tor_proto/congestion/
vegas.rs

1//! Implementation of the Tor Vegas congestion control algorithm.
2//!
3//! This is used by the circuit reactor in order to decide when to send data and SENDMEs.
4//!
5//! Spec: prop324 section 3.3 (TOR_VEGAS)
6
7use super::{
8    CongestionControlAlgorithm, CongestionSignals, CongestionWindow, State,
9    params::{Algorithm, VegasParams},
10    rtt::RoundtripTimeEstimator,
11};
12use crate::Result;
13
14use tor_error::{error_report, internal};
15
16/// Bandwidth-Delay Product (BDP) estimator.
17///
18/// Spec: prop324 section 3.1 (BDP_ESTIMATION).
19#[derive(Clone, Debug, Default)]
20pub(crate) struct BdpEstimator {
21    /// The BDP value of this estimator.
22    bdp: u32,
23}
24
25impl BdpEstimator {
26    /// Return the current BDP value.
27    fn get(&self) -> u32 {
28        self.bdp
29    }
30
31    /// Update the estimator with the given congestion window, RTT estimator and any condition
32    /// signals that we are currently experiencing.
33    ///
34    /// C-tor: congestion_control_update_circuit_bdp() in congestion_control_common.c
35    fn update(
36        &mut self,
37        cwnd: &CongestionWindow,
38        rtt: &RoundtripTimeEstimator,
39        signals: &CongestionSignals,
40    ) {
41        // Stalled clock means our RTT value is invalid so set the BDP to the cwnd.
42        if rtt.clock_stalled() {
43            self.bdp = if signals.channel_blocked {
44                // Set the BDP to the cwnd minus the outbound queue size, capping it to the minimum
45                // cwnd.
46                cwnd.get()
47                    .saturating_sub(signals.channel_outbound_size)
48                    .max(cwnd.min())
49            } else {
50                cwnd.get()
51            };
52        } else {
53            // Congestion window based BDP will respond to changes in RTT only, and is relative to
54            // cwnd growth. It is useful for correcting for BDP overestimation, but if BDP is
55            // higher than the current cwnd, it will underestimate it.
56            //
57            // To clarify this is equivalent to: cwnd * min_rtt / ewma_rtt.
58            let min_rtt_usec = rtt.min_rtt_usec().unwrap_or(u32::MAX);
59            let ewma_rtt_usec = rtt.ewma_rtt_usec().unwrap_or(u32::MAX);
60            self.bdp = cwnd
61                .get()
62                .saturating_mul(min_rtt_usec)
63                .saturating_div(ewma_rtt_usec);
64        }
65    }
66}
67
68/// Congestion control Vegas algorithm.
69///
70/// TCP Vegas control algorithm estimates the queue lengths at relays by subtracting the current
71/// BDP estimate from the current congestion window.
72///
73/// This object implements CongestionControlAlgorithm trait used by the ['CongestionControl'].
74///
75/// Spec: prop324 section 3.3 (TOR_VEGAS)
76/// C-tor: Split between congestion_control_vegas.c and the congestion_control_t struct.
77#[derive(Clone, Debug)]
78pub(crate) struct Vegas {
79    /// Congestion control parameters.
80    params: VegasParams,
81    /// Bandwidth delay product.
82    /// C-tor: "bdp"
83    bdp: BdpEstimator,
84    /// Congestion window.
85    /// C-tor: "cwnd", "cwnd_inc_pct_ss", "cwnd_inc", "cwnd_min", "cwnd_inc_rate", "cwnd_full",
86    cwnd: CongestionWindow,
87    /// Number of cells expected before we send a SENDME resulting in more data.
88    num_cell_until_sendme: u32,
89    /// The number of SENDME until we will acknowledge a congestion event again.
90    /// C-tor: "next_cc_event"
91    num_sendme_until_cwnd_update: u32,
92    /// Counts down until we process a cwnd worth of SENDME acks. Used to track full cwnd status.
93    /// C-tor: "next_cwnd_event"
94    num_sendme_per_cwnd: u32,
95    /// Number of cells in-flight (sent but awaiting SENDME ack).
96    /// C-tor: "inflight"
97    num_inflight: u32,
98    /// Indicate if we noticed we were blocked on channel during an algorithm run. This is used to
99    /// notice a change from blocked to non-blocked in order to reset the num_sendme_per_cwnd.
