
| } |
| |
| size_t FreeList(Thread*, size_t, mirror::Object**) OVERRIDE { |
| return 0; |
| } |
| |
| size_t AllocationSizeNonvirtual(mirror::Object* obj, size_t* usable_size) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Removes the fork time growth limit on capacity, allowing the application to allocate up to the |
| // maximum reserved size of the heap. |
| void ClearGrowthLimit() { |
| growth_end_ = Limit(); |
| } |
| |
| // Override capacity so that we only return the possibly limited capacity |
| size_t Capacity() const { |
| return growth_end_ - begin_; |
| } |
| |
| // The total amount of memory reserved for the space. |
| size_t NonGrowthLimitCapacity() const { |
| return GetMemMap()->Size(); |
| } |
| |
| accounting::ContinuousSpaceBitmap* GetLiveBitmap() const OVERRIDE { |
| return nullptr; |
| } |
| |
| accounting::ContinuousSpaceBitmap* GetMarkBitmap() const OVERRIDE { |
| return nullptr; |
| } |
| |
| // Reset the space to empty. |
| void Clear() OVERRIDE LOCKS_EXCLUDED(block_lock_); |
| |
| void Dump(std::ostream& os) const; |
| |
| void RevokeThreadLocalBuffers(Thread* thread) LOCKS_EXCLUDED(block_lock_); |
| void RevokeAllThreadLocalBuffers() LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_, |
| Locks::thread_list_lock_); |
| void AssertThreadLocalBuffersAreRevoked(Thread* thread) LOCKS_EXCLUDED(block_lock_); |
| void AssertAllThreadLocalBuffersAreRevoked() LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_, |
| Locks::thread_list_lock_); |
| |
| uint64_t GetBytesAllocated() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| uint64_t GetObjectsAllocated() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| bool IsEmpty() const { |
| return Begin() == End(); |
| } |
| |
| bool CanMoveObjects() const OVERRIDE { |
| return true; |
| } |
| |
| bool Contains(const mirror::Object* obj) const { |
| const uint8_t* byte_obj = reinterpret_cast<const uint8_t*>(obj); |
| return byte_obj >= Begin() && byte_obj < End(); |
| } |
| |
| // TODO: Change this? Mainly used for compacting to a particular region of memory. |
| BumpPointerSpace(const std::string& name, uint8_t* begin, uint8_t* limit); |
| |
| // Return the object which comes after obj, while ensuring alignment. |
| static mirror::Object* GetNextObject(mirror::Object* obj) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Allocate a new TLAB, returns false if the allocation failed. |
| bool AllocNewTlab(Thread* self, size_t bytes); |
| |
| BumpPointerSpace* AsBumpPointerSpace() OVERRIDE { |
| return this; |
| } |
| |
| // Go through all of the blocks and visit the continuous objects. |
| void Walk(ObjectCallback* callback, void* arg) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| accounting::ContinuousSpaceBitmap::SweepCallback* GetSweepCallback() OVERRIDE; |
| |
| // Record objects / bytes freed. |
| void RecordFree(int32_t objects, int32_t bytes) { |
| objects_allocated_.FetchAndSubSequentiallyConsistent(objects); |
| bytes_allocated_.FetchAndSubSequentiallyConsistent(bytes); |
| } |
| |
| void LogFragmentationAllocFailure(std::ostream& os, size_t failed_alloc_bytes) OVERRIDE |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Object alignment within the space. |
| static constexpr size_t kAlignment = 8; |
| |
| protected: |
| BumpPointerSpace(const std::string& name, MemMap* mem_map); |
| |
| // Allocate a raw block of bytes. |
| uint8_t* AllocBlock(size_t bytes) EXCLUSIVE_LOCKS_REQUIRED(block_lock_); |
| void RevokeThreadLocalBuffersLocked(Thread* thread) EXCLUSIVE_LOCKS_REQUIRED(block_lock_); |
| |
| // The main block is an unbounded block where objects go when there are no other blocks. This |
| // enables us to maintain tightly packed objects when you are not using thread local buffers for |
| // allocation. The main block starts at the space Begin(). |
| void UpdateMainBlock() EXCLUSIVE_LOCKS_REQUIRED(block_lock_); |
| |
| uint8_t* growth_end_; |
| AtomicInteger objects_allocated_; // Accumulated from revoked thread local regions. |
| AtomicInteger bytes_allocated_; // Accumulated from revoked thread local regions. |
| Mutex block_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; |
| // The objects at the start of the space are stored in the main block. The main block doesn't |
| // have a header, this lets us walk empty spaces which are mprotected. |
| size_t main_block_size_ GUARDED_BY(block_lock_); |
| // The number of blocks in the space, if it is 0 then the space has one long continuous block |
| // which doesn't have an updated header. |
| size_t num_blocks_ GUARDED_BY(block_lock_); |
| |
| private: |
| struct BlockHeader { |
| size_t size_; // Size of the block in bytes, does not include the header. |
| size_t unused_; // Ensures alignment of kAlignment. |
| }; |
| |
| COMPILE_ASSERT(sizeof(BlockHeader) % kAlignment == 0, |
| continuous_block_must_be_kAlignment_aligned); |
| |
| friend class collector::MarkSweep; |
| DISALLOW_COPY_AND_ASSIGN(BumpPointerSpace); |
| }; |
| |
| } // namespace space |
| } // namespace gc |
| } // namespace art |
| |
| #endif // ART_RUNTIME_GC_SPACE_BUMP_POINTER_SPACE_H_ |