test/network/cross_traffic.cc - src - Git at Google

 /*
  *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "test/network/cross_traffic.h"

 #include <math.h>

 #include <optional>
 #include <utility>

 #include "absl/memory/memory.h"
 #include "cross_traffic.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/numerics/safe_minmax.h"

 namespace webrtc {
 namespace test {

 RandomWalkCrossTraffic::RandomWalkCrossTraffic(RandomWalkConfig config,
                                                CrossTrafficRoute* traffic_route)
     : config_(config),
       traffic_route_(traffic_route),
       random_(config_.random_seed) {
   sequence_checker_.Detach();
 }
 RandomWalkCrossTraffic::~RandomWalkCrossTraffic() = default;

 void RandomWalkCrossTraffic::Process(Timestamp at_time) {
   RTC_DCHECK_RUN_ON(&sequence_checker_);
   if (last_process_time_.IsMinusInfinity()) {
     last_process_time_ = at_time;
   }
   TimeDelta delta = at_time - last_process_time_;
   last_process_time_ = at_time;

   if (at_time - last_update_time_ >= config_.update_interval) {
     intensity_ += random_.Gaussian(config_.bias, config_.variance) *
                   sqrt((at_time - last_update_time_).seconds<double>());
     intensity_ = rtc::SafeClamp(intensity_, 0.0, 1.0);
     last_update_time_ = at_time;
   }
   pending_size_ += TrafficRate() * delta;

   if (pending_size_ >= config_.min_packet_size &&
       at_time >= last_send_time_ + config_.min_packet_interval) {
     traffic_route_->SendPacket(pending_size_.bytes());
     pending_size_ = DataSize::Zero();
     last_send_time_ = at_time;
   }
 }

 TimeDelta RandomWalkCrossTraffic::GetProcessInterval() const {
   return config_.min_packet_interval;
 }

 DataRate RandomWalkCrossTraffic::TrafficRate() const {
   RTC_DCHECK_RUN_ON(&sequence_checker_);
   return config_.peak_rate * intensity_;
 }

 ColumnPrinter RandomWalkCrossTraffic::StatsPrinter() {
   return ColumnPrinter::Lambda(
       "random_walk_cross_traffic_rate",
       [this](rtc::SimpleStringBuilder& sb) {
         sb.AppendFormat("%.0lf", TrafficRate().bps() / 8.0);
       },
       32);
 }

 PulsedPeaksCrossTraffic::PulsedPeaksCrossTraffic(
     PulsedPeaksConfig config,
     CrossTrafficRoute* traffic_route)
     : config_(config), traffic_route_(traffic_route) {
   sequence_checker_.Detach();
 }
 PulsedPeaksCrossTraffic::~PulsedPeaksCrossTraffic() = default;

 void PulsedPeaksCrossTraffic::Process(Timestamp at_time) {
   RTC_DCHECK_RUN_ON(&sequence_checker_);
   TimeDelta time_since_toggle = at_time - last_update_time_;
   if (time_since_toggle.IsInfinite() ||
       (sending_ && time_since_toggle >= config_.send_duration)) {
     sending_ = false;
     last_update_time_ = at_time;
   } else if (!sending_ && time_since_toggle >= config_.hold_duration) {
     sending_ = true;
     last_update_time_ = at_time;
     // Start sending period.
     last_send_time_ = at_time;
   }

   if (sending_) {
     DataSize pending_size = config_.peak_rate * (at_time - last_send_time_);

     if (pending_size >= config_.min_packet_size &&
         at_time >= last_send_time_ + config_.min_packet_interval) {
       traffic_route_->SendPacket(pending_size.bytes());
       last_send_time_ = at_time;
     }
   }
 }

 TimeDelta PulsedPeaksCrossTraffic::GetProcessInterval() const {
   return config_.min_packet_interval;
 }

 DataRate PulsedPeaksCrossTraffic::TrafficRate() const {
   RTC_DCHECK_RUN_ON(&sequence_checker_);
   return sending_ ? config_.peak_rate : DataRate::Zero();
 }