100    /// C-tor: "blocked_chan"
101    is_blocked_on_chan: bool,
102}
103
104impl Vegas {
105    /// Create a new [`Vegas`] from the specified parameters, state, and cwnd.
106    pub(crate) fn new(params: VegasParams, state: &State, cwnd: CongestionWindow) -> Self {
107        Self {
108            params,
109            bdp: BdpEstimator::default(),
110            num_cell_until_sendme: cwnd.sendme_inc(),
111            num_inflight: 0,
112            num_sendme_per_cwnd: 0,
113            num_sendme_until_cwnd_update: cwnd.update_rate(state),
114            cwnd,
115            is_blocked_on_chan: false,
116        }
117    }
118}
119
120impl CongestionControlAlgorithm for Vegas {
121    fn uses_stream_sendme(&self) -> bool {
122        // Not allowed as in Vegas doesn't need them.
123        false
124    }
125
126    fn uses_xon_xoff(&self) -> bool {
127        true
128    }
129
130    fn is_next_cell_sendme(&self) -> bool {
131        // Matching inflight number to the SENDME increment, time to send a SENDME. Contrary to
132        // C-tor, this is called after num_inflight is incremented.
133        self.num_inflight.is_multiple_of(self.cwnd.sendme_inc())
134    }
135
136    fn can_send(&self) -> bool {
137        self.num_inflight < self.cwnd.get()
138    }
139
140    fn cwnd(&self) -> Option<CongestionWindow> {
141        Some(self.cwnd)
142    }
143
144    /// Called when a SENDME cell is received.
145    ///
146    /// This is where the Vegas algorithm magic happens entirely. For every SENDME we get, the
147    /// entire state is updated which usually result in the congestion window being changed.
148    ///
149    /// An error is returned if there is a protocol violation with regards to flow or congestion
150    /// control.
151    ///
152    /// Spec: prop324 section 3.3 (TOR_VEGAS)
153    /// C-tor: congestion_control_vegas_process_sendme() in congestion_control_vegas.c
154    fn sendme_received(
155        &mut self,
156        state: &mut State,
157        rtt: &mut RoundtripTimeEstimator,
158        signals: CongestionSignals,
159    ) -> Result<()> {
160        // Update the countdown until we need to update the congestion window.
161        self.num_sendme_until_cwnd_update = self.num_sendme_until_cwnd_update.saturating_sub(1);
162        // We just got a SENDME so decrement the amount of expected SENDMEs for a cwnd.
163        self.num_sendme_per_cwnd = self.num_sendme_per_cwnd.saturating_sub(1);
164
165        // From here, C-tor proceeds to update the RTT and BDP (circuit estimates). The RTT is
166        // updated before this is called and so the "rtt" object is up to date with the latest. As
167        // for the BDP, we update it now. See C-tor congestion_control_update_circuit_estimates().
168
169        // Update the BDP estimator even if the RTT estimator is not ready. If that is the case,
170        // we'll estimate a BDP value to bootstrap.
171        self.bdp.update(&self.cwnd, rtt, &signals);
172
173        // Evaluate if we changed state on the blocked chan. This is done in the BDP update function
174        // in C-tor. Instead, we do it now after the update of the BDP value.
175        if rtt.is_ready() {
176            if signals.channel_blocked {
177                // Going from non blocked to block, it is an immediate congestion signal so reset the
178                // number of sendme per cwnd because we are about to reevaluate it.
179                if !self.is_blocked_on_chan {
180                    self.num_sendme_until_cwnd_update = 0;
181                }
182            } else {
183                // Going from blocked to non block, need to reevaluate the cwnd and so reset num
184                // sendme.
185                if self.is_blocked_on_chan {
186                    self.num_sendme_until_cwnd_update = 0;
187                }
188            }
189        }
190        self.is_blocked_on_chan = signals.channel_blocked;
191
192        // Only run the algorithm if the RTT estimator is ready or we have a blocked channel.
193        if !rtt.is_ready() && !self.is_blocked_on_chan {
194            // The inflight value can never be below a sendme_inc because every time a cell is sent,
195            // inflight is incremented and we only end up decrementing if we receive a valid
196            // authenticated SENDME which is always after the sendme_inc value that we get that.
