Use InterlockedAdd(0) to get the current state in DXVAVideoDecodeAccelerator::GetState

content/common/gpu/media/dxva_video_decode_accelerator.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_COMMON_GPU_MEDIA_DXVA_VIDEO_DECODE_ACCELERATOR_H_
 #define CONTENT_COMMON_GPU_MEDIA_DXVA_VIDEO_DECODE_ACCELERATOR_H_
 
 #include <d3d9.h>
 // Work around bug in this header by disabling the relevant warning for it.
 // https://connect.microsoft.com/VisualStudio/feedback/details/911260/dxva2api-h-in-win8-sdk-triggers-c4201-with-w4
@@ skipping 149 matching lines @@
 
   // Called after the client indicates we can recycle a stale picture buffer.
   void DeferredDismissStaleBuffer(int32 picture_buffer_id);
 
   // Sets the state of the decoder. Called from the main thread and the decoder
   // thread. The state is changed on the main thread.
   void SetState(State state);
 
   // Gets the state of the decoder. Can be called from the main thread and
   // the decoder thread. Thread safe.
-  State GetState() const;
+  State GetState();
 
   // Worker function for the Decoder Reset functionality. Executes on the
   // decoder thread and queues tasks on the main thread as needed.
   void ResetHelper();
 
   // Starts the thread used for decoding.
   void StartDecoderThread();
 
   // Returns if we have output samples waiting to be processed. We only
   // allow one output sample to be present in the output queue at any given
@@ skipping 36 matching lines @@
   // creating the device manager. However it seems that the device manager
   // holds onto the token and attempts to access it if the underlying device
   // changes.
   // TODO(ananta): This needs to be verified.
   uint32 dev_manager_reset_token_;
 
   // The EGL config to use for decoded frames.
   EGLConfig egl_config_;
 
   // Current state of the decoder.
-  State state_;
+  volatile State state_;
 
   MFT_INPUT_STREAM_INFO input_stream_info_;
   MFT_OUTPUT_STREAM_INFO output_stream_info_;
 
   // Contains information about a decoded sample.
   struct PendingSampleInfo {
     PendingSampleInfo(int32 buffer_id, IMFSample* sample);
     ~PendingSampleInfo();
 
     int32 input_buffer_id;
@@ skipping 62 matching lines @@
   const base::WeakPtr<DXVAVideoDecodeAccelerator> weak_ptr_;
 
   // Set to true if we are in the context of a Flush operation. Used to prevent
   // multiple flush done notifications being sent out.
   bool pending_flush_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_MEDIA_DXVA_VIDEO_DECODE_ACCELERATOR_H_