 ColumnPrinter PulsedPeaksCrossTraffic::StatsPrinter() {
   return ColumnPrinter::Lambda(
       "pulsed_peaks_cross_traffic_rate",
       [this](rtc::SimpleStringBuilder& sb) {
         sb.AppendFormat("%.0lf", TrafficRate().bps() / 8.0);
       },
       32);
 }

 TcpMessageRouteImpl::TcpMessageRouteImpl(Clock* clock,
                                          TaskQueueBase* task_queue,
                                          EmulatedRoute* send_route,
                                          EmulatedRoute* ret_route)
     : clock_(clock),
       task_queue_(task_queue),
       request_route_(send_route,
                      [this](TcpPacket packet, Timestamp) {
                        OnRequest(std::move(packet));
                      }),
       response_route_(ret_route,
                       [this](TcpPacket packet, Timestamp arrival_time) {
                         OnResponse(std::move(packet), arrival_time);
                       }) {}

 void TcpMessageRouteImpl::SendMessage(size_t size,
                                       std::function<void()> on_received) {
   task_queue_->PostTask([this, size, handler = std::move(on_received)] {
     // If we are currently sending a message we won't reset the connection,
     // we'll act as if the messages are sent in the same TCP stream. This is
     // intended to simulate recreation of a TCP session for each message
     // in the typical case while avoiding the complexity overhead of
     // maintaining multiple virtual TCP sessions in parallel.
     if (pending_.empty() && in_flight_.empty()) {
       cwnd_ = 10;
       ssthresh_ = INFINITY;
     }
     int64_t data_left = static_cast<int64_t>(size);
     int64_t kMaxPacketSize = 1200;
     int64_t kMinPacketSize = 4;
     Message message{std::move(handler)};
     while (data_left > 0) {
       int64_t packet_size = std::min(data_left, kMaxPacketSize);
       int fragment_id = next_fragment_id_++;
       pending_.push_back(MessageFragment{
           fragment_id,
           static_cast<size_t>(std::max(kMinPacketSize, packet_size))});
       message.pending_fragment_ids.insert(fragment_id);
       data_left -= packet_size;
     }
     messages_.emplace_back(message);
     SendPackets(clock_->CurrentTime());
   });
 }

 void TcpMessageRouteImpl::OnRequest(TcpPacket packet_info) {
   for (auto it = messages_.begin(); it != messages_.end(); ++it) {
     if (it->pending_fragment_ids.count(packet_info.fragment.fragment_id) != 0) {
       it->pending_fragment_ids.erase(packet_info.fragment.fragment_id);
       if (it->pending_fragment_ids.empty()) {
         it->handler();
         messages_.erase(it);
       }
       break;
     }
   }
   const size_t kAckPacketSize = 20;
   response_route_.SendPacket(kAckPacketSize, packet_info);
 }

 void TcpMessageRouteImpl::OnResponse(TcpPacket packet_info, Timestamp at_time) {
   auto it = in_flight_.find(packet_info.sequence_number);
   if (it != in_flight_.end()) {
     last_rtt_ = at_time - packet_info.send_time;
     in_flight_.erase(it);
   }
   auto lost_end = in_flight_.lower_bound(packet_info.sequence_number);
   for (auto lost_it = in_flight_.begin(); lost_it != lost_end;
        lost_it = in_flight_.erase(lost_it)) {
     pending_.push_front(lost_it->second.fragment);
   }

   if (packet_info.sequence_number - last_acked_seq_num_ > 1) {
     HandleLoss(at_time);
   } else if (cwnd_ <= ssthresh_) {
     cwnd_ += 1;
   } else {
     cwnd_ += 1.0f / cwnd_;
   }
   last_acked_seq_num_ =
       std::max(packet_info.sequence_number, last_acked_seq_num_);
   SendPackets(at_time);
 }

 void TcpMessageRouteImpl::HandleLoss(Timestamp at_time) {
   if (at_time - last_reduction_time_ < last_rtt_)
     return;
   last_reduction_time_ = at_time;
   ssthresh_ = std::max(static_cast<int>(in_flight_.size() / 2), 2);
   cwnd_ = ssthresh_;
 }

