gpu/command_buffer/common/buffer.h

   1 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef GPU_COMMAND_BUFFER_COMMON_BUFFER_H_
   6 #define GPU_COMMAND_BUFFER_COMMON_BUFFER_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/shared_memory.h"
  12 #include "gpu/gpu_export.h"
  13
  14 namespace base {
  15   class SharedMemory;
  16 }
  17
  18 namespace gpu {
  19
  20 class GPU_EXPORT BufferBacking {
  21  public:
  22   virtual ~BufferBacking() {}
  23   virtual void* GetMemory() const = 0;
  24   virtual size_t GetSize() const = 0;
  25 };
  26
  27 class GPU_EXPORT SharedMemoryBufferBacking : public BufferBacking {
  28  public:
  29   SharedMemoryBufferBacking(scoped_ptr<base::SharedMemory> shared_memory,
  30                             size_t size);
  31   ~SharedMemoryBufferBacking() override;
  32   void* GetMemory() const override;
  33   size_t GetSize() const override;
  34   base::SharedMemory* shared_memory() { return shared_memory_.get(); }
  35
  36  private:
  37   scoped_ptr<base::SharedMemory> shared_memory_;
  38   size_t size_;
  39   DISALLOW_COPY_AND_ASSIGN(SharedMemoryBufferBacking);
  40 };
  41
  42 // Buffer owns a piece of shared-memory of a certain size.
  43 class GPU_EXPORT Buffer : public base::RefCountedThreadSafe<Buffer> {
  44  public:
  45   explicit Buffer(scoped_ptr<BufferBacking> backing);
  46
  47   BufferBacking* backing() const { return backing_.get(); }
  48   void* memory() const { return memory_; }
  49   size_t size() const { return size_; }
  50
  51   // Returns NULL if the address overflows the memory.
  52   void* GetDataAddress(uint32 data_offset, uint32 data_size) const;
  53
  54  private:
  55   friend class base::RefCountedThreadSafe<Buffer>;
  56   ~Buffer();
  57
  58   scoped_ptr<BufferBacking> backing_;
  59   void* memory_;
  60   size_t size_;
  61
  62   DISALLOW_COPY_AND_ASSIGN(Buffer);
  63 };
  64
  65 static inline scoped_ptr<BufferBacking> MakeBackingFromSharedMemory(
  66     scoped_ptr<base::SharedMemory> shared_memory,
  67     size_t size) {
  68   return scoped_ptr<BufferBacking>(
  69       new SharedMemoryBufferBacking(shared_memory.Pass(), size));
  70 }
  71
  72 static inline scoped_refptr<Buffer> MakeBufferFromSharedMemory(
  73     scoped_ptr<base::SharedMemory> shared_memory,
  74     size_t size) {
  75   return new Buffer(MakeBackingFromSharedMemory(shared_memory.Pass(), size));
  76 }
  77
  78 }  // namespace gpu
  79
  80 #endif  // GPU_COMMAND_BUFFER_COMMON_BUFFER_H_