197            debug_assert!(self.num_inflight >= self.cwnd.sendme_inc());
198            self.num_inflight = self.num_inflight.saturating_sub(self.cwnd.sendme_inc());
199            return Ok(());
200        }
201
202        // The queue use is the amount in which our cwnd is above BDP;
203        // if it is below, then 0 queue use.
204        let queue_use = self.cwnd.get().saturating_sub(self.bdp.get());
205
206        // Evaluate if the congestion window has became full or not.
207        self.cwnd.eval_fullness(
208            self.num_inflight,
209            self.params.cwnd_full_gap(),
210            self.params.cwnd_full_min_pct().as_percent(),
211        );
212
213        // Spec: See the pseudocode of TOR_VEGAS with RFC3742
214        if state.in_slow_start() {
215            if queue_use < self.params.cell_in_queue_params().gamma() && !self.is_blocked_on_chan {
216                // If the congestion window is not fully in use, skip any increment in slow start.
217                if self.cwnd.is_full() {
218                    // This is the "Limited Slow Start" increment.
219                    let inc = self
220                        .cwnd
221                        .rfc3742_ss_inc(self.params.cell_in_queue_params().ss_cwnd_cap());
222
223                    // Check if inc is less than what we would do in steady-state avoidance. Note
224                    // that this is likely never to happen in practice. If so, exit slow start.
225                    if (inc * self.cwnd.sendme_per_cwnd())
226                        <= (self.cwnd.increment() * self.cwnd.increment_rate())
227                    {
228                        *state = State::Steady;
229                    }
230                }
231            } else {
232                // Congestion signal: Set cwnd to gamma threshold
233                self.cwnd
234                    .set(self.bdp.get() + self.params.cell_in_queue_params().gamma());
235                // Exit slow start due to congestion signal.
236                *state = State::Steady;
237            }
238
239            // Max the window and exit slow start.
240            if self.cwnd.get() >= self.params.ss_cwnd_max() {
241                self.cwnd.set(self.params.ss_cwnd_max());
242                *state = State::Steady;
243            }
244        } else if self.num_sendme_until_cwnd_update == 0 {
245            // Once in steady state, we only update once per window.
246            if queue_use > self.params.cell_in_queue_params().delta() {
247                // Above delta threshold, drop cwnd down to the delta.
248                self.cwnd.set(
249                    self.bdp.get() + self.params.cell_in_queue_params().delta()
250                        - self.cwnd.increment(),
251                );
252            } else if queue_use > self.params.cell_in_queue_params().beta()
253                || self.is_blocked_on_chan
254            {
255                // Congestion signal: Above beta or if channel is blocked, decrement window.
256                self.cwnd.dec();
257            } else if self.cwnd.is_full() && queue_use < self.params.cell_in_queue_params().alpha()
258            {
259                // Congestion window is full and the queue usage is below alpha, increment.
260                self.cwnd.inc();
261            }
262        }
263
264        // Reset our counters if they reached their bottom.
265        if self.num_sendme_until_cwnd_update == 0 {
266            self.num_sendme_until_cwnd_update = self.cwnd.update_rate(state);
267        }
268        if self.num_sendme_per_cwnd == 0 {
269            self.num_sendme_per_cwnd = self.cwnd.sendme_per_cwnd();
270        }
271
272        // Decide if enough time has passed to reset the cwnd.
273        if self.params.cwnd_full_per_cwnd() != 0 {
274            if self.num_sendme_per_cwnd == self.cwnd.sendme_per_cwnd() {
275                self.cwnd.reset_full();
276            }
277        } else if self.num_sendme_until_cwnd_update == self.cwnd.update_rate(state) {
278            self.cwnd.reset_full();
279        }
280
281        // Finally, update the inflight now that we have a SENDME.
282        self.num_inflight = self.num_inflight.saturating_sub(self.cwnd.sendme_inc());
283        Ok(())
284    }
285
286    fn sendme_sent(&mut self) -> Result<()> {
287        // SENDME is on the wire, set our counter until next one.
288        self.num_cell_until_sendme = self.cwnd.sendme_inc();
289        Ok(())
290    }
291
292    fn data_received(&mut self) -> Result<bool> {
293        if self.num_cell_until_sendme == 0 {
294            // This is not a protocol violation, it is a code flow error and so don't close the
295            // circuit by sending back an Error. Catching this prevents from sending two SENDMEs
296            // back to back. We recover from this but scream very loudly.
