call/fake_network_pipe.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 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 "call/fake_network_pipe.h"

 #include <string.h>

 #include <algorithm>
 #include <queue>
 #include <utility>
 #include <vector>

 #include "api/media_types.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "system_wrappers/include/clock.h"

 namespace webrtc {

 namespace {
 constexpr int64_t kLogIntervalMs = 5000;
 }  // namespace

 NetworkPacket::NetworkPacket(rtc::CopyOnWriteBuffer packet,
                              int64_t send_time,
                              int64_t arrival_time,
                              absl::optional<PacketOptions> packet_options,
                              bool is_rtcp,
                              MediaType media_type,
                              absl::optional<int64_t> packet_time_us,
                              Transport* transport)
     : packet_(std::move(packet)),
       send_time_(send_time),
       arrival_time_(arrival_time),
       packet_options_(packet_options),
       is_rtcp_(is_rtcp),
       media_type_(media_type),
       packet_time_us_(packet_time_us),
       transport_(transport) {}

 NetworkPacket::NetworkPacket(NetworkPacket&& o)
     : packet_(std::move(o.packet_)),
       send_time_(o.send_time_),
       arrival_time_(o.arrival_time_),
       packet_options_(o.packet_options_),
       is_rtcp_(o.is_rtcp_),
       media_type_(o.media_type_),
       packet_time_us_(o.packet_time_us_),
       transport_(o.transport_) {}

 NetworkPacket::~NetworkPacket() = default;

 NetworkPacket& NetworkPacket::operator=(NetworkPacket&& o) {
   packet_ = std::move(o.packet_);
   send_time_ = o.send_time_;
   arrival_time_ = o.arrival_time_;
   packet_options_ = o.packet_options_;
   is_rtcp_ = o.is_rtcp_;
   media_type_ = o.media_type_;
   packet_time_us_ = o.packet_time_us_;
   transport_ = o.transport_;

   return *this;
 }

 FakeNetworkPipe::FakeNetworkPipe(
     Clock* clock,
     std::unique_ptr<NetworkBehaviorInterface> network_behavior)
     : FakeNetworkPipe(clock, std::move(network_behavior), nullptr, 1) {}

 FakeNetworkPipe::FakeNetworkPipe(
     Clock* clock,
     std::unique_ptr<NetworkBehaviorInterface> network_behavior,
     PacketReceiver* receiver)
     : FakeNetworkPipe(clock, std::move(network_behavior), receiver, 1) {}

 FakeNetworkPipe::FakeNetworkPipe(
     Clock* clock,
     std::unique_ptr<NetworkBehaviorInterface> network_behavior,
     PacketReceiver* receiver,
     uint64_t seed)
     : clock_(clock),
       network_behavior_(std::move(network_behavior)),
       receiver_(receiver),
       global_transport_(nullptr),
       clock_offset_ms_(0),
       dropped_packets_(0),
       sent_packets_(0),
       total_packet_delay_us_(0),
       last_log_time_us_(clock_->TimeInMicroseconds()) {}

 FakeNetworkPipe::FakeNetworkPipe(
     Clock* clock,
     std::unique_ptr<NetworkBehaviorInterface> network_behavior,
     Transport* transport)
     : clock_(clock),
       network_behavior_(std::move(network_behavior)),
       receiver_(nullptr),
       global_transport_(transport),
       clock_offset_ms_(0),
       dropped_packets_(0),
       sent_packets_(0),
       total_packet_delay_us_(0),
       last_log_time_us_(clock_->TimeInMicroseconds()) {
   RTC_DCHECK(global_transport_);
   AddActiveTransport(global_transport_);
 }

 FakeNetworkPipe::~FakeNetworkPipe() {
   if (global_transport_) {
     RemoveActiveTransport(global_transport_);
   }
   RTC_DCHECK(active_transports_.empty());
 }

 void FakeNetworkPipe::SetReceiver(PacketReceiver* receiver) {
   MutexLock lock(&config_lock_);
   receiver_ = receiver;
 }

 void FakeNetworkPipe::AddActiveTransport(Transport* transport) {
   MutexLock lock(&config_lock_);
   active_transports_[transport]++;
 }

 void FakeNetworkPipe::RemoveActiveTransport(Transport* transport) {
   MutexLock lock(&config_lock_);
   auto it = active_transports_.find(transport);
   RTC_CHECK(it != active_transports_.end());
   if (--(it->second) == 0) {
     active_transports_.erase(it);
   }
 }