 void TcpMessageRouteImpl::SendPackets(Timestamp at_time) {
   const TimeDelta kPacketTimeout = TimeDelta::Seconds(1);
   int cwnd = std::ceil(cwnd_);
   int packets_to_send = std::max(cwnd - static_cast<int>(in_flight_.size()), 0);
   while (packets_to_send-- > 0 && !pending_.empty()) {
     auto seq_num = next_sequence_number_++;
     TcpPacket send;
     send.sequence_number = seq_num;
     send.send_time = at_time;
     send.fragment = pending_.front();
     pending_.pop_front();
     request_route_.SendPacket(send.fragment.size, send);
     in_flight_.insert({seq_num, send});
     task_queue_->PostDelayedTask(
         [this, seq_num] {
           HandlePacketTimeout(seq_num, clock_->CurrentTime());
         },
         kPacketTimeout);
   }
 }

 void TcpMessageRouteImpl::HandlePacketTimeout(int seq_num, Timestamp at_time) {
   auto lost = in_flight_.find(seq_num);
   if (lost != in_flight_.end()) {
     pending_.push_front(lost->second.fragment);
     in_flight_.erase(lost);
     HandleLoss(at_time);
     SendPackets(at_time);
   }
 }

 FakeTcpCrossTraffic::FakeTcpCrossTraffic(FakeTcpConfig config,
                                          EmulatedRoute* send_route,
                                          EmulatedRoute* ret_route)
     : conf_(config), route_(this, send_route, ret_route) {}

 TimeDelta FakeTcpCrossTraffic::GetProcessInterval() const {
   return conf_.process_interval;
 }

 void FakeTcpCrossTraffic::Process(Timestamp at_time) {
   SendPackets(at_time);
 }

 void FakeTcpCrossTraffic::OnRequest(int sequence_number, Timestamp at_time) {
   const size_t kAckPacketSize = 20;
   route_.SendResponse(kAckPacketSize, sequence_number);
 }

 void FakeTcpCrossTraffic::OnResponse(int sequence_number, Timestamp at_time) {
   ack_received_ = true;
   auto it = in_flight_.find(sequence_number);
   if (it != in_flight_.end()) {
     last_rtt_ = at_time - in_flight_.at(sequence_number);
     in_flight_.erase(sequence_number);
   }
   if (sequence_number - last_acked_seq_num_ > 1) {
     HandleLoss(at_time);
   } else if (cwnd_ <= ssthresh_) {
     cwnd_ += 1;
   } else {
     cwnd_ += 1.0f / cwnd_;
   }
   last_acked_seq_num_ = std::max(sequence_number, last_acked_seq_num_);
   SendPackets(at_time);
 }

 void FakeTcpCrossTraffic::HandleLoss(Timestamp at_time) {
   if (at_time - last_reduction_time_ < last_rtt_)
     return;
   last_reduction_time_ = at_time;
   ssthresh_ = std::max(static_cast<int>(in_flight_.size() / 2), 2);
   cwnd_ = ssthresh_;
 }

 void FakeTcpCrossTraffic::SendPackets(Timestamp at_time) {
   int cwnd = std::ceil(cwnd_);
   int packets_to_send = std::max(cwnd - static_cast<int>(in_flight_.size()), 0);
   bool timeouts = false;
   for (auto it = in_flight_.begin(); it != in_flight_.end();) {
     if (it->second < at_time - conf_.packet_timeout) {
       it = in_flight_.erase(it);
       timeouts = true;
     } else {
       ++it;
     }
   }
   if (timeouts)
     HandleLoss(at_time);
   for (int i = 0; i < packets_to_send; ++i) {
     if ((total_sent_ + conf_.packet_size) > conf_.send_limit) {
       break;
     }
     in_flight_.insert({next_sequence_number_, at_time});
     route_.SendRequest(conf_.packet_size.bytes<size_t>(),
                        next_sequence_number_++);
     total_sent_ += conf_.packet_size;
   }
 }

