1 // Copyright (c) 2012 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_PUBLIC_BROWSER_BROWSER_MESSAGE_FILTER_H_ 6 #define CONTENT_PUBLIC_BROWSER_BROWSER_MESSAGE_FILTER_H_ 7 8 #include "base/process/process.h" 9 #include "content/common/content_export.h" 10 #include "content/public/browser/browser_thread.h" 11 #include "ipc/ipc_channel_proxy.h" 12 13 #if defined(OS_WIN) 14 #include "base/synchronization/lock.h" 15 #endif 16 17 namespace base { 18 class TaskRunner; 19 } 20 21 namespace content { 22 23 // Base class for message filters in the browser process. You can receive and 24 // send messages on any thread. 25 class CONTENT_EXPORT BrowserMessageFilter 26 : public IPC::ChannelProxy::MessageFilter, 27 public IPC::Sender { 28 public: 29 BrowserMessageFilter(); 30 31 // IPC::ChannelProxy::MessageFilter methods. If you override them, make sure 32 // to call them as well. These are always called on the IO thread. 33 virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE; 34 virtual void OnChannelClosing() OVERRIDE; 35 virtual void OnChannelConnected(int32 peer_pid) OVERRIDE; 36 // DON'T OVERRIDE THIS! Override the other version below. 37 virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE; 38 39 // IPC::Sender implementation. Can be called on any thread. Can't send sync 40 // messages (since we don't want to block the browser on any other process). 41 virtual bool Send(IPC::Message* message) OVERRIDE; 42 43 // If you want the given message to be dispatched to your OnMessageReceived on 44 // a different thread, there are two options, either 45 // OverrideThreadForMessage or OverrideTaskRunnerForMessage. 46 // If neither is overriden, the message will be dispatched on the IO thread. 47 48 // If you want the message to be dispatched on a particular well-known 49 // browser thread, change |thread| to the id of the target thread 50 virtual void OverrideThreadForMessage( 51 const IPC::Message& message, 52 BrowserThread::ID* thread); 53 54 // If you want the message to be dispatched via the SequencedWorkerPool, 55 // return a non-null task runner which will target tasks accordingly. 56 // Note: To target the UI thread, please use OverrideThreadForMessage 57 // since that has extra checks to avoid deadlocks. 58 virtual base::TaskRunner* OverrideTaskRunnerForMessage( 59 const IPC::Message& message); 60 61 // Override this to receive messages. 62 // Your function will normally be called on the IO thread. However, if your 63 // OverrideXForMessage modifies the thread used to dispatch the message, 64 // your function will be called on the requested thread. 65 virtual bool OnMessageReceived(const IPC::Message& message, 66 bool* message_was_ok) = 0; 67 68 // Can be called on any thread, after OnChannelConnected is called. 69 base::ProcessHandle PeerHandle(); 70 71 // Can be called on any thread, after OnChannelConnected is called. 72 base::ProcessId peer_pid() const { return peer_pid_; } 73 74 // Checks that the given message can be dispatched on the UI thread, depending 75 // on the platform. If not, returns false and an error ot the sender. 76 static bool CheckCanDispatchOnUI(const IPC::Message& message, 77 IPC::Sender* sender); 78 79 // Call this if a message couldn't be deserialized. This kills the renderer. 80 // Can be called on any thread. 81 virtual void BadMessageReceived(); 82 83 protected: 84 virtual ~BrowserMessageFilter(); 85 86 private: 87 // Dispatches a message to the derived class. 88 bool DispatchMessage(const IPC::Message& message); 89 90 IPC::Channel* channel_; 91 base::ProcessId peer_pid_; 92 93 #if defined(OS_WIN) 94 base::Lock peer_handle_lock_; 95 base::ProcessHandle peer_handle_; 96 #endif 97 }; 98 99 } // namespace content 100 101 #endif // CONTENT_PUBLIC_BROWSER_BROWSER_MESSAGE_FILTER_H_ 102
