render_frame_proxy_host.h revision 5f1c94371a64b3196d4be9466099bb892df9b88e 
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  RenderFrameProxyHost(SiteInstance* site_instance,
59                       FrameTreeNode* frame_tree_node);
60  virtual ~RenderFrameProxyHost();
61
62  RenderProcessHost* GetProcess() {
63    return site_instance_->GetProcess();
64  }
65
66  // Initializes the object and creates the RenderFrameProxy in the process
67  // for the SiteInstance.
68  bool InitRenderFrameProxy();
69
70  int GetRoutingID() {
71    return routing_id_;
72  }
73
74  SiteInstance* GetSiteInstance() {
75    return site_instance_.get();
76  }
77
78  void SetChildRWHView(RenderWidgetHostView* view);
79
80  // TODO(nasko): The following methods should be removed once we don't have a
81  // swapped out state on RenderFrameHosts. See https://crbug.com/357747.
82  RenderFrameHostImpl* render_frame_host() {
83    return render_frame_host_.get();
84  }
85  RenderViewHostImpl* GetRenderViewHost();
86
87  void TakeFrameHostOwnership(
88      scoped_ptr<RenderFrameHostImpl> render_frame_host) {
89    render_frame_host_ = render_frame_host.Pass();
90  }
91  scoped_ptr<RenderFrameHostImpl> PassFrameHostOwnership();
92
93  // IPC::Sender
94  virtual bool Send(IPC::Message* msg) OVERRIDE;
95
96  // IPC::Listener
97  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
98
99  CrossProcessFrameConnector* cross_process_frame_connector() {
100    return cross_process_frame_connector_.get();
101  }
102
103 private:
104  // This RenderFrameProxyHost's routing id.
105  int routing_id_;
106
107  // The SiteInstance this proxy is associated with.
108  scoped_refptr<SiteInstance> site_instance_;
109
110  // The node in the frame tree where this proxy is located.
111  FrameTreeNode* frame_tree_node_;
112
113  // When a RenderFrameHost is in a different process from its parent in the
114  // frame tree, this class connects its associated RenderWidgetHostView
115  // to this RenderFrameProxyHost, which corresponds to the same frame in the
116  // parent's renderer process.
117  scoped_ptr<CrossProcessFrameConnector> cross_process_frame_connector_;
118
119  // TODO(nasko): This can be removed once we don't have a swapped out state on
120  // RenderFrameHosts. See https://crbug.com/357747.
121  scoped_ptr<RenderFrameHostImpl> render_frame_host_;
122
123  DISALLOW_COPY_AND_ASSIGN(RenderFrameProxyHost);
124};
125
126}  // namespace
127
128#endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_
129