 }  // namespace test
 }  // namespace webrtc
	/*
	* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "test/network/cross_traffic.h"

	#include <math.h>

	#include <optional>
	#include <utility>

	#include "absl/memory/memory.h"
	#include "cross_traffic.h"
	#include "rtc_base/logging.h"
	#include "rtc_base/numerics/safe_minmax.h"

	namespace webrtc {
	namespace test {

	RandomWalkCrossTraffic::RandomWalkCrossTraffic(RandomWalkConfig config,
	CrossTrafficRoute* traffic_route)
	: config_(config),
	traffic_route_(traffic_route),
	random_(config_.random_seed) {
	sequence_checker_.Detach();
	}
	RandomWalkCrossTraffic::~RandomWalkCrossTraffic() = default;

	void RandomWalkCrossTraffic::Process(Timestamp at_time) {
	RTC_DCHECK_RUN_ON(&sequence_checker_);
	if (last_process_time_.IsMinusInfinity()) {
	last_process_time_ = at_time;
	}
	TimeDelta delta = at_time - last_process_time_;
	last_process_time_ = at_time;

	if (at_time - last_update_time_ >= config_.update_interval) {
	intensity_ += random_.Gaussian(config_.bias, config_.variance) *
	sqrt((at_time - last_update_time_).seconds<double>());
	intensity_ = rtc::SafeClamp(intensity_, 0.0, 1.0);
	last_update_time_ = at_time;
	}
	pending_size_ += TrafficRate() * delta;

	if (pending_size_ >= config_.min_packet_size &&
	at_time >= last_send_time_ + config_.min_packet_interval) {
	traffic_route_->SendPacket(pending_size_.bytes());
	pending_size_ = DataSize::Zero();
	last_send_time_ = at_time;
	}
	}

	TimeDelta RandomWalkCrossTraffic::GetProcessInterval() const {
	return config_.min_packet_interval;
	}

	DataRate RandomWalkCrossTraffic::TrafficRate() const {
	RTC_DCHECK_RUN_ON(&sequence_checker_);
	return config_.peak_rate * intensity_;
	}

	ColumnPrinter RandomWalkCrossTraffic::StatsPrinter() {
	return ColumnPrinter::Lambda(
	"random_walk_cross_traffic_rate",
	[this](rtc::SimpleStringBuilder& sb) {
	sb.AppendFormat("%.0lf", TrafficRate().bps() / 8.0);
	},
	32);
	}

	PulsedPeaksCrossTraffic::PulsedPeaksCrossTraffic(
	PulsedPeaksConfig config,
	CrossTrafficRoute* traffic_route)
	: config_(config), traffic_route_(traffic_route) {
	sequence_checker_.Detach();
	}
	PulsedPeaksCrossTraffic::~PulsedPeaksCrossTraffic() = default;

	void PulsedPeaksCrossTraffic::Process(Timestamp at_time) {
	RTC_DCHECK_RUN_ON(&sequence_checker_);
	TimeDelta time_since_toggle = at_time - last_update_time_;
	if (time_since_toggle.IsInfinite() \|\|
	(sending_ && time_since_toggle >= config_.send_duration)) {
	sending_ = false;
	last_update_time_ = at_time;
	} else if (!sending_ && time_since_toggle >= config_.hold_duration) {
	sending_ = true;
	last_update_time_ = at_time;
	// Start sending period.
	last_send_time_ = at_time;
	}

	if (sending_) {
	DataSize pending_size = config_.peak_rate * (at_time - last_send_time_);

	if (pending_size >= config_.min_packet_size &&
	at_time >= last_send_time_ + config_.min_packet_interval) {
	traffic_route_->SendPacket(pending_size.bytes());
	last_send_time_ = at_time;
	}
	}
	}

	TimeDelta PulsedPeaksCrossTraffic::GetProcessInterval() const {
	return config_.min_packet_interval;
	}

	DataRate PulsedPeaksCrossTraffic::TrafficRate() const {
	RTC_DCHECK_RUN_ON(&sequence_checker_);
	return sending_ ? config_.peak_rate : DataRate::Zero();
	}