 bool FakeNetworkPipe::SendRtp(const uint8_t* packet,
                               size_t length,
                               const PacketOptions& options) {
   RTC_DCHECK(global_transport_);
   EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), options, false,
                 global_transport_);
   return true;
 }

 bool FakeNetworkPipe::SendRtcp(const uint8_t* packet, size_t length) {
   RTC_DCHECK(global_transport_);
   EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), absl::nullopt, true,
                 global_transport_);
   return true;
 }

 bool FakeNetworkPipe::SendRtp(const uint8_t* packet,
                               size_t length,
                               const PacketOptions& options,
                               Transport* transport) {
   RTC_DCHECK(transport);
   EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), options, false,
                 transport);
   return true;
 }

 bool FakeNetworkPipe::SendRtcp(const uint8_t* packet,
                                size_t length,
                                Transport* transport) {
   RTC_DCHECK(transport);
   EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), absl::nullopt, true,
                 transport);
   return true;
 }

 PacketReceiver::DeliveryStatus FakeNetworkPipe::DeliverPacket(
     MediaType media_type,
     rtc::CopyOnWriteBuffer packet,
     int64_t packet_time_us) {
   return EnqueuePacket(std::move(packet), absl::nullopt, false, media_type,
                        packet_time_us)
              ? PacketReceiver::DELIVERY_OK
              : PacketReceiver::DELIVERY_PACKET_ERROR;
 }

 void FakeNetworkPipe::SetClockOffset(int64_t offset_ms) {
   MutexLock lock(&config_lock_);
   clock_offset_ms_ = offset_ms;
 }

 FakeNetworkPipe::StoredPacket::StoredPacket(NetworkPacket&& packet)
     : packet(std::move(packet)) {}

 bool FakeNetworkPipe::EnqueuePacket(rtc::CopyOnWriteBuffer packet,
                                     absl::optional<PacketOptions> options,
                                     bool is_rtcp,
                                     MediaType media_type,
                                     absl::optional<int64_t> packet_time_us) {
   MutexLock lock(&process_lock_);
   int64_t time_now_us = clock_->TimeInMicroseconds();
   return EnqueuePacket(NetworkPacket(std::move(packet), time_now_us,
                                      time_now_us, options, is_rtcp, media_type,
                                      packet_time_us, nullptr));
 }

 bool FakeNetworkPipe::EnqueuePacket(rtc::CopyOnWriteBuffer packet,
                                     absl::optional<PacketOptions> options,
                                     bool is_rtcp,
                                     Transport* transport) {
   MutexLock lock(&process_lock_);
   int64_t time_now_us = clock_->TimeInMicroseconds();
   return EnqueuePacket(NetworkPacket(std::move(packet), time_now_us,
                                      time_now_us, options, is_rtcp,
                                      MediaType::ANY, absl::nullopt, transport));
 }

 bool FakeNetworkPipe::EnqueuePacket(NetworkPacket&& net_packet) {
   int64_t send_time_us = net_packet.send_time();
   size_t packet_size = net_packet.data_length();

   packets_in_flight_.emplace_back(StoredPacket(std::move(net_packet)));
   int64_t packet_id = reinterpret_cast<uint64_t>(&packets_in_flight_.back());
   bool sent = network_behavior_->EnqueuePacket(
       PacketInFlightInfo(packet_size, send_time_us, packet_id));

   if (!sent) {
     packets_in_flight_.pop_back();
     ++dropped_packets_;
   }
   return sent;
 }

 float FakeNetworkPipe::PercentageLoss() {
   MutexLock lock(&process_lock_);
   if (sent_packets_ == 0)
     return 0;

   return static_cast<float>(dropped_packets_) /
          (sent_packets_ + dropped_packets_);
 }

 int FakeNetworkPipe::AverageDelay() {
   MutexLock lock(&process_lock_);
   if (sent_packets_ == 0)
     return 0;

   return static_cast<int>(total_packet_delay_us_ /
                           (1000 * static_cast<int64_t>(sent_packets_)));
 }

 size_t FakeNetworkPipe::DroppedPackets() {
   MutexLock lock(&process_lock_);
   return dropped_packets_;
 }

 size_t FakeNetworkPipe::SentPackets() {
   MutexLock lock(&process_lock_);
   return sent_packets_;
 }

 void FakeNetworkPipe::Process() {
   int64_t time_now_us;
   std::queue<NetworkPacket> packets_to_deliver;
   {
     MutexLock lock(&process_lock_);
     time_now_us = clock_->TimeInMicroseconds();
     if (time_now_us - last_log_time_us_ > kLogIntervalMs * 1000) {
       int64_t queueing_delay_us = 0;
       if (!packets_in_flight_.empty())
         queueing_delay_us =
             time_now_us - packets_in_flight_.front().packet.send_time();

