1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/*
* Copyright (c) 2021 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <glog/logging.h>
#include <protocols/rtc/rtc_consts.h>
#include <protocols/rtc/rtc_rs_delay.h>
namespace transport {
namespace protocol {
namespace rtc {
RecoveryStrategyDelayBased::RecoveryStrategyDelayBased(
Indexer *indexer, SendRtxCallback &&callback, asio::io_service &io_service,
interface::RtcTransportRecoveryStrategies rs_type,
interface::StrategyCallback &&external_callback)
: RecoveryStrategy(indexer, std::move(callback), io_service, true, false,
rs_type,
std::move(external_callback)), // start with rtx
congestion_state_(false),
probing_state_(false),
switch_rounds_(0) {}
RecoveryStrategyDelayBased::RecoveryStrategyDelayBased(RecoveryStrategy &&rs)
: RecoveryStrategy(std::move(rs)) {
setRtxFec(true, false);
// we have to re-init congestion and
// probing
switch_rounds_ = 0;
congestion_state_ = false;
probing_state_ = false;
}
RecoveryStrategyDelayBased::~RecoveryStrategyDelayBased() {}
void RecoveryStrategyDelayBased::turnOnRecovery() {
recovery_on_ = true;
uint64_t rtt = state_->getMinRTT();
uint32_t fec_to_ask = computeFecPacketsToAsk();
if (rtt > MAX_RTT_BEFORE_FEC && fec_to_ask > 0) {
// we need to start FEC (see fec only strategy for more details)
setRtxFec(true, true);
rtx_during_fec_ = 1; // avoid to stop fec
indexer_->setNFec(fec_to_ask);
} else {
// use RTX
setRtxFec(true, false);
switch_rounds_ = 0;
}
}
void RecoveryStrategyDelayBased::softSwitchToFec(uint32_t fec_to_ask) {
if (fec_to_ask == 0) {
setRtxFec(true, false);
switch_rounds_ = 0;
} else {
switch_rounds_++;
if (switch_rounds_ >= ((RTC_INTEREST_LIFETIME / ROUND_LEN) * 2) &&
rtx_during_fec_ != 0) { // go to fec only if it is needed (RTX are on)
setRtxFec(false, true);
} else {
setRtxFec(true, true);
}
}
}
void RecoveryStrategyDelayBased::onNewRound(bool in_sync) {
if (!recovery_on_) {
// disable fec so that no extra packet will be sent
// for rtx we check if recovery is on in newPacketLoss
setRtxFec(true, false);
indexer_->setNFec(0);
return;
}
uint64_t rtt = state_->getAvgRTT();
// XXX at the moment we are not looking at congestion events
// bool congestion = rc_->inCongestionState();
if ((!fec_on_ && rtt >= MAX_RTT_BEFORE_FEC) ||
(fec_on_ && rtt > (MAX_RTT_BEFORE_FEC - 10))) {
// switch from rtx to fec or keep use fec. Notice that if some rtx are
// waiting to be scheduled, they will be sent normally, but no new rtx will
// be created if the loss rate is 0 keep to use RTX.
uint32_t fec_to_ask = computeFecPacketsToAsk();
softSwitchToFec(fec_to_ask);
if (rtx_during_fec_ == 0) // if we do not send any RTX the losses
// registered may be due to jitter
indexer_->setNFec(0);
else
indexer_->setNFec(fec_to_ask);
return;
}
if ((fec_on_ && rtt <= (MAX_RTT_BEFORE_FEC - 10)) ||
(!rtx_on_ && rtt <= MAX_RTT_BEFORE_FEC)) {
// turn on rtx
softSwitchToFec(0);
indexer_->setNFec(0);
return;
}
}
void RecoveryStrategyDelayBased::newPacketLoss(uint32_t seq) {
if (rtx_on_ && recovery_on_) {
addNewRtx(seq, false);
} else {
if (!state_->isPending(seq) && !indexer_->isFec(seq)) {
addNewRtx(seq, true);
} else {
recover_with_fec_.insert(seq);
state_->onPossibleLossWithNoRtx(seq);
}
}
}
void RecoveryStrategyDelayBased::receivedPacket(uint32_t seq) {
removePacketState(seq);
}
void RecoveryStrategyDelayBased::probing() {
// TODO
// for the moment ask for all fec and exit the probing phase
probing_state_ = false;
setRtxFec(false, true);
indexer_->setNFec(computeFecPacketsToAsk());
}
} // end namespace rtc
} // end namespace protocol
} // end namespace transport
|
