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/*
* Copyright (C) 2012 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_SRC_GC_SPACE_LARGE_OBJECT_SPACE_H_
#define ART_SRC_GC_SPACE_LARGE_OBJECT_SPACE_H_
#include "dlmalloc_space.h"
#include "safe_map.h"
#include "space.h"
#include <set>
#include <vector>
namespace art {
namespace gc {
namespace space {
// Abstraction implemented by all large object spaces.
class LargeObjectSpace : public DiscontinuousSpace, public AllocSpace {
public:
virtual SpaceType GetType() const {
return kSpaceTypeLargeObjectSpace;
}
virtual void SwapBitmaps();
virtual void CopyLiveToMarked();
virtual void Walk(DlMallocSpace::WalkCallback, void* arg) = 0;
virtual ~LargeObjectSpace() {}
uint64_t GetBytesAllocated() const {
return num_bytes_allocated_;
}
uint64_t GetObjectsAllocated() const {
return num_objects_allocated_;
}
uint64_t GetTotalBytesAllocated() const {
return total_bytes_allocated_;
}
uint64_t GetTotalObjectsAllocated() const {
return total_objects_allocated_;
}
size_t FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs);
protected:
LargeObjectSpace(const std::string& name);
// Approximate number of bytes which have been allocated into the space.
size_t num_bytes_allocated_;
size_t num_objects_allocated_;
size_t total_bytes_allocated_;
size_t total_objects_allocated_;
friend class Space;
private:
DISALLOW_COPY_AND_ASSIGN(LargeObjectSpace);
};
// A discontinuous large object space implemented by individual mmap/munmap calls.
class LargeObjectMapSpace : public LargeObjectSpace {
public:
// Creates a large object space. Allocations into the large object space use memory maps instead
// of malloc.
static LargeObjectMapSpace* Create(const std::string& name);
// Return the storage space required by obj.
size_t AllocationSize(const mirror::Object* obj);
mirror::Object* Alloc(Thread* self, size_t num_bytes);
size_t Free(Thread* self, mirror::Object* ptr);
void Walk(DlMallocSpace::WalkCallback, void* arg);
// TODO: disabling thread safety analysis as this may be called when we already hold lock_.
bool Contains(const mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS;
private:
LargeObjectMapSpace(const std::string& name);
virtual ~LargeObjectMapSpace() {}
// Used to ensure mutual exclusion when the allocation spaces data structures are being modified.
mutable Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
std::vector<mirror::Object*> large_objects_ GUARDED_BY(lock_);
typedef SafeMap<mirror::Object*, MemMap*> MemMaps;
MemMaps mem_maps_ GUARDED_BY(lock_);
};
// A continuous large object space with a free-list to handle holes.
// TODO: this implementation is buggy.
class FreeListSpace : public LargeObjectSpace {
public:
virtual ~FreeListSpace();
static FreeListSpace* Create(const std::string& name, byte* requested_begin, size_t capacity);
size_t AllocationSize(const mirror::Object* obj) EXCLUSIVE_LOCKS_REQUIRED(lock_);
mirror::Object* Alloc(Thread* self, size_t num_bytes);
size_t Free(Thread* self, mirror::Object* obj);
bool Contains(const mirror::Object* obj) const;
void Walk(DlMallocSpace::WalkCallback callback, void* arg);
// Address at which the space begins.
byte* Begin() const {
return begin_;
}
// Address at which the space ends, which may vary as the space is filled.
byte* End() const {
return end_;
}
// Current size of space
size_t Size() const {
return End() - Begin();
}
void Dump(std::ostream& os) const;
private:
static const size_t kAlignment = kPageSize;
class Chunk {
public:
static const size_t kFreeFlag = 0x80000000;
struct SortBySize {
bool operator()(const Chunk* a, const Chunk* b) const {
return a->GetSize() < b->GetSize();
}
};
bool IsFree() const {
return (m_size & kFreeFlag) != 0;
}
void SetSize(size_t size, bool is_free = false) {
m_size = size | (is_free ? kFreeFlag : 0);
}
size_t GetSize() const {
return m_size & (kFreeFlag - 1);
}
Chunk* GetPrevious() {
return m_previous;
}
void SetPrevious(Chunk* previous) {
m_previous = previous;
DCHECK(m_previous == NULL ||
(m_previous != NULL && m_previous + m_previous->GetSize() / kAlignment == this));
}
private:
size_t m_size;
Chunk* m_previous;
};
FreeListSpace(const std::string& name, MemMap* mem_map, byte* begin, byte* end);
void AddFreeChunk(void* address, size_t size, Chunk* previous) EXCLUSIVE_LOCKS_REQUIRED(lock_);
Chunk* ChunkFromAddr(void* address) EXCLUSIVE_LOCKS_REQUIRED(lock_);
void* AddrFromChunk(Chunk* chunk) EXCLUSIVE_LOCKS_REQUIRED(lock_);
void RemoveFreeChunk(Chunk* chunk) EXCLUSIVE_LOCKS_REQUIRED(lock_);
Chunk* GetNextChunk(Chunk* chunk);
typedef std::multiset<Chunk*, Chunk::SortBySize> FreeChunks;
byte* const begin_;
byte* const end_;
UniquePtr<MemMap> mem_map_;
Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
std::vector<Chunk> chunks_ GUARDED_BY(lock_);
FreeChunks free_chunks_ GUARDED_BY(lock_);
};
} // namespace space
} // namespace gc
} // namespace art
#endif // ART_SRC_GC_SPACE_LARGE_OBJECT_SPACE_H_
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