	ColumnPrinter PulsedPeaksCrossTraffic::StatsPrinter() {
	return ColumnPrinter::Lambda(
	"pulsed_peaks_cross_traffic_rate",
	[this](rtc::SimpleStringBuilder& sb) {
	sb.AppendFormat("%.0lf", TrafficRate().bps() / 8.0);
	},
	32);
	}

	TcpMessageRouteImpl::TcpMessageRouteImpl(Clock* clock,
	TaskQueueBase* task_queue,
	EmulatedRoute* send_route,
	EmulatedRoute* ret_route)
	: clock_(clock),
	task_queue_(task_queue),
	request_route_(send_route,
	[this](TcpPacket packet, Timestamp) {
	OnRequest(std::move(packet));
	}),
	response_route_(ret_route,
	[this](TcpPacket packet, Timestamp arrival_time) {
	OnResponse(std::move(packet), arrival_time);
	}) {}

	void TcpMessageRouteImpl::SendMessage(size_t size,
	std::function<void()> on_received) {
	task_queue_->PostTask([this, size, handler = std::move(on_received)] {
	// If we are currently sending a message we won't reset the connection,
	// we'll act as if the messages are sent in the same TCP stream. This is
	// intended to simulate recreation of a TCP session for each message
	// in the typical case while avoiding the complexity overhead of
	// maintaining multiple virtual TCP sessions in parallel.
	if (pending_.empty() && in_flight_.empty()) {
	cwnd_ = 10;
	ssthresh_ = INFINITY;
	}
	int64_t data_left = static_cast<int64_t>(size);
	int64_t kMaxPacketSize = 1200;
	int64_t kMinPacketSize = 4;
	Message message{std::move(handler)};
	while (data_left > 0) {
	int64_t packet_size = std::min(data_left, kMaxPacketSize);
	int fragment_id = next_fragment_id_++;
	pending_.push_back(MessageFragment{
	fragment_id,
	static_cast<size_t>(std::max(kMinPacketSize, packet_size))});
	message.pending_fragment_ids.insert(fragment_id);
	data_left -= packet_size;
	}
	messages_.emplace_back(message);
	SendPackets(clock_->CurrentTime());
	});
	}

	void TcpMessageRouteImpl::OnRequest(TcpPacket packet_info) {
	for (auto it = messages_.begin(); it != messages_.end(); ++it) {
	if (it->pending_fragment_ids.count(packet_info.fragment.fragment_id) != 0) {
	it->pending_fragment_ids.erase(packet_info.fragment.fragment_id);
	if (it->pending_fragment_ids.empty()) {
	it->handler();
	messages_.erase(it);
	}
	break;
	}
	}
	const size_t kAckPacketSize = 20;
	response_route_.SendPacket(kAckPacketSize, packet_info);
	}

	void TcpMessageRouteImpl::OnResponse(TcpPacket packet_info, Timestamp at_time) {
	auto it = in_flight_.find(packet_info.sequence_number);
	if (it != in_flight_.end()) {
	last_rtt_ = at_time - packet_info.send_time;
	in_flight_.erase(it);
	}
	auto lost_end = in_flight_.lower_bound(packet_info.sequence_number);
	for (auto lost_it = in_flight_.begin(); lost_it != lost_end;
	lost_it = in_flight_.erase(lost_it)) {
	pending_.push_front(lost_it->second.fragment);
	}

	if (packet_info.sequence_number - last_acked_seq_num_ > 1) {
	HandleLoss(at_time);
	} else if (cwnd_ <= ssthresh_) {
	cwnd_ += 1;
	} else {
	cwnd_ += 1.0f / cwnd_;
	}
	last_acked_seq_num_ =
	std::max(packet_info.sequence_number, last_acked_seq_num_);
	SendPackets(at_time);
	}

	void TcpMessageRouteImpl::HandleLoss(Timestamp at_time) {
	if (at_time - last_reduction_time_ < last_rtt_)
	return;
	last_reduction_time_ = at_time;
	ssthresh_ = std::max(static_cast<int>(in_flight_.size() / 2), 2);
	cwnd_ = ssthresh_;
	}

