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 
17 #include "l2cap/internal/scheduler_fifo.h"
18 
19 #include "dynamic_channel_impl.h"
20 #include "l2cap/internal/data_pipeline_manager.h"
21 #include "l2cap/l2cap_packets.h"
22 #include "os/log.h"
23 
24 namespace bluetooth {
25 namespace l2cap {
26 namespace internal {
27 
Fifo(DataPipelineManager * data_pipeline_manager,LowerQueueUpEnd * link_queue_up_end,os::Handler * handler)28 Fifo::Fifo(DataPipelineManager* data_pipeline_manager, LowerQueueUpEnd* link_queue_up_end, os::Handler* handler)
29     : data_pipeline_manager_(data_pipeline_manager), link_queue_up_end_(link_queue_up_end), handler_(handler) {
30   log::assert_that(
31       link_queue_up_end_ != nullptr && handler_ != nullptr,
32       "assert failed: link_queue_up_end_ != nullptr && handler_ != nullptr");
33 }
34 
35 // Invoked from some external Handler context
~Fifo()36 Fifo::~Fifo() {
37   // TODO(hsz): notify Sender don't send callback to me
38   if (link_queue_enqueue_registered_.exchange(false)) {
39     link_queue_up_end_->UnregisterEnqueue();
40   }
41 }
42 
43 // Invoked within L2CAP Handler context
OnPacketsReady(Cid cid,int number_packets)44 void Fifo::OnPacketsReady(Cid cid, int number_packets) {
45   if (number_packets == 0) {
46     return;
47   }
48   int priority = high_priority_cids_.count(cid) != 0;
49   next_to_dequeue_and_num_packets.push(std::make_pair(cid, number_packets), priority);
50   try_register_link_queue_enqueue();
51 }
52 
53 // Invoked within L2CAP Handler context
SetChannelTxPriority(Cid cid,bool high_priority)54 void Fifo::SetChannelTxPriority(Cid cid, bool high_priority) {
55   if (high_priority) {
56     high_priority_cids_.emplace(cid);
57   } else {
58     high_priority_cids_.erase(cid);
59   }
60 }
61 
RemoveChannel(Cid cid)62 void Fifo::RemoveChannel(Cid cid) {
63   for (size_t i = 0; i < next_to_dequeue_and_num_packets.size(); i++) {
64     auto& channel_id_and_number_packets = next_to_dequeue_and_num_packets.front();
65     if (channel_id_and_number_packets.second != cid) {
66       next_to_dequeue_and_num_packets.push(channel_id_and_number_packets);
67     }
68     next_to_dequeue_and_num_packets.pop();
69   }
70   if (next_to_dequeue_and_num_packets.empty() && link_queue_enqueue_registered_.exchange(false)) {
71     link_queue_up_end_->UnregisterEnqueue();
72   }
73 }
74 
75 // Invoked from some external Queue Reactable context
link_queue_enqueue_callback()76 std::unique_ptr<Fifo::UpperDequeue> Fifo::link_queue_enqueue_callback() {
77   log::assert_that(
78       !next_to_dequeue_and_num_packets.empty(),
79       "assert failed: !next_to_dequeue_and_num_packets.empty()");
80   auto& channel_id_and_number_packets = next_to_dequeue_and_num_packets.front();
81   auto channel_id = channel_id_and_number_packets.first;
82   channel_id_and_number_packets.second--;
83   if (channel_id_and_number_packets.second == 0) {
84     next_to_dequeue_and_num_packets.pop();
85   }
86   auto packet = data_pipeline_manager_->GetDataController(channel_id)->GetNextPacket();
87 
88   data_pipeline_manager_->OnPacketSent(channel_id);
89   if (next_to_dequeue_and_num_packets.empty() && link_queue_enqueue_registered_.exchange(false)) {
90     link_queue_up_end_->UnregisterEnqueue();
91   }
92   return packet;
93 }
94 
try_register_link_queue_enqueue()95 void Fifo::try_register_link_queue_enqueue() {
96   if (link_queue_enqueue_registered_.exchange(true)) {
97     return;
98   }
99   link_queue_up_end_->RegisterEnqueue(handler_,
100                                       common::Bind(&Fifo::link_queue_enqueue_callback, common::Unretained(this)));
101 }
102 
103 }  // namespace internal
104 }  // namespace l2cap
105 }  // namespace bluetooth
106