Allow cmdbuffer creation from compositor thread.

content/renderer/gpu/gpu_channel_host.h

 // Copyright (c) 2011 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_RENDERER_GPU_GPU_CHANNEL_HOST_H_
 #define CONTENT_RENDERER_GPU_GPU_CHANNEL_HOST_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/hash_tables.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process_util.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/non_thread_safe.h"
 #include "content/common/gpu/gpu_info.h"
 #include "content/common/message_router.h"
 #include "content/renderer/gpu/gpu_video_decode_accelerator_host.h"
 #include "ipc/ipc_channel_handle.h"
+#include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 
 class CommandBufferProxy;
 class GpuSurfaceProxy;
 class GURL;
 class TransportTextureService;
 
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace IPC {
+class SyncMessageFilter;
+}
+
 // Encapsulates an IPC channel between the renderer and one plugin process.
 // On the plugin side there's a corresponding GpuChannel.
-class GpuChannelHost : public IPC::Channel::Listener,
-                       public IPC::Message::Sender,
+class GpuChannelHost : public IPC::Message::Sender,
                        public base::RefCountedThreadSafe<GpuChannelHost> {
  public:
   enum State {
     // Not yet connected.
     kUnconnected,
     // Ready to use.
     kConnected,
     // An error caused the host to become disconnected. Recreate channel to
     // reestablish connection.
     kLost
   };
 
   // Called on the render thread
   GpuChannelHost();
   virtual ~GpuChannelHost();
 
   // Connect to GPU process channel.
   void Connect(const IPC::ChannelHandle& channel_handle,
                base::ProcessHandle renderer_process_for_gpu);
 
   State state() const { return state_; }
 
   // Change state to kLost.
   void SetStateLost();
 
   // The GPU stats reported by the GPU process.
   void set_gpu_info(const GPUInfo& gpu_info);
   const GPUInfo& gpu_info() const;
 
-  // IPC::Channel::Listener implementation:
-  virtual bool OnMessageReceived(const IPC::Message& msg);
-  virtual void OnChannelConnected(int32 peer_pid);
-  virtual void OnChannelError();
+  void OnChannelError();
 
   // IPC::Message::Sender implementation:
   virtual bool Send(IPC::Message* msg);
 
   // Create and connect to a command buffer in the GPU process.
-  CommandBufferProxy* CreateViewCommandBuffer(
+  scoped_refptr<CommandBufferProxy> CreateViewCommandBuffer(
       int render_view_id,
       CommandBufferProxy* share_group,
       const std::string& allowed_extensions,
       const std::vector<int32>& attribs,
       const GURL& active_url);
 
   // Create and connect to a command buffer in the GPU process.
-  CommandBufferProxy* CreateOffscreenCommandBuffer(
+  scoped_refptr<CommandBufferProxy> CreateOffscreenCommandBuffer(
       const gfx::Size& size,
       CommandBufferProxy* share_group,
       const std::string& allowed_extensions,
       const std::vector<int32>& attribs,
       const GURL& active_url);
 
   // Creates a video decoder in the GPU process.
   // Returned pointer is owned by the CommandBufferProxy for |route_id|.
   GpuVideoDecodeAcceleratorHost* CreateVideoDecoder(
       int command_buffer_route_id,
       const std::vector<int32>& configs,
       media::VideoDecodeAccelerator::Client* client);
 
   // Destroy a command buffer created by this channel.
   void DestroyCommandBuffer(CommandBufferProxy* command_buffer);
 
   // Create a surface in the GPU process. Returns null on failure.
-  GpuSurfaceProxy* CreateOffscreenSurface(const gfx::Size& size);
+  scoped_refptr<GpuSurfaceProxy> CreateOffscreenSurface(const gfx::Size& size);
 
   // Destroy a surface in the GPU process.
   void DestroySurface(GpuSurfaceProxy* surface);
 