       RTC_LOG(LS_INFO) << "Network queue: " << queueing_delay_us / 1000
                        << " ms.";
       last_log_time_us_ = time_now_us;
     }

     std::vector<PacketDeliveryInfo> delivery_infos =
         network_behavior_->DequeueDeliverablePackets(time_now_us);
     for (auto& delivery_info : delivery_infos) {
       // In the common case where no reordering happens, find will return early
       // as the first packet will be a match.
       auto packet_it =
           std::find_if(packets_in_flight_.begin(), packets_in_flight_.end(),
                        [&delivery_info](StoredPacket& packet_ref) {
                          return reinterpret_cast<uint64_t>(&packet_ref) ==
                                 delivery_info.packet_id;
                        });
       // Check that the packet is in the deque of packets in flight.
       RTC_CHECK(packet_it != packets_in_flight_.end());
       // Check that the packet is not already removed.
       RTC_DCHECK(!packet_it->removed);

       NetworkPacket packet = std::move(packet_it->packet);
       packet_it->removed = true;

       // Cleanup of removed packets at the beginning of the deque.
       while (!packets_in_flight_.empty() &&
              packets_in_flight_.front().removed) {
         packets_in_flight_.pop_front();
       }

       if (delivery_info.receive_time_us != PacketDeliveryInfo::kNotReceived) {
         int64_t added_delay_us =
             delivery_info.receive_time_us - packet.send_time();
         packet.IncrementArrivalTime(added_delay_us);
         packets_to_deliver.emplace(std::move(packet));
         // `time_now_us` might be later than when the packet should have
         // arrived, due to NetworkProcess being called too late. For stats, use
         // the time it should have been on the link.
         total_packet_delay_us_ += added_delay_us;
         ++sent_packets_;
       } else {
         ++dropped_packets_;
       }
     }
   }

   MutexLock lock(&config_lock_);
   while (!packets_to_deliver.empty()) {
     NetworkPacket packet = std::move(packets_to_deliver.front());
     packets_to_deliver.pop();
     DeliverNetworkPacket(&packet);
   }
 }

 void FakeNetworkPipe::DeliverNetworkPacket(NetworkPacket* packet) {
   Transport* transport = packet->transport();
   if (transport) {
     RTC_DCHECK(!receiver_);
     if (active_transports_.find(transport) == active_transports_.end()) {
       // Transport has been destroyed, ignore this packet.
       return;
     }
     if (packet->is_rtcp()) {
       transport->SendRtcp(packet->data(), packet->data_length());
     } else {
       transport->SendRtp(packet->data(), packet->data_length(),
                          packet->packet_options());
     }
   } else if (receiver_) {
     int64_t packet_time_us = packet->packet_time_us().value_or(-1);
     if (packet_time_us != -1) {
       int64_t queue_time_us = packet->arrival_time() - packet->send_time();
       RTC_CHECK(queue_time_us >= 0);
       packet_time_us += queue_time_us;
       packet_time_us += (clock_offset_ms_ * 1000);
     }
     receiver_->DeliverPacket(packet->media_type(),
                              std::move(*packet->raw_packet()), packet_time_us);
   }
 }

 absl::optional<int64_t> FakeNetworkPipe::TimeUntilNextProcess() {
   MutexLock lock(&process_lock_);
   absl::optional<int64_t> delivery_us = network_behavior_->NextDeliveryTimeUs();
   if (delivery_us) {
     int64_t delay_us = *delivery_us - clock_->TimeInMicroseconds();
     return std::max<int64_t>((delay_us + 500) / 1000, 0);
   }
   return absl::nullopt;
 }

 bool FakeNetworkPipe::HasReceiver() const {
   MutexLock lock(&config_lock_);
   return receiver_ != nullptr;
 }

 void FakeNetworkPipe::DeliverPacketWithLock(NetworkPacket* packet) {
   MutexLock lock(&config_lock_);
   DeliverNetworkPacket(packet);
 }

 void FakeNetworkPipe::ResetStats() {
   MutexLock lock(&process_lock_);
   dropped_packets_ = 0;
   sent_packets_ = 0;
   total_packet_delay_us_ = 0;
 }

 int64_t FakeNetworkPipe::GetTimeInMicroseconds() const {
   return clock_->TimeInMicroseconds();
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 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 "call/fake_network_pipe.h"

