1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_ 6 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_ 7 8 #include "base/memory/scoped_ptr.h" 9 #include "content/browser/frame_host/render_frame_host_impl.h" 10 #include "content/browser/site_instance_impl.h" 11 #include "ipc/ipc_listener.h" 12 #include "ipc/ipc_sender.h" 13 14 namespace content { 15 16 class CrossProcessFrameConnector; 17 class FrameTreeNode; 18 class RenderProcessHost; 19 class RenderFrameHostImpl; 20 class RenderViewHostImpl; 21 class RenderWidgetHostView; 22 23 // When a page's frames are rendered by multiple processes, each renderer has a 24 // full copy of the frame tree. It has full RenderFrames for the frames it is 25 // responsible for rendering and placeholder objects (i.e., RenderFrameProxies) 26 // for frames rendered by other processes. 27 // 28 // This class is the browser-side host object for the placeholder. Each node in 29 // the frame tree has a RenderFrameHost for the active SiteInstance and a set 30 // of RenderFrameProxyHost objects - one for all other SiteInstances with 31 // references to this frame. The proxies allow us to keep existing window 32 // references valid over cross-process navigations and route cross-site 33 // asynchronous JavaScript calls, such as postMessage. 34 // 35 // For now, RenderFrameProxyHost is created when a RenderFrameHost is swapped 36 // out and acts just as a wrapper. It is destroyed when the RenderFrameHost is 37 // swapped back in or is no longer referenced and is therefore deleted. 38 // 39 // Long term, RenderFrameProxyHost will be created whenever a cross-site 40 // navigation occurs and a reference to the frame navigating needs to be kept 41 // alive. A RenderFrameProxyHost and a RenderFrameHost for the same SiteInstance 42 // can exist at the same time, but only one will be "active" at a time. 43 // There are two cases where the two objects will coexist: 44 // * When navigating cross-process and there is already a RenderFrameProxyHost 45 // for the new SiteInstance. A pending RenderFrameHost is created, but it is 46 // not used until it commits. At that point, RenderFrameHostManager transitions 47 // the pending RenderFrameHost to the active one and deletes the proxy. 48 // * When navigating cross-process and the existing document has an unload 49 // event handler. When the new navigation commits, RenderFrameHostManager 50 // creates a RenderFrameProxyHost for the old SiteInstance and uses it going 51 // forward. It also instructs the RenderFrameHost to run the unload event 52 // handler and is kept alive for the duration. Once the event handling is 53 // complete, the RenderFrameHost is deleted. 54 class RenderFrameProxyHost 55 : public IPC::Listener, 56 public IPC::Sender { 57 public: 58 RenderFrameProxyHost(SiteInstance* site_instance, 59 FrameTreeNode* frame_tree_node); 60 virtual ~RenderFrameProxyHost(); 61 62 RenderProcessHost* GetProcess() { 63 return site_instance_->GetProcess(); 64 } 65 66 int GetRoutingID() { 67 return routing_id_; 68 } 69 70 SiteInstance* GetSiteInstance() { 71 return site_instance_.get(); 72 } 73 74 void SetChildRWHView(RenderWidgetHostView* view); 75 76 // TODO(nasko): The following methods should be removed once we don't have a 77 // swapped out state on RenderFrameHosts. See https://crbug.com/357747. 78 RenderFrameHostImpl* render_frame_host() { 79 return render_frame_host_.get(); 80 } 81 RenderViewHostImpl* GetRenderViewHost(); 82 83 void TakeFrameHostOwnership( 84 scoped_ptr<RenderFrameHostImpl> render_frame_host) { 85 render_frame_host_ = render_frame_host.Pass(); 86 } 87 scoped_ptr<RenderFrameHostImpl> PassFrameHostOwnership(); 88 89 // IPC::Sender 90 virtual bool Send(IPC::Message* msg) OVERRIDE; 91 92 // IPC::Listener 93 virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE; 94 95 CrossProcessFrameConnector* cross_process_frame_connector() { 96 return cross_process_frame_connector_.get(); 97 } 98 99 private: 100 // This RenderFrameProxyHost's routing id. 101 int routing_id_; 102 103 // The SiteInstance this proxy is associated with. 104 scoped_refptr<SiteInstance> site_instance_; 105 106 // The node in the frame tree where this proxy is located. 107 FrameTreeNode* frame_tree_node_; 108 109 // When a RenderFrameHost is in a different process from its parent in the 110 // frame tree, this class connects its associated RenderWidgetHostView 111 // to this RenderFrameProxyHost, which corresponds to the same frame in the 112 // parent's renderer process. 113 scoped_ptr<CrossProcessFrameConnector> cross_process_frame_connector_; 114 115 // TODO(nasko): This can be removed once we don't have a swapped out state on 116 // RenderFrameHosts. See https://crbug.com/357747. 117 scoped_ptr<RenderFrameHostImpl> render_frame_host_; 118 119 DISALLOW_COPY_AND_ASSIGN(RenderFrameProxyHost); 120 }; 121 122 } // namespace 123 124 #endif // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_ 125