   TransportTextureService* transport_texture_service() {
     return transport_texture_service_.get();
   }
 
+  class MessageFilter : public IPC::ChannelProxy::MessageFilter,
+                        public base::NonThreadSafe {
+   public:
+    MessageFilter(GpuChannelHost* parent);
+
+    class Listener;
+    void AddRoute(int route_id,
+                  scoped_refptr<Listener> listener,
+                  base::MessageLoopProxy* loop);
+    void RemoveRoute(int route_id);
+
+    // IPC::ChannelProxy::MessageFilter implementation:
+    virtual bool OnMessageReceived(const IPC::Message& msg);
+    virtual void OnChannelError();
+
+    // An interface for working with cmdbuffer and surface proxies between
+    // threads.
+    class Listener : public base::RefCountedThreadSafe<Listener> {

[nduca, 2011/08/15 21:37:52]

Promote this class out of MessageFilter and as either GpuMessageHost::Listener,
or maybe even make it toplevel and call it GpuMessageListener?

+     public:
+      Listener();
+      virtual ~Listener();
+
+      virtual bool OnMessageReceived(const IPC::Message& msg) = 0;
+      virtual void OnChannelError() = 0;
+
+      // An orphaned listener is one whose parent context (might have) got
+      // deleted and which should ignore incoming messages. This flag is used
+      // to handle race conditions in between a context being deleted and
+      // the io thread referencing the proxy for message routing purposes.
+      void Orphan() { orphaned_ = true; }
+      bool IsOrphaned() { return orphaned_; }
+     private:
+      bool orphaned_;
+    };
+
+    private:
+     GpuChannelHost* parent_;
+
+     class ListenerInfo {

[nduca, 2011/08/15 21:37:52]

scoped_refptr<MessageLoopProxy> not MessageLoopProxy? Afact, the only point of
having a proxy is so that you can hold a reference to it and thus keep it alive.

Can we loop_ as a member of Listener? Set it during Listener::Listener(), that
way you dont have to have a second structure?

+      public:
+       ListenerInfo();
+       ListenerInfo(base::MessageLoopProxy* loop,
+                    scoped_refptr<Listener> listener);
+       virtual ~ListenerInfo();
+
+       base::MessageLoopProxy* loop_;
+       scoped_refptr<Listener> listener_;
+     };
+     typedef base::hash_map<int, ListenerInfo> ListenerMap;
+     ListenerMap listeners_;
+  };
+
  private:
+  // Add a route for the current message loop.
+  void AddRoute(int route_id, scoped_refptr<MessageFilter::Listener> listener);
+  void RemoveRoute(int route_id);
+
   State state_;
 
   GPUInfo gpu_info_;
 
   scoped_ptr<IPC::SyncChannel> channel_;
+  scoped_refptr<MessageFilter> channel_filter_;
 
-  // Used to implement message routing functionality to CommandBufferProxy
-  // objects
-  MessageRouter router_;
+  // Used to look up a proxy from its routing id.
+  typedef base::hash_map<int, scoped_refptr<CommandBufferProxy> > ProxyMap;
+  ProxyMap proxies_;
 
-  // Keep track of all the registered CommandBufferProxies to
-  // inform about OnChannelError
-  typedef base::hash_map<int, CommandBufferProxy*> ProxyMap;
-  ProxyMap proxies_;
+  // A lock to guard against concurrent access to members like the proxies map
+  // for calls from contexts that may live on the compositor or main thread.
+  mutable base::Lock context_lock_;
 
   // This is a MessageFilter to intercept IPC messages related to transport
   // textures. These messages are routed to TransportTextureHost.
   scoped_refptr<TransportTextureService> transport_texture_service_;
 
+  // A filter for sending messages from thread other than the main thread.
+  scoped_ptr<IPC::SyncMessageFilter> sync_filter_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuChannelHost);
 };
 
 #endif  // CONTENT_RENDERER_GPU_GPU_CHANNEL_HOST_H_