1 /*
2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "webrtc/modules/pacing/packet_router.h"
12
13 #include "webrtc/base/atomicops.h"
14 #include "webrtc/base/checks.h"
15 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
16 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
17 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
18
19 namespace webrtc {
20
PacketRouter()21 PacketRouter::PacketRouter() : transport_seq_(0) {
22 pacer_thread_checker_.DetachFromThread();
23 }
24
~PacketRouter()25 PacketRouter::~PacketRouter() {
26 RTC_DCHECK(rtp_modules_.empty());
27 }
28
AddRtpModule(RtpRtcp * rtp_module)29 void PacketRouter::AddRtpModule(RtpRtcp* rtp_module) {
30 rtc::CritScope cs(&modules_crit_);
31 RTC_DCHECK(std::find(rtp_modules_.begin(), rtp_modules_.end(), rtp_module) ==
32 rtp_modules_.end());
33 rtp_modules_.push_back(rtp_module);
34 }
35
RemoveRtpModule(RtpRtcp * rtp_module)36 void PacketRouter::RemoveRtpModule(RtpRtcp* rtp_module) {
37 rtc::CritScope cs(&modules_crit_);
38 RTC_DCHECK(std::find(rtp_modules_.begin(), rtp_modules_.end(), rtp_module) !=
39 rtp_modules_.end());
40 rtp_modules_.remove(rtp_module);
41 }
42
TimeToSendPacket(uint32_t ssrc,uint16_t sequence_number,int64_t capture_timestamp,bool retransmission,int probe_cluster_id)43 bool PacketRouter::TimeToSendPacket(uint32_t ssrc,
44 uint16_t sequence_number,
45 int64_t capture_timestamp,
46 bool retransmission,
47 int probe_cluster_id) {
48 RTC_DCHECK(pacer_thread_checker_.CalledOnValidThread());
49 rtc::CritScope cs(&modules_crit_);
50 for (auto* rtp_module : rtp_modules_) {
51 if (!rtp_module->SendingMedia())
52 continue;
53 if (ssrc == rtp_module->SSRC() || ssrc == rtp_module->FlexfecSsrc()) {
54 return rtp_module->TimeToSendPacket(ssrc, sequence_number,
55 capture_timestamp, retransmission,
56 probe_cluster_id);
57 }
58 }
59 return true;
60 }
61
TimeToSendPadding(size_t bytes_to_send,int probe_cluster_id)62 size_t PacketRouter::TimeToSendPadding(size_t bytes_to_send,
63 int probe_cluster_id) {
64 RTC_DCHECK(pacer_thread_checker_.CalledOnValidThread());
65 size_t total_bytes_sent = 0;
66 rtc::CritScope cs(&modules_crit_);
67 for (RtpRtcp* module : rtp_modules_) {
68 if (module->SendingMedia()) {
69 size_t bytes_sent = module->TimeToSendPadding(
70 bytes_to_send - total_bytes_sent, probe_cluster_id);
71 total_bytes_sent += bytes_sent;
72 if (total_bytes_sent >= bytes_to_send)
73 break;
74 }
75 }
76 return total_bytes_sent;
77 }
78
SetTransportWideSequenceNumber(uint16_t sequence_number)79 void PacketRouter::SetTransportWideSequenceNumber(uint16_t sequence_number) {
80 rtc::AtomicOps::ReleaseStore(&transport_seq_, sequence_number);
81 }
82
AllocateSequenceNumber()83 uint16_t PacketRouter::AllocateSequenceNumber() {
84 int prev_seq = rtc::AtomicOps::AcquireLoad(&transport_seq_);
85 int desired_prev_seq;
86 int new_seq;
87 do {
88 desired_prev_seq = prev_seq;
89 new_seq = (desired_prev_seq + 1) & 0xFFFF;
90 // Note: CompareAndSwap returns the actual value of transport_seq at the
91 // time the CAS operation was executed. Thus, if prev_seq is returned, the
92 // operation was successful - otherwise we need to retry. Saving the
93 // return value saves us a load on retry.
94 prev_seq = rtc::AtomicOps::CompareAndSwap(&transport_seq_, desired_prev_seq,
95 new_seq);
96 } while (prev_seq != desired_prev_seq);
97
98 return new_seq;
99 }
100
SendFeedback(rtcp::TransportFeedback * packet)101 bool PacketRouter::SendFeedback(rtcp::TransportFeedback* packet) {
102 rtc::CritScope cs(&modules_crit_);
103 for (auto* rtp_module : rtp_modules_) {
104 packet->SetSenderSsrc(rtp_module->SSRC());
105 if (rtp_module->SendFeedbackPacket(*packet))
106 return true;
107 }
108 return false;
109 }
110
111 } // namespace webrtc
112