| // Copyright 2013 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. |
| |
| #ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_ |
| #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_ |
| |
| #include <map> |
| #include <set> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/containers/hash_tables.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "net/base/linked_hash_map.h" |
| #include "net/quic/congestion_control/loss_detection_interface.h" |
| #include "net/quic/congestion_control/rtt_stats.h" |
| #include "net/quic/congestion_control/send_algorithm_interface.h" |
| #include "net/quic/crypto/cached_network_parameters.h" |
| #include "net/quic/quic_ack_notifier_manager.h" |
| #include "net/quic/quic_protocol.h" |
| #include "net/quic/quic_sustained_bandwidth_recorder.h" |
| #include "net/quic/quic_unacked_packet_map.h" |
| |
| namespace net { |
| |
| namespace test { |
| class QuicConnectionPeer; |
| class QuicSentPacketManagerPeer; |
| } // namespace test |
| |
| class QuicClock; |
| class QuicConfig; |
| struct QuicConnectionStats; |
| |
| // Class which tracks the set of packets sent on a QUIC connection and contains |
| // a send algorithm to decide when to send new packets. It keeps track of any |
| // retransmittable data associated with each packet. If a packet is |
| // retransmitted, it will keep track of each version of a packet so that if a |
| // previous transmission is acked, the data will not be retransmitted. |
| class NET_EXPORT_PRIVATE QuicSentPacketManager { |
| public: |
| // Interface which gets callbacks from the QuicSentPacketManager at |
| // interesting points. Implementations must not mutate the state of |
| // the packet manager or connection as a result of these callbacks. |
| class NET_EXPORT_PRIVATE DebugDelegate { |
| public: |
| virtual ~DebugDelegate() {} |
| |
| // Called when a spurious retransmission is detected. |
| virtual void OnSpuriousPacketRetransmission( |
| TransmissionType transmission_type, |
| QuicByteCount byte_size) {} |
| |
| virtual void OnIncomingAck( |
| const QuicAckFrame& ack_frame, |
| QuicTime ack_receive_time, |
| QuicPacketSequenceNumber largest_observed, |
| bool rtt_updated, |
| QuicPacketSequenceNumber least_unacked_sent_packet) {} |
| }; |
| |
| // Interface which gets callbacks from the QuicSentPacketManager when |
| // network-related state changes. Implementations must not mutate the |
| // state of the packet manager as a result of these callbacks. |
| class NET_EXPORT_PRIVATE NetworkChangeVisitor { |
| public: |
| virtual ~NetworkChangeVisitor() {} |
| |
| // Called when congestion window may have changed. |
| virtual void OnCongestionWindowChange() = 0; |
| |
| // Called when RTT may have changed, including when an RTT is read from |
| // the config. |
| virtual void OnRttChange() = 0; |
| }; |
| |
| // Struct to store the pending retransmission information. |
| struct PendingRetransmission { |
| PendingRetransmission(QuicPacketSequenceNumber sequence_number, |
| TransmissionType transmission_type, |
| const RetransmittableFrames& retransmittable_frames, |
| QuicSequenceNumberLength sequence_number_length) |
| : sequence_number(sequence_number), |
| transmission_type(transmission_type), |
| retransmittable_frames(retransmittable_frames), |
| sequence_number_length(sequence_number_length) { |
| } |
| |
| QuicPacketSequenceNumber sequence_number; |
| TransmissionType transmission_type; |
| const RetransmittableFrames& retransmittable_frames; |
| QuicSequenceNumberLength sequence_number_length; |
| }; |
| |
| QuicSentPacketManager(Perspective perspective, |
| const QuicClock* clock, |
| QuicConnectionStats* stats, |
| CongestionControlType congestion_control_type, |
| LossDetectionType loss_type, |
| bool is_secure); |
| virtual ~QuicSentPacketManager(); |
| |
| virtual void SetFromConfig(const QuicConfig& config); |
| |
| // Pass the CachedNetworkParameters to the send algorithm. |
| // Returns true if this changes the initial connection state. |
| bool ResumeConnectionState( |
| const CachedNetworkParameters& cached_network_params); |
| |
| void SetNumOpenStreams(size_t num_streams); |
| |
| void SetHandshakeConfirmed() { handshake_confirmed_ = true; } |
| |
| // Processes the incoming ack. |
| void OnIncomingAck(const QuicAckFrame& ack_frame, |
| QuicTime ack_receive_time); |
| |
| // Returns true if the non-FEC packet |sequence_number| is unacked. |
