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/*
* 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 "space.h"
namespace art {
namespace gc {
namespace collector {
class MarkSweep;
} // namespace collector
namespace space {
// A bump pointer space is a space where objects may be allocated and garbage collected.
class BumpPointerSpace : public ContinuousMemMapAllocSpace {
public:
typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg);
SpaceType GetType() const {
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, byte* requested_begin);
// Allocate num_bytes, returns nullptr if the space is full.
virtual mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated);
mirror::Object* AllocNonvirtual(size_t num_bytes);
// Return the storage space required by obj.
virtual size_t AllocationSize(const mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Nos unless we support free lists.
virtual size_t Free(Thread*, mirror::Object*) {
return 0;
}
virtual size_t FreeList(Thread*, size_t, mirror::Object**) {
return 0;
}
size_t AllocationSizeNonvirtual(const mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return obj->SizeOf();
}
// 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::SpaceBitmap* GetLiveBitmap() const {
return nullptr;
}
accounting::SpaceBitmap* GetMarkBitmap() const {
return nullptr;
}
// Clear the memory and reset the pointer to the start of the space.
void Clear();
void Dump(std::ostream& os) const;
uint64_t GetBytesAllocated() {
return Size();
}
uint64_t GetObjectsAllocated() {
return num_objects_allocated_;
}
uint64_t GetTotalBytesAllocated() {
return total_bytes_allocated_;
}
uint64_t GetTotalObjectsAllocated() {
return total_objects_allocated_;
}
bool Contains(const mirror::Object* obj) const {
const byte* byte_obj = reinterpret_cast<const byte*>(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, byte* begin, byte* limit);
// Return the object which comes after obj, while ensuring alignment.
static mirror::Object* GetNextObject(mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Alignment.
static constexpr size_t kAlignment = 8;
protected:
BumpPointerSpace(const std::string& name, MemMap* mem_map);
size_t InternalAllocationSize(const mirror::Object* obj);
mirror::Object* AllocWithoutGrowthLocked(size_t num_bytes, size_t* bytes_allocated)
EXCLUSIVE_LOCKS_REQUIRED(lock_);
// Approximate number of bytes which have been allocated into the space.
AtomicInteger num_objects_allocated_;
AtomicInteger total_bytes_allocated_;
AtomicInteger total_objects_allocated_;
byte* growth_end_;
private:
friend class collector::MarkSweep;
DISALLOW_COPY_AND_ASSIGN(BumpPointerSpace);
};
} // namespace space
} // namespace gc
} // namespace art
#endif // ART_RUNTIME_GC_SPACE_BUMP_POINTER_SPACE_H_
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