gecko-dev/gfx/layers/d3d11/ReadbackManagerD3D11.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef GFX_READBACKMANAGERD3D11_H
#define GFX_READBACKMANAGERD3D11_H
#include <windows.h>
#include <d3d10_1.h>
#include "mozilla/UniquePtr.h"
#include "nsTArray.h"
namespace mozilla {
namespace layers {
class TextureReadbackSink;
struct ReadbackTask;
class ReadbackManagerD3D11 final {
NS_INLINE_DECL_REFCOUNTING(ReadbackManagerD3D11)
public:
ReadbackManagerD3D11();
/**
* Tell the readback manager to post a readback task.
*
* @param aTexture D3D10_USAGE_STAGING texture that will contain the data that
* was readback.
* @param aSink TextureReadbackSink that the resulting DataSourceSurface
* should be dispatched to.
*/
void PostTask(ID3D10Texture2D* aTexture, TextureReadbackSink* aSink);
private:
~ReadbackManagerD3D11();
static DWORD WINAPI StartTaskThread(void* aManager);
void ProcessTasks();
// The invariant maintained by |mTaskSemaphore| is that the readback thread
// will awaken from WaitForMultipleObjects() at least once per readback
// task enqueued by the main thread. Since the readback thread processes
// exactly one task per wakeup (with one exception), no tasks are lost. The
// exception is when the readback thread is shut down, which orphans the
// remaining tasks, on purpose.
HANDLE mTaskSemaphore;
// Event signaled when the task thread should shutdown
HANDLE mShutdownEvent;
// Handle to the task thread
HANDLE mTaskThread;
// FiFo list of readback tasks that are to be executed. Access is synchronized
// by mTaskMutex.
CRITICAL_SECTION mTaskMutex;
nsTArray<UniquePtr<ReadbackTask>> mPendingReadbackTasks;
};
} // namespace layers
} // namespace mozilla
#endif /* GFX_READBACKMANAGERD3D11_H */