| bool IsUnacked(QuicPacketSequenceNumber sequence_number) const; |
| |
| // Requests retransmission of all unacked packets of |retransmission_type|. |
| // The behavior of this method depends on the value of |retransmission_type|: |
| // ALL_UNACKED_RETRANSMISSION - All unacked packets will be retransmitted. |
| // This can happen, for example, after a version negotiation packet has been |
| // received and all packets needs to be retransmitted with the new version. |
| // ALL_INITIAL_RETRANSMISSION - Only initially encrypted packets will be |
| // retransmitted. This can happen, for example, when a CHLO has been rejected |
| // and the previously encrypted data needs to be encrypted with a new key. |
| void RetransmitUnackedPackets(TransmissionType retransmission_type); |
| |
| // Retransmits the oldest pending packet there is still a tail loss probe |
| // pending. Invoked after OnRetransmissionTimeout. |
| bool MaybeRetransmitTailLossProbe(); |
| |
| // Removes the retransmittable frames from all unencrypted packets to ensure |
| // they don't get retransmitted. |
| void NeuterUnencryptedPackets(); |
| |
| // Returns true if the unacked packet |sequence_number| has retransmittable |
| // frames. This will only return false if the packet has been acked, if a |
| // previous transmission of this packet was ACK'd, or if this packet has been |
| // retransmitted as with different sequence number. |
| bool HasRetransmittableFrames(QuicPacketSequenceNumber sequence_number) const; |
| |
| // Returns true if there are pending retransmissions. |
| bool HasPendingRetransmissions() const; |
| |
| // Retrieves the next pending retransmission. You must ensure that |
| // there are pending retransmissions prior to calling this function. |
| PendingRetransmission NextPendingRetransmission(); |
| |
| bool HasUnackedPackets() const; |
| |
| // Returns the smallest sequence number of a serialized packet which has not |
| // been acked by the peer. |
| QuicPacketSequenceNumber GetLeastUnacked() const; |
| |
| // Called when we have sent bytes to the peer. This informs the manager both |
| // the number of bytes sent and if they were retransmitted. Returns true if |
| // the sender should reset the retransmission timer. |
| virtual bool OnPacketSent(SerializedPacket* serialized_packet, |
| QuicPacketSequenceNumber original_sequence_number, |
| QuicTime sent_time, |
| QuicByteCount bytes, |
| TransmissionType transmission_type, |
| HasRetransmittableData has_retransmittable_data); |
| |
| // Called when the retransmission timer expires. |
| virtual void OnRetransmissionTimeout(); |
| |
| // Calculate the time until we can send the next packet to the wire. |
| // Note 1: When kUnknownWaitTime is returned, there is no need to poll |
| // TimeUntilSend again until we receive an OnIncomingAckFrame event. |
| // Note 2: Send algorithms may or may not use |retransmit| in their |
| // calculations. |
| virtual QuicTime::Delta TimeUntilSend(QuicTime now, |
| HasRetransmittableData retransmittable); |
| |
| // Returns amount of time for delayed ack timer. |
| const QuicTime::Delta DelayedAckTime() const; |
| |
| // Returns the current delay for the retransmission timer, which may send |
| // either a tail loss probe or do a full RTO. Returns QuicTime::Zero() if |
| // there are no retransmittable packets. |
| const QuicTime GetRetransmissionTime() const; |
| |
| const RttStats* GetRttStats() const; |
| |
| // Returns the estimated bandwidth calculated by the congestion algorithm. |
| QuicBandwidth BandwidthEstimate() const; |
| |
| // Returns true if the current instantaneous bandwidth estimate is reliable. |
| bool HasReliableBandwidthEstimate() const; |
| |
| const QuicSustainedBandwidthRecorder& SustainedBandwidthRecorder() const; |
| |
| // Returns the size of the current congestion window in number of |
| // kDefaultTCPMSS-sized segments. Note, this is not the *available* window. |
| // Some send algorithms may not use a congestion window and will return 0. |
| QuicPacketCount GetCongestionWindowInTcpMss() const; |
| |
| // Returns the number of packets of length |max_packet_length| which fit in |
| // the current congestion window. More packets may end up in flight if the |
| // congestion window has been recently reduced, of if non-full packets are |
| // sent. |
| QuicPacketCount EstimateMaxPacketsInFlight( |
