1 //
2 //  Copyright 2015 Google, Inc.
3 //
4 //  Licensed under the Apache License, Version 2.0 (the "License");
5 //  you may not use this file except in compliance with the License.
6 //  You may obtain a copy of the License at:
7 //
8 //  http://www.apache.org/licenses/LICENSE-2.0
9 //
10 //  Unless required by applicable law or agreed to in writing, software
11 //  distributed under the License is distributed on an "AS IS" BASIS,
12 //  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 //  See the License for the specific language governing permissions and
14 //  limitations under the License.
15 //
16 
17 #pragma once
18 
19 #include <memory>
20 
21 #include <base/macros.h>
22 #include <base/memory/ref_counted.h>
23 
24 namespace bluetooth {
25 class Adapter;
26 }  // namespace bluetooth
27 
28 namespace ipc {
29 
30 class IPCHandler;
31 
32 // IPCManager is a class for initializing and running supported IPC mechanisms.
33 // It manages the life-time of different IPC flavors that are available on the
34 // system. There are two flavors: a Linux sequential packet domain socket based
35 // system and one based on the Binder-based android.bluetooth framework.
36 class IPCManager {
37  public:
38   // Possible IPC types.
39   enum Type {
40     TYPE_LINUX,   // IPC based on a Linux sequential packet domain socket
41     TYPE_BINDER,  // IPC based on the Binder
42     TYPE_DBUS     // IPC based on the DBus
43   };
44 
45   // Interface for observing events from an IPC mechanism. These methods will be
46   // called on the thread that started the particular IPC type.
47   class Delegate {
48    public:
49     Delegate() = default;
50     virtual ~Delegate() = default;
51 
52     // Called when an IPC mechanism has successfully started and is ready for
53     // client connections.
54     virtual void OnIPCHandlerStarted(Type type) = 0;
55 
56     // Called when an IPC mechanism has stopped. This may happen due to an error
57     // in initialization or due to a regular shut down routine.
58     virtual void OnIPCHandlerStopped(Type type) = 0;
59 
60    private:
61     DISALLOW_COPY_AND_ASSIGN(Delegate);
62   };
63 
64   explicit IPCManager(bluetooth::Adapter* adapter);
65   ~IPCManager();
66 
67   // Initialize the underlying IPC handler based on |type|, if that type has not
68   // yet been initialized and returns true on success. Returns false if that
69   // type has already been initialized or an error occurs.
70   //
71   // If TYPE_LINUX is given, the file path to use for the domain socket will be
72   // obtained from the global Settings object. Hence, the Settings object must
73   // have been initialized before calling this method.
74   //
75   // |delegate| must out-live the IPCManager and the underlying handler. Users
76   // can guarantee proper clean up by deallocating |delegate| when or after
77   // Delegate::OnIPCHandlerStopped is called. It is safe to destroy |delegate|
78   // after destroying the IPCManager instance, as the destructor will join and
79   // clean up all underlying threads.
80   bool Start(Type type, Delegate* delegate);
81 
82   // Returns true if an IPC type has been initialized.
83   bool BinderStarted() const;
84   bool LinuxStarted() const;
85   bool DBusStarted() const;
86 
87  private:
88   IPCManager() = default;
89 
90   // Pointers to the different IPC handler classes. These are initialized and
91   // owned by us.
92   scoped_refptr<IPCHandler> binder_handler_;
93   scoped_refptr<IPCHandler> linux_handler_;
94   scoped_refptr<IPCHandler> dbus_handler_;
95 
96   // The Bluetooth adapter instance. This is owned by Daemon so we keep a raw
97   // pointer to it.
98   bluetooth::Adapter* adapter_;
99 
100   DISALLOW_COPY_AND_ASSIGN(IPCManager);
101 };
102 
103 }  // namespace ipc
104