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- /*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- #ifndef GrMemoryPool_DEFINED
- #define GrMemoryPool_DEFINED
- #include "include/gpu/GrTypes.h"
- #include "include/core/SkRefCnt.h"
- #ifdef SK_DEBUG
- #include "include/private/SkTHash.h"
- #endif
- /**
- * Allocates memory in blocks and parcels out space in the blocks for allocation
- * requests. It is optimized for allocate / release speed over memory
- * efficiency. The interface is designed to be used to implement operator new
- * and delete overrides. All allocations are expected to be released before the
- * pool's destructor is called. Allocations will be 8-byte aligned.
- */
- class GrMemoryPool {
- public:
- /**
- * Prealloc size is the amount of space to allocate at pool creation
- * time and keep around until pool destruction. The min alloc size is
- * the smallest allowed size of additional allocations. Both sizes are
- * adjusted to ensure that:
- * 1. they are are 8-byte aligned
- * 2. minAllocSize >= kSmallestMinAllocSize
- * 3. preallocSize >= minAllocSize
- *
- * Both sizes is what the pool will end up allocating from the system, and
- * portions of the allocated memory is used for internal bookkeeping.
- */
- GrMemoryPool(size_t preallocSize, size_t minAllocSize);
- ~GrMemoryPool();
- /**
- * Allocates memory. The memory must be freed with release().
- */
- void* allocate(size_t size);
- /**
- * p must have been returned by allocate()
- */
- void release(void* p);
- /**
- * Returns true if there are no unreleased allocations.
- */
- bool isEmpty() const { return fTail == fHead && !fHead->fLiveCount; }
- /**
- * Returns the total allocated size of the GrMemoryPool minus any preallocated amount
- */
- size_t size() const { return fSize; }
- /**
- * Returns the preallocated size of the GrMemoryPool
- */
- size_t preallocSize() const { return fHead->fSize; }
- /**
- * Minimum value of minAllocSize constructor argument.
- */
- constexpr static size_t kSmallestMinAllocSize = 1 << 10;
- private:
- struct BlockHeader;
- static BlockHeader* CreateBlock(size_t size);
- static void DeleteBlock(BlockHeader* block);
- void validate();
- struct BlockHeader {
- #ifdef SK_DEBUG
- uint32_t fBlockSentinal; ///< known value to check for bad back pointers to blocks
- #endif
- BlockHeader* fNext; ///< doubly-linked list of blocks.
- BlockHeader* fPrev;
- int fLiveCount; ///< number of outstanding allocations in the
- ///< block.
- intptr_t fCurrPtr; ///< ptr to the start of blocks free space.
- intptr_t fPrevPtr; ///< ptr to the last allocation made
- size_t fFreeSize; ///< amount of free space left in the block.
- size_t fSize; ///< total allocated size of the block
- };
- static const uint32_t kAssignedMarker = 0xCDCDCDCD;
- static const uint32_t kFreedMarker = 0xEFEFEFEF;
- struct AllocHeader {
- #ifdef SK_DEBUG
- uint32_t fSentinal; ///< known value to check for memory stomping (e.g., (CD)*)
- int32_t fID; ///< ID that can be used to track down leaks by clients.
- #endif
- BlockHeader* fHeader; ///< pointer back to the block header in which an alloc resides
- };
- size_t fSize;
- size_t fMinAllocSize;
- BlockHeader* fHead;
- BlockHeader* fTail;
- #ifdef SK_DEBUG
- int fAllocationCnt;
- int fAllocBlockCnt;
- SkTHashSet<int32_t> fAllocatedIDs;
- #endif
- protected:
- enum {
- // We assume this alignment is good enough for everybody.
- kAlignment = 8,
- kHeaderSize = GrSizeAlignUp(sizeof(BlockHeader), kAlignment),
- kPerAllocPad = GrSizeAlignUp(sizeof(AllocHeader), kAlignment),
- };
- };
- class GrOp;
- // DDL TODO: for the DLL use case this could probably be the non-intrinsic-based style of
- // ref counting
- class GrOpMemoryPool : public SkRefCnt {
- public:
- GrOpMemoryPool(size_t preallocSize, size_t minAllocSize)
- : fMemoryPool(preallocSize, minAllocSize) {
- }
- template <typename Op, typename... OpArgs>
- std::unique_ptr<Op> allocate(OpArgs&&... opArgs) {
- char* mem = (char*) fMemoryPool.allocate(sizeof(Op));
- return std::unique_ptr<Op>(new (mem) Op(std::forward<OpArgs>(opArgs)...));
- }
- void* allocate(size_t size) {
- return fMemoryPool.allocate(size);
- }
- void release(std::unique_ptr<GrOp> op);
- bool isEmpty() const { return fMemoryPool.isEmpty(); }
- private:
- GrMemoryPool fMemoryPool;
- };
- #endif
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