1 /*
2  * Copyright 2019 The Android Open Source Project
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 #pragma once
17 
18 #include "common/bidi_queue.h"
19 #include "common/callback.h"
20 #include "hci/acl_manager.h"
21 #include "os/handler.h"
22 #include "packet/base_packet_builder.h"
23 #include "packet/packet_view.h"
24 
25 namespace bluetooth {
26 namespace l2cap {
27 
28 namespace internal {
29 class DynamicChannelImpl;
30 }  // namespace internal
31 
32 /**
33  * L2CAP Dynamic channel object. User needs to call Close() when user no longer wants to use it. Otherwise the link
34  * won't be disconnected.
35  */
36 class DynamicChannel {
37  public:
38   // Should only be constructed by modules that have access to LinkManager
39   DynamicChannel(std::shared_ptr<l2cap::internal::DynamicChannelImpl> impl, os::Handler* l2cap_handler)
40       : impl_(std::move(impl)), l2cap_handler_(l2cap_handler) {
41     ASSERT(impl_ != nullptr);
42     ASSERT(l2cap_handler_ != nullptr);
43   }
44 
45   hci::Address GetDevice() const;
46 
47   /**
48    * Register close callback. If close callback is registered, when a channel is closed, the channel's resource will
49    * only be freed after on_close callback is invoked. Otherwise, if no on_close callback is registered, the channel's
50    * resource will be freed immediately after closing.
51    *
52    * @param user_handler The handler used to invoke the callback on
53    * @param on_close_callback The callback invoked upon channel closing.
54    */
55   using OnCloseCallback = common::OnceCallback<void(hci::ErrorCode)>;
56   void RegisterOnCloseCallback(os::Handler* user_handler, OnCloseCallback on_close_callback);
57 
58   /**
59    * Indicate that this Dynamic Channel should be closed. OnCloseCallback will be invoked when channel close is done.
60    * L2cay layer may terminate this ACL connection to free the resource after channel is closed.
61    */
62   void Close();
63 
64   /**
65    * This method will retrieve the data channel queue to send and receive packets.
66    *
67    * {@see BidiQueueEnd}
68    *
69    * @return The upper end of a bi-directional queue.
70    */
71   common::BidiQueueEnd<packet::BasePacketBuilder, packet::PacketView<packet::kLittleEndian>>* GetQueueUpEnd() const;
72 
73  private:
74   std::shared_ptr<l2cap::internal::DynamicChannelImpl> impl_;
75   os::Handler* l2cap_handler_;
76 };
77 
78 }  // namespace l2cap
79 }  // namespace bluetooth
80