| // Copyright (c) 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // TCP cubic send side congestion algorithm, emulates the behavior of TCP cubic. |
| |
| #ifndef QUICHE_QUIC_CORE_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BYTES_H_ |
| #define QUICHE_QUIC_CORE_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BYTES_H_ |
| |
| #include <cstdint> |
| #include <string> |
| |
| #include "quiche/quic/core/congestion_control/cubic_bytes.h" |
| #include "quiche/quic/core/congestion_control/hybrid_slow_start.h" |
| #include "quiche/quic/core/congestion_control/prr_sender.h" |
| #include "quiche/quic/core/congestion_control/send_algorithm_interface.h" |
| #include "quiche/quic/core/quic_bandwidth.h" |
| #include "quiche/quic/core/quic_connection_stats.h" |
| #include "quiche/quic/core/quic_packets.h" |
| #include "quiche/quic/core/quic_time.h" |
| #include "quiche/quic/platform/api/quic_export.h" |
| |
| namespace quic { |
| |
| class RttStats; |
| |
| // Maximum window to allow when doing bandwidth resumption. |
| const QuicPacketCount kMaxResumptionCongestionWindow = 200; |
| |
| namespace test { |
| class TcpCubicSenderBytesPeer; |
| } // namespace test |
| |
| class QUIC_EXPORT_PRIVATE TcpCubicSenderBytes : public SendAlgorithmInterface { |
| public: |
| TcpCubicSenderBytes(const QuicClock* clock, const RttStats* rtt_stats, |
| bool reno, QuicPacketCount initial_tcp_congestion_window, |
| QuicPacketCount max_congestion_window, |
| QuicConnectionStats* stats); |
| TcpCubicSenderBytes(const TcpCubicSenderBytes&) = delete; |
| TcpCubicSenderBytes& operator=(const TcpCubicSenderBytes&) = delete; |
| ~TcpCubicSenderBytes() override; |
| |
| // Start implementation of SendAlgorithmInterface. |
| void SetFromConfig(const QuicConfig& config, |
| Perspective perspective) override; |
| void ApplyConnectionOptions( |
| const QuicTagVector& /*connection_options*/) override {} |
| void AdjustNetworkParameters(const NetworkParams& params) override; |
| void SetNumEmulatedConnections(int num_connections); |
| void SetInitialCongestionWindowInPackets( |
| QuicPacketCount congestion_window) override; |
| void OnConnectionMigration() override; |
| void OnCongestionEvent(bool rtt_updated, QuicByteCount prior_in_flight, |
| QuicTime event_time, |
| const AckedPacketVector& acked_packets, |
| const LostPacketVector& lost_packets) override; |
| void OnPacketSent(QuicTime sent_time, QuicByteCount bytes_in_flight, |
| QuicPacketNumber packet_number, QuicByteCount bytes, |
| HasRetransmittableData is_retransmittable) override; |
| void OnPacketNeutered(QuicPacketNumber /*packet_number*/) override {} |
| void OnRetransmissionTimeout(bool packets_retransmitted) override; |
| bool CanSend(QuicByteCount bytes_in_flight) override; |
| QuicBandwidth PacingRate(QuicByteCount bytes_in_flight) const override; |
| QuicBandwidth BandwidthEstimate() const override; |
| bool HasGoodBandwidthEstimateForResumption() const override { return false; } |
| QuicByteCount GetCongestionWindow() const override; |
| QuicByteCount GetSlowStartThreshold() const override; |
| CongestionControlType GetCongestionControlType() const override; |
| bool InSlowStart() const override; |
| bool InRecovery() const override; |
| std::string GetDebugState() const override; |
| void OnApplicationLimited(QuicByteCount bytes_in_flight) override; |
| void PopulateConnectionStats(QuicConnectionStats* /*stats*/) const override {} |
| // End implementation of SendAlgorithmInterface. |
| |
| QuicByteCount min_congestion_window() const { return min_congestion_window_; } |
| |
| protected: |
| // Compute the TCP Reno beta based on the current number of connections. |
| float RenoBeta() const; |
| |
| bool IsCwndLimited(QuicByteCount bytes_in_flight) const; |
| |
| // TODO(ianswett): Remove these and migrate to OnCongestionEvent. |
| void OnPacketAcked(QuicPacketNumber acked_packet_number, |
| QuicByteCount acked_bytes, QuicByteCount prior_in_flight, |
| QuicTime event_time); |
| void SetCongestionWindowFromBandwidthAndRtt(QuicBandwidth bandwidth, |
| QuicTime::Delta rtt); |
| void SetMinCongestionWindowInPackets(QuicPacketCount congestion_window); |
| void ExitSlowstart(); |
| void OnPacketLost(QuicPacketNumber packet_number, QuicByteCount lost_bytes, |
| QuicByteCount prior_in_flight); |
| void MaybeIncreaseCwnd(QuicPacketNumber acked_packet_number, |
| QuicByteCount acked_bytes, |
| QuicByteCount prior_in_flight, QuicTime event_time); |
| void HandleRetransmissionTimeout(); |
| |
| private: |
| friend class test::TcpCubicSenderBytesPeer; |
| |
| HybridSlowStart hybrid_slow_start_; |
| PrrSender prr_; |
| const RttStats* rtt_stats_; |
| QuicConnectionStats* stats_; |
| |
| // If true, Reno congestion control is used instead of Cubic. |
| const bool reno_; |
| |
| // Number of connections to simulate. |
| uint32_t num_connections_; |
| |
| // Track the largest packet that has been sent. |
| QuicPacketNumber largest_sent_packet_number_; |
| |
| // Track the largest packet that has been acked. |
| QuicPacketNumber largest_acked_packet_number_; |
| |
| // Track the largest packet number outstanding when a CWND cutback occurs. |
| QuicPacketNumber largest_sent_at_last_cutback_; |
| |
| // Whether to use 4 packets as the actual min, but pace lower. |
| bool min4_mode_; |
| |
| // Whether the last loss event caused us to exit slowstart. |
| // Used for stats collection of slowstart_packets_lost |
| bool last_cutback_exited_slowstart_; |
| |
| // When true, exit slow start with large cutback of congestion window. |
| bool slow_start_large_reduction_; |
| |
| // When true, use unity pacing instead of PRR. |
| bool no_prr_; |
| |
| CubicBytes cubic_; |
| |
| // ACK counter for the Reno implementation. |
| uint64_t num_acked_packets_; |
| |
| // Congestion window in bytes. |
| QuicByteCount congestion_window_; |
| |
| // Minimum congestion window in bytes. |
| QuicByteCount min_congestion_window_; |
| |
| // Maximum congestion window in bytes. |
| QuicByteCount max_congestion_window_; |
| |
| // Slow start congestion window in bytes, aka ssthresh. |
| QuicByteCount slowstart_threshold_; |
| |
| // Initial TCP congestion window in bytes. This variable can only be set when |
| // this algorithm is created. |
| const QuicByteCount initial_tcp_congestion_window_; |
| |
| // Initial maximum TCP congestion window in bytes. This variable can only be |
| // set when this algorithm is created. |
| const QuicByteCount initial_max_tcp_congestion_window_; |
| |
| // The minimum window when exiting slow start with large reduction. |
| QuicByteCount min_slow_start_exit_window_; |
| }; |
| |
| } // namespace quic |
| |
| #endif // QUICHE_QUIC_CORE_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BYTES_H_ |