	#include <string.h>

	#include <algorithm>
	#include <queue>
	#include <utility>
	#include <vector>

	#include "api/media_types.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/logging.h"
	#include "system_wrappers/include/clock.h"

	namespace webrtc {

	namespace {
	constexpr int64_t kLogIntervalMs = 5000;
	} // namespace

	NetworkPacket::NetworkPacket(rtc::CopyOnWriteBuffer packet,
	int64_t send_time,
	int64_t arrival_time,
	absl::optional<PacketOptions> packet_options,
	bool is_rtcp,
	MediaType media_type,
	absl::optional<int64_t> packet_time_us,
	Transport* transport)
	: packet_(std::move(packet)),
	send_time_(send_time),
	arrival_time_(arrival_time),
	packet_options_(packet_options),
	is_rtcp_(is_rtcp),
	media_type_(media_type),
	packet_time_us_(packet_time_us),
	transport_(transport) {}

	NetworkPacket::NetworkPacket(NetworkPacket&& o)
	: packet_(std::move(o.packet_)),
	send_time_(o.send_time_),
	arrival_time_(o.arrival_time_),
	packet_options_(o.packet_options_),
	is_rtcp_(o.is_rtcp_),
	media_type_(o.media_type_),
	packet_time_us_(o.packet_time_us_),
	transport_(o.transport_) {}

	NetworkPacket::~NetworkPacket() = default;

	NetworkPacket& NetworkPacket::operator=(NetworkPacket&& o) {
	packet_ = std::move(o.packet_);
	send_time_ = o.send_time_;
	arrival_time_ = o.arrival_time_;
	packet_options_ = o.packet_options_;
	is_rtcp_ = o.is_rtcp_;
	media_type_ = o.media_type_;
	packet_time_us_ = o.packet_time_us_;
	transport_ = o.transport_;

	return *this;
	}

	FakeNetworkPipe::FakeNetworkPipe(
	Clock* clock,
	std::unique_ptr<NetworkBehaviorInterface> network_behavior)
	: FakeNetworkPipe(clock, std::move(network_behavior), nullptr, 1) {}

	FakeNetworkPipe::FakeNetworkPipe(
	Clock* clock,
	std::unique_ptr<NetworkBehaviorInterface> network_behavior,
	PacketReceiver* receiver)
	: FakeNetworkPipe(clock, std::move(network_behavior), receiver, 1) {}

	FakeNetworkPipe::FakeNetworkPipe(
	Clock* clock,
	std::unique_ptr<NetworkBehaviorInterface> network_behavior,
	PacketReceiver* receiver,
	uint64_t seed)
	: clock_(clock),
	network_behavior_(std::move(network_behavior)),
	receiver_(receiver),
	global_transport_(nullptr),
	clock_offset_ms_(0),
	dropped_packets_(0),
	sent_packets_(0),
	total_packet_delay_us_(0),
	last_log_time_us_(clock_->TimeInMicroseconds()) {}

	FakeNetworkPipe::FakeNetworkPipe(
	Clock* clock,
	std::unique_ptr<NetworkBehaviorInterface> network_behavior,
	Transport* transport)
	: clock_(clock),
	network_behavior_(std::move(network_behavior)),
	receiver_(nullptr),
	global_transport_(transport),
	clock_offset_ms_(0),
	dropped_packets_(0),
	sent_packets_(0),
	total_packet_delay_us_(0),
	last_log_time_us_(clock_->TimeInMicroseconds()) {
	RTC_DCHECK(global_transport_);
	AddActiveTransport(global_transport_);
	}

	FakeNetworkPipe::~FakeNetworkPipe() {
	if (global_transport_) {
	RemoveActiveTransport(global_transport_);
	}
	RTC_DCHECK(active_transports_.empty());
	}

	void FakeNetworkPipe::SetReceiver(PacketReceiver* receiver) {
	MutexLock lock(&config_lock_);
	receiver_ = receiver;
	}

	void FakeNetworkPipe::AddActiveTransport(Transport* transport) {
	MutexLock lock(&config_lock_);
	active_transports_[transport]++;
	}

	void FakeNetworkPipe::RemoveActiveTransport(Transport* transport) {
	MutexLock lock(&config_lock_);
	auto it = active_transports_.find(transport);
	RTC_CHECK(it != active_transports_.end());
	if (--(it->second) == 0) {
	active_transports_.erase(it);
	}
	}