	void TcpMessageRouteImpl::SendPackets(Timestamp at_time) {
	const TimeDelta kPacketTimeout = TimeDelta::Seconds(1);
	int cwnd = std::ceil(cwnd_);
	int packets_to_send = std::max(cwnd - static_cast<int>(in_flight_.size()), 0);
	while (packets_to_send-- > 0 && !pending_.empty()) {
	auto seq_num = next_sequence_number_++;
	TcpPacket send;
	send.sequence_number = seq_num;
	send.send_time = at_time;
	send.fragment = pending_.front();
	pending_.pop_front();
	request_route_.SendPacket(send.fragment.size, send);
	in_flight_.insert({seq_num, send});
	task_queue_->PostDelayedTask(
	[this, seq_num] {
	HandlePacketTimeout(seq_num, clock_->CurrentTime());
	},
	kPacketTimeout);
	}
	}

	void TcpMessageRouteImpl::HandlePacketTimeout(int seq_num, Timestamp at_time) {
	auto lost = in_flight_.find(seq_num);
	if (lost != in_flight_.end()) {
	pending_.push_front(lost->second.fragment);
	in_flight_.erase(lost);
	HandleLoss(at_time);
	SendPackets(at_time);
	}
	}

	FakeTcpCrossTraffic::FakeTcpCrossTraffic(FakeTcpConfig config,
	EmulatedRoute* send_route,
	EmulatedRoute* ret_route)
	: conf_(config), route_(this, send_route, ret_route) {}

	TimeDelta FakeTcpCrossTraffic::GetProcessInterval() const {
	return conf_.process_interval;
	}

	void FakeTcpCrossTraffic::Process(Timestamp at_time) {
	SendPackets(at_time);
	}

	void FakeTcpCrossTraffic::OnRequest(int sequence_number, Timestamp at_time) {
	const size_t kAckPacketSize = 20;
	route_.SendResponse(kAckPacketSize, sequence_number);
	}

	void FakeTcpCrossTraffic::OnResponse(int sequence_number, Timestamp at_time) {
	ack_received_ = true;
	auto it = in_flight_.find(sequence_number);
	if (it != in_flight_.end()) {
	last_rtt_ = at_time - in_flight_.at(sequence_number);
	in_flight_.erase(sequence_number);
	}
	if (sequence_number - last_acked_seq_num_ > 1) {
	HandleLoss(at_time);
	} else if (cwnd_ <= ssthresh_) {
	cwnd_ += 1;
	} else {
	cwnd_ += 1.0f / cwnd_;
	}
	last_acked_seq_num_ = std::max(sequence_number, last_acked_seq_num_);
	SendPackets(at_time);
	}

	void FakeTcpCrossTraffic::HandleLoss(Timestamp at_time) {
	if (at_time - last_reduction_time_ < last_rtt_)
	return;
	last_reduction_time_ = at_time;
	ssthresh_ = std::max(static_cast<int>(in_flight_.size() / 2), 2);
	cwnd_ = ssthresh_;
	}

	void FakeTcpCrossTraffic::SendPackets(Timestamp at_time) {
	int cwnd = std::ceil(cwnd_);
	int packets_to_send = std::max(cwnd - static_cast<int>(in_flight_.size()), 0);
	bool timeouts = false;
	for (auto it = in_flight_.begin(); it != in_flight_.end();) {
	if (it->second < at_time - conf_.packet_timeout) {
	it = in_flight_.erase(it);
	timeouts = true;
	} else {
	++it;
	}
	}
	if (timeouts)
	HandleLoss(at_time);
	for (int i = 0; i < packets_to_send; ++i) {
	if ((total_sent_ + conf_.packet_size) > conf_.send_limit) {
	break;
	}
	in_flight_.insert({next_sequence_number_, at_time});
	route_.SendRequest(conf_.packet_size.bytes<size_t>(),
	next_sequence_number_++);
	total_sent_ += conf_.packet_size;
	}
	}

	} // namespace test
	} // namespace webrtc