ui/gfx/gpu_memory_buffer.h

   1 // Copyright 2013 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 UI_GFX_GPU_MEMORY_BUFFER_H_
   6 #define UI_GFX_GPU_MEMORY_BUFFER_H_
   7
   8 #include "base/memory/shared_memory.h"
   9 #include "build/build_config.h"
  10 #include "ui/gfx/gfx_export.h"
  11
  12 #if defined(OS_ANDROID)
  13 #include <third_party/khronos/EGL/egl.h>
  14 #endif
  15
  16 namespace gfx {
  17
  18 enum GpuMemoryBufferType {
  19   EMPTY_BUFFER,
  20   SHARED_MEMORY_BUFFER,
  21   EGL_CLIENT_BUFFER,
  22   IO_SURFACE_BUFFER
  23 };
  24
  25 struct GpuMemoryBufferHandle {
  26   GpuMemoryBufferHandle()
  27       : type(EMPTY_BUFFER),
  28         handle(base::SharedMemory::NULLHandle())
  29 #if defined(OS_ANDROID)
  30         , native_buffer(NULL)
  31 #endif
  32 #if defined(OS_MACOSX)
  33         , io_surface_id(0)
  34 #endif
  35   {
  36   }
  37   bool is_null() const { return type == EMPTY_BUFFER; }
  38   GpuMemoryBufferType type;
  39   base::SharedMemoryHandle handle;
  40 #if defined(OS_ANDROID)
  41   EGLClientBuffer native_buffer;
  42 #endif
  43 #if defined(OS_MACOSX)
  44   uint32 io_surface_id;
  45 #endif
  46
  47 };
  48
  49 // Interface for creating and accessing a zero-copy GPU memory buffer.
  50 // This design evolved from the generalization of GraphicBuffer API
  51 // of Android framework.
  52 //
  53 // THREADING CONSIDERATIONS:
  54 //
  55 // This interface is thread-safe. However, multiple threads mapping
  56 // a buffer for Write or ReadOrWrite simultaneously may result in undefined
  57 // behavior and is not allowed.
  58 class GFX_EXPORT GpuMemoryBuffer {
  59  public:
  60   enum AccessMode {
  61     READ_ONLY,
  62     WRITE_ONLY,
  63     READ_WRITE,
  64   };
  65
  66   GpuMemoryBuffer();
  67   virtual ~GpuMemoryBuffer();
  68
  69   // Maps the buffer so the client can write the bitmap data in |*vaddr|
  70   // subsequently. This call may block, for instance if the hardware needs
  71   // to finish rendering or if CPU caches need to be synchronized.
  72   virtual void Map(AccessMode mode, void** vaddr) = 0;
  73
  74   // Unmaps the buffer. Called after all changes to the buffer are
  75   // completed.
  76   virtual void Unmap() = 0;
  77
  78   // Returns true iff the buffer is mapped.
  79   virtual bool IsMapped() const = 0;
  80
  81   // Returns the stride in bytes for the buffer.
  82   virtual uint32 GetStride() const = 0;
  83
  84   // Returns a platform specific handle for this buffer.
  85   virtual GpuMemoryBufferHandle GetHandle() const = 0;
  86 };
  87
  88 }  // namespace gfx
  89
  90 #endif  // UI_GFX_GPU_MEMORY_BUFFER_H_