	bool FakeNetworkPipe::SendRtp(const uint8_t* packet,
	size_t length,
	const PacketOptions& options) {
	RTC_DCHECK(global_transport_);
	EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), options, false,
	global_transport_);
	return true;
	}

	bool FakeNetworkPipe::SendRtcp(const uint8_t* packet, size_t length) {
	RTC_DCHECK(global_transport_);
	EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), absl::nullopt, true,
	global_transport_);
	return true;
	}

	bool FakeNetworkPipe::SendRtp(const uint8_t* packet,
	size_t length,
	const PacketOptions& options,
	Transport* transport) {
	RTC_DCHECK(transport);
	EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), options, false,
	transport);
	return true;
	}

	bool FakeNetworkPipe::SendRtcp(const uint8_t* packet,
	size_t length,
	Transport* transport) {
	RTC_DCHECK(transport);
	EnqueuePacket(rtc::CopyOnWriteBuffer(packet, length), absl::nullopt, true,
	transport);
	return true;
	}

	PacketReceiver::DeliveryStatus FakeNetworkPipe::DeliverPacket(
	MediaType media_type,
	rtc::CopyOnWriteBuffer packet,
	int64_t packet_time_us) {
	return EnqueuePacket(std::move(packet), absl::nullopt, false, media_type,
	packet_time_us)
	? PacketReceiver::DELIVERY_OK
	: PacketReceiver::DELIVERY_PACKET_ERROR;
	}

	void FakeNetworkPipe::SetClockOffset(int64_t offset_ms) {
	MutexLock lock(&config_lock_);
	clock_offset_ms_ = offset_ms;
	}

	FakeNetworkPipe::StoredPacket::StoredPacket(NetworkPacket&& packet)
	: packet(std::move(packet)) {}

	bool FakeNetworkPipe::EnqueuePacket(rtc::CopyOnWriteBuffer packet,
	absl::optional<PacketOptions> options,
	bool is_rtcp,
	MediaType media_type,
	absl::optional<int64_t> packet_time_us) {
	MutexLock lock(&process_lock_);
	int64_t time_now_us = clock_->TimeInMicroseconds();
	return EnqueuePacket(NetworkPacket(std::move(packet), time_now_us,
	time_now_us, options, is_rtcp, media_type,
	packet_time_us, nullptr));
	}

	bool FakeNetworkPipe::EnqueuePacket(rtc::CopyOnWriteBuffer packet,
	absl::optional<PacketOptions> options,
	bool is_rtcp,
	Transport* transport) {
	MutexLock lock(&process_lock_);
	int64_t time_now_us = clock_->TimeInMicroseconds();
	return EnqueuePacket(NetworkPacket(std::move(packet), time_now_us,
	time_now_us, options, is_rtcp,
	MediaType::ANY, absl::nullopt, transport));
	}

	bool FakeNetworkPipe::EnqueuePacket(NetworkPacket&& net_packet) {
	int64_t send_time_us = net_packet.send_time();
	size_t packet_size = net_packet.data_length();

	packets_in_flight_.emplace_back(StoredPacket(std::move(net_packet)));
	int64_t packet_id = reinterpret_cast<uint64_t>(&packets_in_flight_.back());
	bool sent = network_behavior_->EnqueuePacket(
	PacketInFlightInfo(packet_size, send_time_us, packet_id));

	if (!sent) {
	packets_in_flight_.pop_back();
	++dropped_packets_;
	}
	return sent;
	}

	float FakeNetworkPipe::PercentageLoss() {
	MutexLock lock(&process_lock_);
	if (sent_packets_ == 0)
	return 0;

	return static_cast<float>(dropped_packets_) /
	(sent_packets_ + dropped_packets_);
	}

	int FakeNetworkPipe::AverageDelay() {
	MutexLock lock(&process_lock_);
	if (sent_packets_ == 0)
	return 0;

	return static_cast<int>(total_packet_delay_us_ /
	(1000 * static_cast<int64_t>(sent_packets_)));
	}

	size_t FakeNetworkPipe::DroppedPackets() {
	MutexLock lock(&process_lock_);
	return dropped_packets_;
	}

	size_t FakeNetworkPipe::SentPackets() {
	MutexLock lock(&process_lock_);
	return sent_packets_;
	}

	void FakeNetworkPipe::Process() {
	int64_t time_now_us;
	std::queue<NetworkPacket> packets_to_deliver;
	{
	MutexLock lock(&process_lock_);
	time_now_us = clock_->TimeInMicroseconds();
	if (time_now_us - last_log_time_us_ > kLogIntervalMs * 1000) {
	int64_t queueing_delay_us = 0;
	if (!packets_in_flight_.empty())
	queueing_delay_us =
	time_now_us - packets_in_flight_.front().packet.send_time();

