quiche/recovery/congestion/bbr/per_transmit.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
29// BBR Functions when trasmitting packets.
30//
31pub fn bbr_on_transmit(r: &mut Congestion, bytes_in_flight: usize) {
32 bbr_handle_restart_from_idle(r, bytes_in_flight);
33}
34
35// 4.3.4.4. Restarting From Idle
36fn bbr_handle_restart_from_idle(r: &mut Congestion, bytes_in_flight: usize) {
37 if bytes_in_flight == 0 && r.delivery_rate.app_limited() {
38 r.bbr_state.idle_restart = true;
39
40 if r.bbr_state.state == BBRStateMachine::ProbeBW {
41 pacing::bbr_set_pacing_rate_with_gain(r, 1.0);
42 }
43 }
44}