Revert "V4L2SVDA: Move allocation from GPU Child thread to decoder thread."

content/common/gpu/media/v4l2_slice_video_decode_accelerator.h

 // Copyright 2015 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_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_
 #define CONTENT_COMMON_GPU_MEDIA_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_
 
 #include <linux/videodev2.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 139 matching lines @@
   // Destroy output buffers and release associated resources (textures,
   // EGLImages). If |dismiss| is true, also dismissing the associated
   // PictureBuffers.
   bool DestroyOutputs(bool dismiss);
 
   // Used by DestroyOutputs.
   bool DestroyOutputBuffers();
 
   // Dismiss all |picture_buffer_ids| via Client::DismissPictureBuffer()
   // and signal |done| after finishing.
-  void DismissPictures(const std::vector<int32_t>& picture_buffer_ids,
+  void DismissPictures(std::vector<int32_t> picture_buffer_ids,
                        base::WaitableEvent* done);
 
   // Task to finish initialization on decoder_thread_.
   void InitializeTask();
 
   // Surface set change (resolution change) flow.
-  // If we have no surfaces allocated, start it immediately, otherwise mark
-  // ourselves as pending for surface set change.
+  // If we have no surfaces allocated, just allocate them and return.
+  // Otherwise mark us as pending for surface set change.
   void InitiateSurfaceSetChange();
   // If a surface set change is pending and we are ready, stop the device,
   // destroy outputs, releasing resources and dismissing pictures as required,
-  // followed by starting the flow to allocate a new set for the current
-  // resolution/DPB size, as provided by decoder.
-  bool FinishSurfaceSetChange();
+  // followed by allocating a new set for the new resolution/DPB size
+  // as provided by decoder. Finally, try to resume decoding.
+  void FinishSurfaceSetChangeIfNeeded();
 
   void NotifyError(Error error);
   void DestroyTask();
 
   // Sets the state to kError and notifies client if needed.
   void SetErrorState(Error error);
 
   // Flush flow when requested by client.
   // When Flush() is called, it posts a FlushTask, which checks the input queue.
   // If nothing is pending for decode on decoder_input_queue_, we call
   // InitiateFlush() directly. Otherwise, we push a dummy BitstreamBufferRef
   // onto the decoder_input_queue_ to schedule a flush. When we reach it later
   // on, we call InitiateFlush() to perform it at the correct time.
   void FlushTask();
   // Tell the decoder to flush all frames, reset it and mark us as scheduled
   // for flush, so that we can finish it once all pending decodes are finished.
   void InitiateFlush();
-  // To be called if decoder_flushing_ is true. If not all pending frames are
-  // decoded, return false, requesting the caller to try again later.
-  // Otherwise perform flush by sending all pending pictures to the client,
-  // notify it that flush is finished and return true, informing the caller
-  // that further progress can be made.
-  bool FinishFlush();
+  // If all pending frames are decoded and we are waiting to flush, perform it.
+  // This will send all pending pictures to client and notify the client that
+  // flush is complete and puts us in a state ready to resume.
+  void FinishFlushIfNeeded();
 
   // Reset flow when requested by client.
-  // Drop all inputs, reset the decoder and mark us as pending for reset.
+  // Drop all inputs and reset the decoder and mark us as pending for reset.
   void ResetTask();
-  // To be called if decoder_resetting_ is true. If not all pending frames are
-  // decoded, return false, requesting the caller to try again later.
-  // Otherwise perform reset by dropping all pending outputs (client is not
-  // interested anymore), notifying it that reset is finished, and return true,
-  // informing the caller that further progress can be made.
-  bool FinishReset();
+  // If all pending frames are decoded and we are waiting to reset, perform it.
+  // This drops all pending outputs (client is not interested anymore),
+  // notifies the client we are done and puts us in a state ready to resume.
+  void FinishResetIfNeeded();
 
-  // Allocate V4L2 buffers and assign them to |buffers| provided by the client
-  // via AssignPictureBuffers() on decoder thread.
-  void AssignPictureBuffersTask(
-    const std::vector<media::PictureBuffer>& buffers);
-
-  // Create EGLImages bound to textures in |buffers| for given
-  // |output_format_fourcc| and |output_planes_count|.
-  void CreateEGLImages(const std::vector<media::PictureBuffer>& buffers,
-                       uint32_t output_format_fourcc,
-                       size_t output_planes_count);
-
-  // Assign |egl_images| to previously-allocated V4L2 buffers in
-  // output_buffer_map_ and picture ids from |buffers| and finish the surface
-  // change sequence.
-  void AssignEGLImages(const std::vector<media::PictureBuffer>& buffers,
-                       const std::vector<EGLImageKHR>& egl_images);
-
-  // Process pending events, if any.
+  // Process pending events if any.
   void ProcessPendingEventsIfNeeded();
 
   // Performed on decoder_thread_ as a consequence of poll() on decoder_thread_
   // returning an event.
   void ServiceDeviceTask();
 
   // Schedule poll if we have any buffers queued and the poll thread
   // is not stopped (on surface set change).
   void SchedulePollIfNeeded();
 
@@ skipping 156 matching lines @@
   V4L2DecodeSurfaceByPictureBufferId surfaces_at_display_;
 
   // Record for decoded pictures that can be sent to PictureReady.
   struct PictureRecord;
   // Pictures that are ready but not sent to PictureReady yet.
   std::queue<PictureRecord> pending_picture_ready_;
 
   // The number of pictures that are sent to PictureReady and will be cleared.
   int picture_clearing_count_;
 
+  // Used by the decoder thread to wait for AssignPictureBuffers to arrive
+  // to avoid races with potential Reset requests.
+  base::WaitableEvent pictures_assigned_;
+
   // EGL state
   EGLDisplay egl_display_;
 
   // Callback to get current GLContext.
   GetGLContextCallback get_gl_context_cb_;
   // Callback to set the correct gl context.
   MakeGLContextCurrentCallback make_context_current_cb_;
 
   // The WeakPtrFactory for |weak_this_|.
   base::WeakPtrFactory<V4L2SliceVideoDecodeAccelerator> weak_this_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(V4L2SliceVideoDecodeAccelerator);
 };
 
 class V4L2H264Picture;
 class V4L2VP8Picture;
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_MEDIA_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_