	RTC_LOG(LS_INFO) << "Network queue: " << queueing_delay_us / 1000
	<< " ms.";
	last_log_time_us_ = time_now_us;
	}

	std::vector<PacketDeliveryInfo> delivery_infos =
	network_behavior_->DequeueDeliverablePackets(time_now_us);
	for (auto& delivery_info : delivery_infos) {
	// In the common case where no reordering happens, find will return early
	// as the first packet will be a match.
	auto packet_it =
	std::find_if(packets_in_flight_.begin(), packets_in_flight_.end(),
	[&delivery_info](StoredPacket& packet_ref) {
	return reinterpret_cast<uint64_t>(&packet_ref) ==
	delivery_info.packet_id;
	});
	// Check that the packet is in the deque of packets in flight.
	RTC_CHECK(packet_it != packets_in_flight_.end());
	// Check that the packet is not already removed.
	RTC_DCHECK(!packet_it->removed);

	NetworkPacket packet = std::move(packet_it->packet);
	packet_it->removed = true;

	// Cleanup of removed packets at the beginning of the deque.
	while (!packets_in_flight_.empty() &&
	packets_in_flight_.front().removed) {
	packets_in_flight_.pop_front();
	}

	if (delivery_info.receive_time_us != PacketDeliveryInfo::kNotReceived) {
	int64_t added_delay_us =
	delivery_info.receive_time_us - packet.send_time();
	packet.IncrementArrivalTime(added_delay_us);
	packets_to_deliver.emplace(std::move(packet));
	// `time_now_us` might be later than when the packet should have
	// arrived, due to NetworkProcess being called too late. For stats, use
	// the time it should have been on the link.
	total_packet_delay_us_ += added_delay_us;
	++sent_packets_;
	} else {
	++dropped_packets_;
	}
	}
	}

	MutexLock lock(&config_lock_);
	while (!packets_to_deliver.empty()) {
	NetworkPacket packet = std::move(packets_to_deliver.front());
	packets_to_deliver.pop();
	DeliverNetworkPacket(&packet);
	}
	}

	void FakeNetworkPipe::DeliverNetworkPacket(NetworkPacket* packet) {
	Transport* transport = packet->transport();
	if (transport) {
	RTC_DCHECK(!receiver_);
	if (active_transports_.find(transport) == active_transports_.end()) {
	// Transport has been destroyed, ignore this packet.
	return;
	}
	if (packet->is_rtcp()) {
	transport->SendRtcp(packet->data(), packet->data_length());
	} else {
	transport->SendRtp(packet->data(), packet->data_length(),
	packet->packet_options());
	}
	} else if (receiver_) {
	int64_t packet_time_us = packet->packet_time_us().value_or(-1);
	if (packet_time_us != -1) {
	int64_t queue_time_us = packet->arrival_time() - packet->send_time();
	RTC_CHECK(queue_time_us >= 0);
	packet_time_us += queue_time_us;
	packet_time_us += (clock_offset_ms_ * 1000);
	}
	receiver_->DeliverPacket(packet->media_type(),
	std::move(*packet->raw_packet()), packet_time_us);
	}
	}

	absl::optional<int64_t> FakeNetworkPipe::TimeUntilNextProcess() {
	MutexLock lock(&process_lock_);
	absl::optional<int64_t> delivery_us = network_behavior_->NextDeliveryTimeUs();
	if (delivery_us) {
	int64_t delay_us = *delivery_us - clock_->TimeInMicroseconds();
	return std::max<int64_t>((delay_us + 500) / 1000, 0);
	}
	return absl::nullopt;
	}

	bool FakeNetworkPipe::HasReceiver() const {
	MutexLock lock(&config_lock_);
	return receiver_ != nullptr;
	}

	void FakeNetworkPipe::DeliverPacketWithLock(NetworkPacket* packet) {
	MutexLock lock(&config_lock_);
	DeliverNetworkPacket(packet);
	}

	void FakeNetworkPipe::ResetStats() {
	MutexLock lock(&process_lock_);
	dropped_packets_ = 0;
	sent_packets_ = 0;
	total_packet_delay_us_ = 0;
	}

	int64_t FakeNetworkPipe::GetTimeInMicroseconds() const {
	return clock_->TimeInMicroseconds();
	}

	} // namespace webrtc