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Diffstat (limited to 'lib/ngtcp2_bbr.h')
| -rw-r--r-- | lib/ngtcp2_bbr.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/lib/ngtcp2_bbr.h b/lib/ngtcp2_bbr.h new file mode 100644 index 0000000..7311f05 --- /dev/null +++ b/lib/ngtcp2_bbr.h @@ -0,0 +1,156 @@ +/* + * ngtcp2 + * + * Copyright (c) 2021 ngtcp2 contributors + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE + * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION + * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ +#ifndef NGTCP2_BBR_H +#define NGTCP2_BBR_H + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif /* HAVE_CONFIG_H */ + +#include <ngtcp2/ngtcp2.h> + +#include "ngtcp2_cc.h" +#include "ngtcp2_window_filter.h" + +typedef struct ngtcp2_rst ngtcp2_rst; + +typedef enum ngtcp2_bbr_state { + NGTCP2_BBR_STATE_STARTUP, + NGTCP2_BBR_STATE_DRAIN, + NGTCP2_BBR_STATE_PROBE_BW, + NGTCP2_BBR_STATE_PROBE_RTT, +} ngtcp2_bbr_state; + +/* + * ngtcp2_bbr_cc is BBR congestion controller, described in + * https://tools.ietf.org/html/draft-cardwell-iccrg-bbr-congestion-control-00 + */ +typedef struct ngtcp2_bbr_cc { + ngtcp2_cc_base ccb; + + /* The max filter used to estimate BBR.BtlBw. */ + ngtcp2_window_filter btl_bw_filter; + uint64_t initial_cwnd; + ngtcp2_rst *rst; + ngtcp2_rand rand; + ngtcp2_rand_ctx rand_ctx; + + /* BBR variables */ + + /* The dynamic gain factor used to scale BBR.BtlBw to + produce BBR.pacing_rate. */ + double pacing_gain; + /* The dynamic gain factor used to scale the estimated BDP to produce a + congestion window (cwnd). */ + double cwnd_gain; + uint64_t full_bw; + /* packet.delivered value denoting the end of a packet-timed round trip. */ + uint64_t next_round_delivered; + /* Count of packet-timed round trips. */ + uint64_t round_count; + uint64_t prior_cwnd; + /* target_cwnd is the upper bound on the volume of data BBR + allows in flight. */ + uint64_t target_cwnd; + /* BBR's estimated bottleneck bandwidth available to the + transport flow, estimated from the maximum delivery rate sample in a + sliding window. */ + uint64_t btl_bw; + /* BBR's estimated two-way round-trip propagation delay of + the path, estimated from the windowed minimum recent round-trip delay + sample. */ + ngtcp2_duration rt_prop; + /* The wall clock time at which the current BBR.RTProp + sample was obtained. */ + ngtcp2_tstamp rtprop_stamp; + ngtcp2_tstamp cycle_stamp; + ngtcp2_tstamp probe_rtt_done_stamp; + /* congestion_recovery_start_ts is the time when congestion recovery + period started.*/ + ngtcp2_tstamp congestion_recovery_start_ts; + uint64_t congestion_recovery_next_round_delivered; + size_t full_bw_count; + size_t cycle_index; + ngtcp2_bbr_state state; + /* A boolean that records whether BBR estimates that it has ever fully + utilized its available bandwidth ("filled the pipe"). */ + int filled_pipe; + /* A boolean that BBR sets to true once per packet-timed round trip, + on ACKs that advance BBR.round_count. */ + int round_start; + int rtprop_expired; + int idle_restart; + int packet_conservation; + int probe_rtt_round_done; + /* in_loss_recovery becomes nonzero when BBR enters loss recovery + period. */ + int in_loss_recovery; +} ngtcp2_bbr_cc; + +int ngtcp2_cc_bbr_cc_init(ngtcp2_cc *cc, ngtcp2_log *log, + ngtcp2_conn_stat *cstat, ngtcp2_rst *rst, + ngtcp2_tstamp initial_ts, ngtcp2_rand rand, + const ngtcp2_rand_ctx *rand_ctx, + const ngtcp2_mem *mem); + +void ngtcp2_cc_bbr_cc_free(ngtcp2_cc *cc, const ngtcp2_mem *mem); + +void ngtcp2_bbr_cc_init(ngtcp2_bbr_cc *bbr_cc, ngtcp2_conn_stat *cstat, + ngtcp2_rst *rst, ngtcp2_tstamp initial_ts, + ngtcp2_rand rand, const ngtcp2_rand_ctx *rand_ctx, + ngtcp2_log *log); + +void ngtcp2_bbr_cc_free(ngtcp2_bbr_cc *cc); + +void ngtcp2_cc_bbr_cc_on_pkt_acked(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + const ngtcp2_cc_pkt *pkt, ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_congestion_event(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + ngtcp2_tstamp sent_ts, ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_on_spurious_congestion(ngtcp2_cc *ccx, + ngtcp2_conn_stat *cstat, + ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_on_persistent_congestion(ngtcp2_cc *cc, + ngtcp2_conn_stat *cstat, + ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_on_ack_recv(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + const ngtcp2_cc_ack *ack, ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_on_pkt_sent(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + const ngtcp2_cc_pkt *pkt); + +void ngtcp2_cc_bbr_cc_new_rtt_sample(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_reset(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + ngtcp2_tstamp ts); + +void ngtcp2_cc_bbr_cc_event(ngtcp2_cc *cc, ngtcp2_conn_stat *cstat, + ngtcp2_cc_event_type event, ngtcp2_tstamp ts); + +#endif /* NGTCP2_BBR_H */ |