gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/mapped_memory.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_
 #define GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_
 
 #include "base/memory/scoped_vector.h"
 #include "gpu/command_buffer/client/fenced_allocator.h"
 #include "gpu/command_buffer/common/buffer.h"
 #include "gpu/command_buffer/common/types.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
 
 class CommandBufferHelper;
 
 // Manages a shared memory segment.
 class GPU_EXPORT MemoryChunk {
  public:
-  MemoryChunk(int32 shm_id, gpu::Buffer shm, CommandBufferHelper* helper);
+  MemoryChunk(int32 shm_id,
+              gpu::Buffer shm,
+              bool aggressive_reuse,
+              CommandBufferHelper* helper);
 
   // Gets the size of the largest free block that is available without waiting.
   unsigned int GetLargestFreeSizeWithoutWaiting() {
     return allocator_.GetLargestFreeSize();
   }
 
   // Gets the size of the largest free block that can be allocated if the
   // caller can wait.
   unsigned int GetLargestFreeSizeWithWaiting() {
     return allocator_.GetLargestFreeOrPendingSize();
@@ skipping 68 matching lines @@
   }
 
  private:
   int32 shm_id_;
   gpu::Buffer shm_;
   FencedAllocatorWrapper allocator_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryChunk);
 };
 
+// Configure MappedMemoryManager
+struct GPU_EXPORT MappedMemoryManagerSettings {
+  // |unused_memory_reclaim_limit|: When exceeded this causes pending memory
+  // to be reclaimed before allocating more memory.
+  size_t unused_memory_reclaim_limit;
+
+  // |aggressive_reuse|: When set to true, the memory manager will reuse a
+  // block marked either as FREE or FREE_PENDING_TOKEN. This setting is only
+  // allowed if the user can guarantee that all parts are done using a block
+  // that was free:ed by the client.
+  bool aggressive_reuse;
+};
+
 // Manages MemoryChunks.
 class GPU_EXPORT MappedMemoryManager {
  public:
   enum MemoryLimit {
     kNoLimit = 0,
   };
 
-  // |unused_memory_reclaim_limit|: When exceeded this causes pending memory
-  // to be reclaimed before allocating more memory.
   MappedMemoryManager(CommandBufferHelper* helper,
-                      size_t unused_memory_reclaim_limit);
+                      MappedMemoryManagerSettings settings);
 
   ~MappedMemoryManager();
 
   unsigned int chunk_size_multiple() const {
     return chunk_size_multiple_;
   }
 
   void set_chunk_size_multiple(unsigned int multiple) {
     chunk_size_multiple_ = multiple;
   }
@@ skipping 37 matching lines @@
 
  private:
   typedef ScopedVector<MemoryChunk> MemoryChunkVector;
 
   // size a chunk is rounded up to.
   unsigned int chunk_size_multiple_;
   CommandBufferHelper* helper_;
   MemoryChunkVector chunks_;
   size_t allocated_memory_;
   size_t max_free_bytes_;
+  bool aggressive_reuse_;
 
   DISALLOW_COPY_AND_ASSIGN(MappedMemoryManager);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_