| QuicByteCount max_packet_length) const; |
| |
| // Returns the size of the slow start congestion window in nume of 1460 byte |
| // TCP segments, aka ssthresh. Some send algorithms do not define a slow |
| // start threshold and will return 0. |
| QuicPacketCount GetSlowStartThresholdInTcpMss() const; |
| |
| // Called by the connection every time it receives a serialized packet. |
| void OnSerializedPacket(const SerializedPacket& serialized_packet); |
| |
| // No longer retransmit data for |stream_id|. |
| void CancelRetransmissionsForStream(QuicStreamId stream_id); |
| |
| // Enables pacing if it has not already been enabled. |
| void EnablePacing(); |
| |
| bool using_pacing() const { return using_pacing_; } |
| |
| void set_debug_delegate(DebugDelegate* debug_delegate) { |
| debug_delegate_ = debug_delegate; |
| } |
| |
| QuicPacketSequenceNumber largest_observed() const { |
| return unacked_packets_.largest_observed(); |
| } |
| |
| QuicPacketSequenceNumber least_packet_awaited_by_peer() { |
| return least_packet_awaited_by_peer_; |
| } |
| |
| void set_network_change_visitor(NetworkChangeVisitor* visitor) { |
| DCHECK(!network_change_visitor_); |
| DCHECK(visitor); |
| network_change_visitor_ = visitor; |
| } |
| |
| // Used in Chromium, but not in the server. |
| size_t consecutive_rto_count() const { |
| return consecutive_rto_count_; |
| } |
| |
| // Used in Chromium, but not in the server. |
| size_t consecutive_tlp_count() const { |
| return consecutive_tlp_count_; |
| } |
| |
| private: |
| friend class test::QuicConnectionPeer; |
| friend class test::QuicSentPacketManagerPeer; |
| |
| // The retransmission timer is a single timer which switches modes depending |
| // upon connection state. |
| enum RetransmissionTimeoutMode { |
| // A conventional TCP style RTO. |
| RTO_MODE, |
| // A tail loss probe. By default, QUIC sends up to two before RTOing. |
| TLP_MODE, |
| // Retransmission of handshake packets prior to handshake completion. |
| HANDSHAKE_MODE, |
| // Re-invoke the loss detection when a packet is not acked before the |
| // loss detection algorithm expects. |
| LOSS_MODE, |
| }; |
| |
| typedef linked_hash_map<QuicPacketSequenceNumber, |
| TransmissionType> PendingRetransmissionMap; |
| |
| // Updates the least_packet_awaited_by_peer. |
| void UpdatePacketInformationReceivedByPeer(const QuicAckFrame& ack_frame); |
| |
| // Process the incoming ack looking for newly ack'd data packets. |
| void HandleAckForSentPackets(const QuicAckFrame& ack_frame); |
| |
| // Returns the current retransmission mode. |
| RetransmissionTimeoutMode GetRetransmissionMode() const; |
| |
| // Retransmits all crypto stream packets. |
| void RetransmitCryptoPackets(); |
| |
| // Retransmits two packets for an RTO and removes any non-retransmittable |
| // packets from flight. |
| void RetransmitRtoPackets(); |
| |
| // Returns the timer for retransmitting crypto handshake packets. |
| const QuicTime::Delta GetCryptoRetransmissionDelay() const; |
| |
| // Returns the timer for a new tail loss probe. |
| const QuicTime::Delta GetTailLossProbeDelay() const; |
| |
| // Returns the retransmission timeout, after which a full RTO occurs. |
| const QuicTime::Delta GetRetransmissionDelay() const; |
| |
| // Update the RTT if the ack is for the largest acked sequence number. |
| // Returns true if the rtt was updated. |
| bool MaybeUpdateRTT(const QuicAckFrame& ack_frame, |
| const QuicTime& ack_receive_time); |
| |
| // Invokes the loss detection algorithm and loses and retransmits packets if |
| // necessary. |
| void InvokeLossDetection(QuicTime time); |
| |
| // Invokes OnCongestionEvent if |rtt_updated| is true, there are pending acks, |
| // or pending losses. Clears pending acks and pending losses afterwards. |
| // |bytes_in_flight| is the number of bytes in flight before the losses or |
| // acks. |
| void MaybeInvokeCongestionEvent(bool rtt_updated, |
| QuicByteCount bytes_in_flight); |
| |
| // Marks |sequence_number| as having been revived by the peer, but not |
| // received, so the packet remains pending if it is and the congestion control |
| // does not consider the packet acked. |
| void MarkPacketRevived(QuicPacketSequenceNumber sequence_number, |
| QuicTime::Delta delta_largest_observed); |
| |
| // Removes the retransmittability and pending properties from the packet at |
