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1 // Copyright 2013 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_CHILD_NPAPI_NP_CHANNEL_BASE_H_ | |
6 #define CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_ | |
7 | |
8 #include <stdint.h> | |
9 | |
10 #include <string> | |
11 | |
12 #include "base/containers/hash_tables.h" | |
13 #include "base/macros.h" | |
14 #include "base/memory/ref_counted.h" | |
15 #include "base/memory/scoped_ptr.h" | |
16 #include "base/process/process.h" | |
17 #include "ipc/ipc_channel_handle.h" | |
18 #include "ipc/ipc_sync_channel.h" | |
19 #include "ipc/message_router.h" | |
20 | |
21 namespace base { | |
22 class SingleThreadTaskRunner; | |
23 } | |
24 | |
25 namespace content { | |
26 | |
27 // Encapsulates an IPC channel between a renderer and another process. Used to | |
28 // proxy access to NP objects. | |
29 class NPChannelBase : public IPC::Listener, | |
30 public IPC::Sender, | |
31 public base::RefCountedThreadSafe<NPChannelBase> { | |
32 public: | |
33 // WebPlugin[Delegate] call these on construction and destruction to setup | |
34 // the routing and manage lifetime of this object. | |
35 void AddRoute(int route_id, IPC::Listener* listener); | |
36 void RemoveRoute(int route_id); | |
37 | |
38 // IPC::Sender implementation: | |
39 bool Send(IPC::Message* msg) override; | |
40 | |
41 base::ProcessId peer_pid() { return channel_->GetPeerPID(); } | |
42 IPC::ChannelHandle channel_handle() const { return channel_handle_; } | |
43 | |
44 // Returns a new route id. | |
45 virtual int GenerateRouteID() = 0; | |
46 | |
47 // Returns whether the channel is valid or not. A channel is invalid | |
48 // if it is disconnected due to a channel error. | |
49 bool channel_valid() { | |
50 return channel_valid_; | |
51 } | |
52 | |
53 // Returns the most recent NPChannelBase to have received a message | |
54 // in this process. | |
55 static NPChannelBase* GetCurrentChannel(); | |
56 | |
57 static void CleanupChannels(); | |
58 | |
59 // Returns the event that's set when a call to the renderer causes a modal | |
60 // dialog to come up. The default implementation returns NULL. Derived | |
61 // classes should override this method if this functionality is required. | |
62 virtual base::WaitableEvent* GetModalDialogEvent(int render_view_id); | |
63 | |
64 protected: | |
65 typedef NPChannelBase* (*ChannelFactory)(); | |
66 | |
67 friend class base::RefCountedThreadSafe<NPChannelBase>; | |
68 | |
69 ~NPChannelBase() override; | |
70 | |
71 // Returns a NPChannelBase derived object for the given channel name. | |
72 // If an existing channel exists returns that object, otherwise creates a | |
73 // new one. Even though on creation the object is refcounted, each caller | |
74 // must still ref count the returned value. When there are no more routes | |
75 // on the channel and its ref count is 0, the object deletes itself. | |
76 static NPChannelBase* GetChannel( | |
77 const IPC::ChannelHandle& channel_handle, | |
78 IPC::Channel::Mode mode, | |
79 ChannelFactory factory, | |
80 base::SingleThreadTaskRunner* ipc_task_runner, | |
81 bool create_pipe_now, | |
82 base::WaitableEvent* shutdown_event); | |
83 | |
84 // Sends a message to all instances. | |
85 static void Broadcast(IPC::Message* message); | |
86 | |
87 // Called on the worker thread | |
88 NPChannelBase(); | |
89 | |
90 virtual void CleanUp() { } | |
91 | |
92 // Implemented by derived classes to handle control messages | |
93 virtual bool OnControlMessageReceived(const IPC::Message& msg); | |
94 | |
95 // IPC::Listener implementation: | |
96 bool OnMessageReceived(const IPC::Message& msg) override; | |
97 void OnChannelConnected(int32_t peer_pid) override; | |
98 void OnChannelError() override; | |
99 | |
100 void set_send_unblocking_only_during_unblock_dispatch() { | |
101 send_unblocking_only_during_unblock_dispatch_ = true; | |
102 } | |
103 | |
104 virtual bool Init(base::SingleThreadTaskRunner* ipc_task_runner, | |
105 bool create_pipe_now, | |
106 base::WaitableEvent* shutdown_event); | |
107 | |
108 scoped_ptr<IPC::SyncChannel> channel_; | |
109 IPC::ChannelHandle channel_handle_; | |
110 | |
111 private: | |
112 IPC::Channel::Mode mode_; | |
113 // This tracks the number of routes registered without an NPObject. It's used | |
114 // to manage the lifetime of this object. See comment for AddRoute() and | |
115 // RemoveRoute(). | |
116 int non_npobject_count_; | |
117 int peer_pid_; | |
118 | |
119 // true when in the middle of a RemoveRoute call | |
120 bool in_remove_route_; | |
121 | |
122 // Used to implement message routing functionality to WebPlugin[Delegate] | |
123 // objects | |
124 IPC::MessageRouter router_; | |
125 | |
126 // A channel is invalid if it is disconnected as a result of a channel | |
127 // error. This flag is used to indicate the same. | |
128 bool channel_valid_; | |
129 | |
130 // Track whether we're dispatching a message with the unblock flag; works like | |
131 // a refcount, 0 when we're not. | |
132 int in_unblock_dispatch_; | |
133 | |
134 // If true, sync messages will only be marked as unblocking if the channel is | |
135 // in the middle of dispatching an unblocking message. The non-renderer | |
136 // process wants to avoid setting the unblock flag on its sync messages | |
137 // unless necessary, since it can potentially introduce reentrancy into | |
138 // WebKit in ways that it doesn't expect (i.e. causing layout during paint). | |
139 // However to avoid deadlock, we must ensure that any message that's sent as | |
140 // a result of a sync call from the renderer must unblock the renderer. We | |
141 // additionally have to do this for async messages from the renderer that | |
142 // have the unblock flag set, since they could be followed by a sync message | |
143 // that won't get dispatched until the call to the renderer is complete. | |
144 bool send_unblocking_only_during_unblock_dispatch_; | |
145 | |
146 DISALLOW_COPY_AND_ASSIGN(NPChannelBase); | |
147 }; | |
148 | |
149 } // namespace content | |
150 | |
151 #endif // CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_ | |
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