render_frame_proxy_host.h revision 1320f92c476a1ad9d19dba2a48c72b75566198e9 
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
14namespace content {
15
16class CrossProcessFrameConnector;
17class FrameTreeNode;
18class RenderProcessHost;
19class RenderFrameHostImpl;
20class RenderViewHostImpl;
21class 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.
54class RenderFrameProxyHost
55    : public IPC::Listener,
56      public IPC::Sender {
57 public:
58  static RenderFrameProxyHost* FromID(int process_id, int routing_id);
59
60  RenderFrameProxyHost(SiteInstance* site_instance,
61                       FrameTreeNode* frame_tree_node);
62  virtual ~RenderFrameProxyHost();
63
64  RenderProcessHost* GetProcess() {
65    return site_instance_->GetProcess();
66  }
67
68  // Initializes the object and creates the RenderFrameProxy in the process
69  // for the SiteInstance.
70  bool InitRenderFrameProxy();
71
72  int GetRoutingID() {
73    return routing_id_;
74  }
75
76  SiteInstance* GetSiteInstance() {
77    return site_instance_.get();
78  }
79
80  FrameTreeNode* frame_tree_node() const { return frame_tree_node_; };
81
82  void SetChildRWHView(RenderWidgetHostView* view);
83
84  // TODO(nasko): The following methods should be removed once we don't have a
85  // swapped out state on RenderFrameHosts. See https://crbug.com/357747.
86  RenderFrameHostImpl* render_frame_host() {
87    return render_frame_host_.get();
88  }
89  RenderViewHostImpl* GetRenderViewHost();
90
91  void TakeFrameHostOwnership(
92      scoped_ptr<RenderFrameHostImpl> render_frame_host) {
93    render_frame_host_ = render_frame_host.Pass();
94  }
95  scoped_ptr<RenderFrameHostImpl> PassFrameHostOwnership();
96
97  // IPC::Sender
98  virtual bool Send(IPC::Message* msg) OVERRIDE;
99
100  // IPC::Listener
101  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
102
103  CrossProcessFrameConnector* cross_process_frame_connector() {
104    return cross_process_frame_connector_.get();
105  }
106
107  // Set the frame's opener to null in the renderer process in response to an
108  // action in another renderer process.
109  void DisownOpener();
110
111 private:
112  // This RenderFrameProxyHost's routing id.
113  int routing_id_;
114
115  // The SiteInstance this proxy is associated with.
116  scoped_refptr<SiteInstance> site_instance_;
117
118  // The node in the frame tree where this proxy is located.
119  FrameTreeNode* frame_tree_node_;
120
121  // When a RenderFrameHost is in a different process from its parent in the
122  // frame tree, this class connects its associated RenderWidgetHostView
123  // to this RenderFrameProxyHost, which corresponds to the same frame in the
124  // parent's renderer process.
125  scoped_ptr<CrossProcessFrameConnector> cross_process_frame_connector_;
126
127  // TODO(nasko): This can be removed once we don't have a swapped out state on
128  // RenderFrameHosts. See https://crbug.com/357747.
129  scoped_ptr<RenderFrameHostImpl> render_frame_host_;
130
131  DISALLOW_COPY_AND_ASSIGN(RenderFrameProxyHost);
132};
133
134}  // namespace
135
136#endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_
137