| // |it| due to receipt by the peer. Returns an iterator to the next remaining |
| // unacked packet. |
| void MarkPacketHandled(QuicPacketSequenceNumber sequence_number, |
| const TransmissionInfo& info, |
| QuicTime::Delta delta_largest_observed); |
| |
| // Request that |sequence_number| be retransmitted after the other pending |
| // retransmissions. Does not add it to the retransmissions if it's already |
| // a pending retransmission. |
| void MarkForRetransmission(QuicPacketSequenceNumber sequence_number, |
| TransmissionType transmission_type); |
| |
| // Notify observers about spurious retransmits. |
| void RecordSpuriousRetransmissions( |
| const SequenceNumberList& all_transmissions, |
| QuicPacketSequenceNumber acked_sequence_number); |
| |
| // Returns true if the client is sending or the server has received a |
| // connection option. |
| bool HasClientSentConnectionOption(const QuicConfig& config, |
| QuicTag tag) const; |
| |
| // Newly serialized retransmittable and fec packets are added to this map, |
| // which contains owning pointers to any contained frames. If a packet is |
| // retransmitted, this map will contain entries for both the old and the new |
| // packet. The old packet's retransmittable frames entry will be nullptr, |
| // while the new packet's entry will contain the frames to retransmit. |
| // If the old packet is acked before the new packet, then the old entry will |
| // be removed from the map and the new entry's retransmittable frames will be |
| // set to nullptr. |
| QuicUnackedPacketMap unacked_packets_; |
| |
| // Pending retransmissions which have not been packetized and sent yet. |
| PendingRetransmissionMap pending_retransmissions_; |
| |
| // Tracks if the connection was created by the server or the client. |
| Perspective perspective_; |
| |
| // An AckNotifier can register to be informed when ACKs have been received for |
| // all packets that a given block of data was sent in. The AckNotifierManager |
| // maintains the currently active notifiers. |
| AckNotifierManager ack_notifier_manager_; |
| |
| const QuicClock* clock_; |
| QuicConnectionStats* stats_; |
| DebugDelegate* debug_delegate_; |
| NetworkChangeVisitor* network_change_visitor_; |
| const QuicPacketCount initial_congestion_window_; |
| RttStats rtt_stats_; |
| scoped_ptr<SendAlgorithmInterface> send_algorithm_; |
| scoped_ptr<LossDetectionInterface> loss_algorithm_; |
| bool n_connection_simulation_; |
| |
| // Receiver side buffer in bytes. |
| QuicByteCount receive_buffer_bytes_; |
| |
| // Least sequence number which the peer is still waiting for. |
| QuicPacketSequenceNumber least_packet_awaited_by_peer_; |
| |
| // Tracks the first RTO packet. If any packet before that packet gets acked, |
| // it indicates the RTO was spurious and should be reversed(F-RTO). |
| QuicPacketSequenceNumber first_rto_transmission_; |
| // Number of times the RTO timer has fired in a row without receiving an ack. |
| size_t consecutive_rto_count_; |
| // Number of times the tail loss probe has been sent. |
| size_t consecutive_tlp_count_; |
| // Number of times the crypto handshake has been retransmitted. |
| size_t consecutive_crypto_retransmission_count_; |
| // Number of pending transmissions of TLP, RTO, or crypto packets. |
| size_t pending_timer_transmission_count_; |
| // Maximum number of tail loss probes to send before firing an RTO. |
| size_t max_tail_loss_probes_; |
| bool using_pacing_; |
| // If true, use the new RTO with loss based CWND reduction instead of the send |
| // algorithms's OnRetransmissionTimeout to reduce the congestion window. |
| bool use_new_rto_; |
| |
| // Vectors packets acked and lost as a result of the last congestion event. |
| SendAlgorithmInterface::CongestionVector packets_acked_; |
| SendAlgorithmInterface::CongestionVector packets_lost_; |
| |
| // Set to true after the crypto handshake has successfully completed. After |
| // this is true we no longer use HANDSHAKE_MODE, and further frames sent on |
| // the crypto stream (i.e. SCUP messages) are treated like normal |
| // retransmittable frames. |
| bool handshake_confirmed_; |
| |
| // Records bandwidth from server to client in normal operation, over periods |
| // of time with no loss events. |
| QuicSustainedBandwidthRecorder sustained_bandwidth_recorder_; |
| |
| DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_ |