content/browser/gpu/gpu_surface_tracker.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 CONTENT_BROWSER_GPU_GPU_SURFACE_TRACKER_H_
#define CONTENT_BROWSER_GPU_GPU_SURFACE_TRACKER_H_

#include <stddef.h>

#include <map>

#include "base/macros.h"
#include "base/memory/singleton.h"
#include "base/synchronization/lock.h"
#include "content/common/content_export.h"
#include "gpu/ipc/common/gpu_surface_lookup.h"
#include "gpu/ipc/common/surface_handle.h"
#include "ui/gfx/native_widget_types.h"

namespace content {

// This class is used on Android and Mac, and is responsible for tracking native
// window surfaces exposed to the GPU process. Every surface gets registered to
// this class, and gets a handle.  The handle can be passed to
// CommandBufferProxyImpl::Create or to
// GpuMemoryBufferManager::AllocateGpuMemoryBuffer.
// On Android, the handle is used in the GPU process to get a reference to the
// ANativeWindow, using GpuSurfaceLookup (implemented by
// SurfaceTextureManagerImpl).
// On Mac, the handle just passes through the GPU process, and is sent back via
// GpuCommandBufferMsg_SwapBuffersCompleted to reference the surface.
// This class is thread safe.
class CONTENT_EXPORT GpuSurfaceTracker : public gpu::GpuSurfaceLookup {
 public:
  // GpuSurfaceLookup implementation:
  // Returns the native widget associated with a given surface_handle.
  // On Android, this adds a reference on the ANativeWindow.
  gfx::AcceleratedWidget AcquireNativeWidget(
      gpu::SurfaceHandle surface_handle) override;

#if defined(OS_ANDROID)
  gl::ScopedJavaSurface AcquireJavaSurface(int surface_id) override;
#endif

  // Gets the global instance of the surface tracker.
  static GpuSurfaceTracker* Get() { return GetInstance(); }

  // Adds a surface for a native widget. Returns the surface ID.
  int AddSurfaceForNativeWidget(gfx::AcceleratedWidget widget);

  // Return true if the surface handle is registered with the tracker.
  bool IsValidSurfaceHandle(gpu::SurfaceHandle surface_handle) const;

  // Removes a given existing surface.
  void RemoveSurface(gpu::SurfaceHandle surface_handle);

  // Returns the number of surfaces currently registered with the tracker.
  std::size_t GetSurfaceCount();

  // Gets the global instance of the surface tracker. Identical to Get(), but
  // named that way for the implementation of Singleton.
  static GpuSurfaceTracker* GetInstance();

 private:
  typedef std::map<gpu::SurfaceHandle, gfx::AcceleratedWidget> SurfaceMap;

  friend struct base::DefaultSingletonTraits<GpuSurfaceTracker>;

  GpuSurfaceTracker();
  ~GpuSurfaceTracker() override;

  base::Lock lock_;
  SurfaceMap surface_map_;
  int next_surface_handle_;

  DISALLOW_COPY_AND_ASSIGN(GpuSurfaceTracker);
};

}  // namespace content

#endif  // CONTENT_BROWSER_GPU_GPU_SURFACE_TRACKER_H_