quiche/recovery/congestion/bbr2/
init.rs

1// Copyright (C) 2022, Cloudflare, Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8//     * Redistributions of source code must retain the above copyright notice,
9//       this list of conditions and the following disclaimer.
10//
11//     * Redistributions in binary form must reproduce the above copyright
12//       notice, this list of conditions and the following disclaimer in the
13//       documentation and/or other materials provided with the distribution.
14//
15// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
16// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
19// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
24// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27use super::*;
28
29use rtt::INITIAL_RTT;
30
31use std::time::Instant;
32
33// BBR2 Functions at Initialization.
34//
35
36// 4.2.1.  Initialization
37pub fn bbr2_init(r: &mut Congestion) {
38    let now = Instant::now();
39
40    let bbr = &mut r.bbr2_state;
41    bbr.min_rtt = INITIAL_RTT;
42    bbr.min_rtt_stamp = now;
43    bbr.probe_rtt_done_stamp = None;
44    bbr.probe_rtt_round_done = false;
45    bbr.prior_cwnd = 0;
46    bbr.idle_restart = false;
47    bbr.extra_acked_interval_start = now;
48    bbr.extra_acked_delivered = 0;
49    bbr.bw_lo = u64::MAX;
50    bbr.bw_hi = u64::MAX;
51    bbr.inflight_lo = usize::MAX;
52    bbr.inflight_hi = usize::MAX;
53    bbr.probe_up_cnt = usize::MAX;
54
55    r.send_quantum = r.max_datagram_size;
56
57    per_loss::bbr2_reset_congestion_signals(r);
58    per_loss::bbr2_reset_lower_bounds(r);
59    bbr2_init_round_counting(r);
60    bbr2_init_full_pipe(r);
61    pacing::bbr2_init_pacing_rate(r);
62    bbr2_enter_startup(r);
63}
64
65// 4.5.1.  BBR.round_count: Tracking Packet-Timed Round Trips
66fn bbr2_init_round_counting(r: &mut Congestion) {
67    let bbr = &mut r.bbr2_state;
68
69    bbr.next_round_delivered = 0;
70    bbr.round_start = false;
71    bbr.round_count = 0;
72}
73
74// 4.3.1.1.  Startup Dynamics
75pub fn bbr2_enter_startup(r: &mut Congestion) {
76    let bbr = &mut r.bbr2_state;
77
78    bbr.state = BBR2StateMachine::Startup;
79    bbr.pacing_gain = STARTUP_PACING_GAIN;
80    bbr.cwnd_gain = STARTUP_CWND_GAIN;
81}
82
83// 4.3.1.2.  Exiting Startup Based on Bandwidth Plateau
84fn bbr2_init_full_pipe(r: &mut Congestion) {
85    let bbr = &mut r.bbr2_state;
86
87    bbr.filled_pipe = false;
88    bbr.full_bw = 0;
89    bbr.full_bw_count = 0;
90}
quiche/recovery/congestion/bbr2/init.rs

quiche/recovery/congestion/bbr2/
init.rs
