Make RendererGpuVideoDecoderFactories live on arbitrary threads.

media/filters/gpu_video_decoder.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 MEDIA_FILTERS_GPU_VIDEO_DECODER_H_
 #define MEDIA_FILTERS_GPU_VIDEO_DECODER_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 10 matching lines @@
 namespace base {
 class MessageLoopProxy;
 class SharedMemory;
 }
 
 class SkBitmap;
 
 namespace media {
 
 class DecoderBuffer;
-class VDAClientProxy;
 
 // GPU-accelerated video decoder implementation.  Relies on
 // AcceleratedVideoDecoderMsg_Decode and friends.
-// All methods internally trampoline to the |message_loop| passed to the ctor.
 class MEDIA_EXPORT GpuVideoDecoder
     : public VideoDecoder,
       public VideoDecodeAccelerator::Client {
  public:
   // Helper interface for specifying factories needed to instantiate a
   // GpuVideoDecoder.
+  // TODO(wuchengli): move this out of GpuVideoDecoder because RTCVideoDecoder

[Ami GONE FROM CHROMIUM, 2013/07/22 19:46:21]

Rebase makes this unnecessary?

[wuchengli, 2013/07/23 16:29:28]

I couldn't submit that CL today because of submit try bots failures. Some other
people were blocked by the same failure. I'll rebase my CL as soon as it is
submitted.

+  // also uses this.
   class MEDIA_EXPORT Factories : public base::RefCountedThreadSafe<Factories> {
    public:
     // Caller owns returned pointer.
     virtual VideoDecodeAccelerator* CreateVideoDecodeAccelerator(
         VideoCodecProfile, VideoDecodeAccelerator::Client*) = 0;
 
     // Allocate & delete native textures.
     virtual uint32 CreateTextures(int32 count, const gfx::Size& size,
                                   std::vector<uint32>* texture_ids,
                                   std::vector<gpu::Mailbox>* texture_mailboxes,
@@ skipping 13 matching lines @@
     // Returns the message loop the VideoDecodeAccelerator runs on.
     virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() = 0;
 
     // Abort any outstanding factory operations and error any future
     // attempts at factory operations
     virtual void Abort() = 0;
 
     // Returns true if Abort() has been called.
     virtual bool IsAborted() = 0;
 
+    // Makes a copy of |this|.
+    virtual scoped_refptr<Factories> Clone() = 0;
+
    protected:
     friend class base::RefCountedThreadSafe<Factories>;
     virtual ~Factories();
   };
 
+  // |message_loop| should be the same as the one running |factories|.

[Ami GONE FROM CHROMIUM, 2013/07/22 19:46:21]

Why not drop this param and just use factories->GetMessageLoop().get() instead?

[wuchengli, 2013/07/23 16:29:28]

That was recommended by Andrew.
https://codereview.chromium.org/19534002/diff/2002/media/filters/gpu_video_de...

Andrew. I've changed this back. First I feel using the message loop of
|factories| is natural because it is the "factory" of the video decoder. Also we
can remove DCHECKs and the lines of code are less. Second those
DCHECK(gvd_loop_proxy_->BelongsToCurrentThread()) in GpuVideoDecoder methods
will still require |factories| must have been created to work on the media
message loop.

   GpuVideoDecoder(const scoped_refptr<base::MessageLoopProxy>& message_loop,
                   const scoped_refptr<Factories>& factories);
 
   // VideoDecoder implementation.
   virtual void Initialize(const VideoDecoderConfig& config,
                           const PipelineStatusCB& status_cb) OVERRIDE;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const ReadCB& read_cb) OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop(const base::Closure& closure) OVERRIDE;
@@ skipping 36 matching lines @@
       const scoped_refptr<VideoFrame>& frame);
 
   // Indicate the picture buffer can be reused by the decoder.
   void ReusePictureBuffer(int64 picture_buffer_id, uint32 sync_point);
 
   void RecordBufferData(
       const BitstreamBuffer& bitstream_buffer, const DecoderBuffer& buffer);
   void GetBufferData(int32 id, base::TimeDelta* timetamp,
                      gfx::Rect* visible_rect, gfx::Size* natural_size);
 
-  // Sets |vda_| and |weak_vda_| on the GVD thread and runs |status_cb|.
-  void SetVDA(const PipelineStatusCB& status_cb,
-              VideoDecodeAccelerator* vda,
-              base::WeakPtr<VideoDecodeAccelerator> weak_vda);
-
-  // Call VDA::Destroy() on |vda_loop_proxy_| ensuring that |this| outlives the
-  // Destroy() call.
   void DestroyVDA();
 
   // A shared memory segment and its allocated size.
   struct SHMBuffer {
     SHMBuffer(base::SharedMemory* m, size_t s);
     ~SHMBuffer();
     base::SharedMemory* shm;
     size_t size;
   };
 
   // Request a shared-memory segment of at least |min_size| bytes.  Will
   // allocate as necessary.  Caller does not own returned pointer.
   SHMBuffer* GetSHM(size_t min_size);
 
   // Return a shared-memory segment to the available pool.
   void PutSHM(SHMBuffer* shm_buffer);
 
   void DestroyTextures();
 
   bool needs_bitstream_conversion_;
 
-  // Message loop on which to fire callbacks and trampoline calls to this class
-  // if they arrive on other loops.
+  // Message loop which this class and |factories_| run on.
   scoped_refptr<base::MessageLoopProxy> gvd_loop_proxy_;
   base::WeakPtrFactory<GpuVideoDecoder> weak_factory_;
   base::WeakPtr<GpuVideoDecoder> weak_this_;
 
-  // Message loop on which to makes all calls to vda_.  (beware this loop may be
-  // paused during the Pause/Flush/Stop dance PipelineImpl::Stop() goes
-  // through).
-  scoped_refptr<base::MessageLoopProxy> vda_loop_proxy_;
-
   scoped_refptr<Factories> factories_;
 
-  // Proxies calls from |vda_| to |gvd_loop_proxy_| and used to safely detach
-  // during shutdown.
-  scoped_refptr<VDAClientProxy> client_proxy_;
-
-  // Populated during Initialize() via SetVDA() (on success) and unchanged
-  // until an error occurs.
+  // Populated during Initialize() (on success) and unchanged until an error
+  // occurs.
   scoped_ptr<VideoDecodeAccelerator> vda_;
-  // Used to post tasks from the GVD thread to the VDA thread safely.
-  base::WeakPtr<VideoDecodeAccelerator> weak_vda_;
 
   // Callbacks that are !is_null() only during their respective operation being
   // asynchronously executed.
   ReadCB pending_read_cb_;
   base::Closure pending_reset_cb_;
 
   State state_;
 
   VideoDecoderConfig config_;
 
@@ skipping 43 matching lines @@
   // Set during ProvidePictureBuffers(), used for checking and implementing
   // HasAvailableOutputFrames().
   int available_pictures_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_GPU_VIDEO_DECODER_H_