Pull out freelist allocation from GrVkSubHeap

src/gpu/vk/GrVkMemory.h

 /*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #ifndef GrVkMemory_DEFINED
 #define GrVkMemory_DEFINED
 
@@ skipping 21 matching lines @@
                                  VkImage image,
                                  bool linearTiling,
                                  GrVkAlloc* alloc);
     void FreeImageMemory(const GrVkGpu* gpu, bool linearTiling, const GrVkAlloc& alloc);
 
     VkPipelineStageFlags LayoutToPipelineStageFlags(const VkImageLayout layout);
 
     VkAccessFlags LayoutToSrcAccessMask(const VkImageLayout layout);
 }
 
-class GrVkSubHeap {
+class GrVkFreeListAlloc {
 public:
-    GrVkSubHeap(const GrVkGpu* gpu, uint32_t memoryTypeIndex, 
-                VkDeviceSize size, VkDeviceSize alignment);
-    ~GrVkSubHeap();
+    GrVkFreeListAlloc(VkDeviceSize size, VkDeviceSize alignment)
+        : fSize(size)
+        , fAlignment(alignment)
+        , fFreeSize(size)
+        , fLargestBlockSize(size)
+        , fLargestBlockOffset(0) {
+        Block* block = fFreeList.addToTail();
+        block->fOffset = 0;
+        block->fSize = fSize;
+    }
+    ~GrVkFreeListAlloc() {
+        this->reset();
+    }
 
-    uint32_t  memoryTypeIndex() const { return fMemoryTypeIndex;  }
     VkDeviceSize size() const { return fSize; }
     VkDeviceSize alignment() const { return fAlignment; }
     VkDeviceSize freeSize() const { return fFreeSize; }
     VkDeviceSize largestBlockSize() const { return fLargestBlockSize; }
-    VkDeviceMemory memory() { return fAlloc; }
 
     bool unallocated() const { return fSize == fFreeSize; }
 
-    bool alloc(VkDeviceSize size, GrVkAlloc* alloc);
-    void free(const GrVkAlloc& alloc);
+protected:
+    bool alloc(VkDeviceSize requestedSize, VkDeviceSize* allocOffset, VkDeviceSize* allocSize);
+    void free(VkDeviceSize allocOffset, VkDeviceSize allocSize);
 
-private:
+    void reset() {
+        fSize = 0;
+        fAlignment = 0;
+        fFreeSize = 0;
+        fLargestBlockSize = 0;
+        fFreeList.reset();
+    }
+
     struct Block {
         VkDeviceSize fOffset;
         VkDeviceSize fSize;
     };
     typedef SkTLList<Block, 16> FreeList;
 
-    const GrVkGpu* fGpu;
-    uint32_t       fMemoryTypeIndex;
     VkDeviceSize   fSize;
     VkDeviceSize   fAlignment;
     VkDeviceSize   fFreeSize;
     VkDeviceSize   fLargestBlockSize;
     VkDeviceSize   fLargestBlockOffset;
+    FreeList       fFreeList;
+};
+
+class GrVkSubHeap : public GrVkFreeListAlloc {
+public:
+    GrVkSubHeap(const GrVkGpu* gpu, uint32_t memoryTypeIndex,
+                VkDeviceSize size, VkDeviceSize alignment);
+    ~GrVkSubHeap();
+
+    uint32_t memoryTypeIndex() const { return fMemoryTypeIndex; }
+    VkDeviceMemory memory() { return fAlloc; }
+
+    bool alloc(VkDeviceSize requestedSize, GrVkAlloc* alloc);
+    void free(const GrVkAlloc& alloc);
+
+private:
+    const GrVkGpu* fGpu;
+    uint32_t       fMemoryTypeIndex;
     VkDeviceMemory fAlloc;
-    FreeList       fFreeList;
+
+    typedef GrVkFreeListAlloc INHERITED;
 };
 
 class GrVkHeap {
 public:
     enum Strategy {
         kSubAlloc_Strategy,       // alloc large subheaps and suballoc within them
         kSingleAlloc_Strategy     // alloc/recycle an individual subheap per object
     };
 
     GrVkHeap(const GrVkGpu* gpu, Strategy strategy, VkDeviceSize subHeapSize)
         : fGpu(gpu)
         , fSubHeapSize(subHeapSize)
         , fAllocSize(0)
         , fUsedSize(0) {
         if (strategy == kSubAlloc_Strategy) {
             fAllocFunc = &GrVkHeap::subAlloc;
         } else {
             fAllocFunc = &GrVkHeap::singleAlloc;
         }
     }
 
-    ~GrVkHeap();
+    ~GrVkHeap() {}
 
     VkDeviceSize allocSize() const { return fAllocSize; }
     VkDeviceSize usedSize() const { return fUsedSize; }
 
     bool alloc(VkDeviceSize size, VkDeviceSize alignment, uint32_t memoryTypeIndex, 
                GrVkAlloc* alloc) {
         SkASSERT(size > 0);
         return (*this.*fAllocFunc)(size, alignment, memoryTypeIndex, alloc);
     }
     bool free(const GrVkAlloc& alloc);
 
 private:
     typedef bool (GrVkHeap::*AllocFunc)(VkDeviceSize size, VkDeviceSize alignment, 
                                         uint32_t memoryTypeIndex, GrVkAlloc* alloc);
 
     bool subAlloc(VkDeviceSize size, VkDeviceSize alignment, 
                   uint32_t memoryTypeIndex, GrVkAlloc* alloc);
     bool singleAlloc(VkDeviceSize size, VkDeviceSize alignment,
                      uint32_t memoryTypeIndex, GrVkAlloc* alloc);
 
     const GrVkGpu*         fGpu;
     VkDeviceSize           fSubHeapSize;
     VkDeviceSize           fAllocSize;
     VkDeviceSize           fUsedSize;
     AllocFunc              fAllocFunc;
     SkTArray<SkAutoTDelete<GrVkSubHeap>> fSubHeaps;
 };
 #endif