297            error_report!(internal!("Congestion control unexptected data cell"), "");
298            return Ok(false);
299        }
300
301        // Decrement the expected window.
302        self.num_cell_until_sendme = self.num_cell_until_sendme.saturating_sub(1);
303
304        // Reaching zero, lets inform the caller a SENDME needs to be sent. This counter is reset
305        // when the SENDME is actually sent.
306        Ok(self.num_cell_until_sendme == 0)
307    }
308
309    fn data_sent(&mut self) -> Result<()> {
310        // This can be above cwnd because that cwnd can shrink while we are still sending data.
311        self.num_inflight = self.num_inflight.saturating_add(1);
312        Ok(())
313    }
314
315    #[cfg(feature = "conflux")]
316    fn inflight(&self) -> Option<u32> {
317        Some(self.num_inflight)
318    }
319
320    #[cfg(test)]
321    fn send_window(&self) -> u32 {
322        self.cwnd.get()
323    }
324
325    fn algorithm(&self) -> Algorithm {
326        Algorithm::Vegas(self.params)
327    }
328}
329
330#[cfg(test)]
331pub(crate) mod test {
332    // @@ begin test lint list maintained by maint/add_warning @@
333    #![allow(clippy::bool_assert_comparison)]
334    #![allow(clippy::clone_on_copy)]
335    #![allow(clippy::dbg_macro)]
336    #![allow(clippy::mixed_attributes_style)]
337    #![allow(clippy::print_stderr)]
338    #![allow(clippy::print_stdout)]
339    #![allow(clippy::single_char_pattern)]
340    #![allow(clippy::unwrap_used)]
341    #![allow(clippy::unchecked_time_subtraction)]
342    #![allow(clippy::useless_vec)]
343    #![allow(clippy::needless_pass_by_value)]
344    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
345
346    use std::collections::VecDeque;
347    use tor_units::Percentage;
348    use web_time_compat::{Duration, Instant, InstantExt};
349
350    use super::*;
351    use crate::congestion::{
352        params::VegasParamsBuilder,
353        test_utils::{new_cwnd, new_rtt_estimator},
354    };
355
356    impl Vegas {
357        /// Set the number of inflight cell.
358        pub(crate) fn set_inflight(&mut self, v: u32) {
359            self.num_inflight = v;
360        }
361        /// Return the state of the blocked on chan flag.
362        fn is_blocked_on_chan(&self) -> bool {
363            self.is_blocked_on_chan
364        }
365        /// Set the state of the blocked on chan flag.
366        fn set_is_blocked_on_chan(&mut self, v: bool) {
367            self.is_blocked_on_chan = v;
368        }
369    }
370
371    /// The test vector parameters. They have the exact same name as in C-tor in order to help
372    /// matching them and avoid confusion.
373    #[derive(Debug)]
374    struct TestVectorParams {
375        // Inbound parameters.
376        sent_usec_in: u64,
377        got_sendme_usec_in: u64,
378        or_conn_blocked_in: bool,
379        inflight_in: u32,
380        // Expected outbound parameters.
381        ewma_rtt_usec_out: u32,
382        min_rtt_usec_out: u32,
383        cwnd_out: u32,
384        in_slow_start_out: bool,
385        cwnd_full_out: bool,
386        blocked_chan_out: bool,
387    }
388
389    impl From<[u32; 10]> for TestVectorParams {
390        fn from(arr: [u32; 10]) -> Self {
391            Self {
392                sent_usec_in: u64::from(arr[0]),
393                got_sendme_usec_in: u64::from(arr[1]),
394                or_conn_blocked_in: arr[2] == 1,
395                inflight_in: arr[3],
396                ewma_rtt_usec_out: arr[4],
397                min_rtt_usec_out: arr[5],
398                cwnd_out: arr[6],
399                in_slow_start_out: arr[7] == 1,
400                cwnd_full_out: arr[8] == 1,
401                blocked_chan_out: arr[9] == 1,
402            }
403        }
404    }
405
406    struct VegasTest {
407        params: VecDeque<TestVectorParams>,
408        rtt: RoundtripTimeEstimator,
409        state: State,
410        vegas: Vegas,
411    }
412
413    impl VegasTest {
414        fn new(vec: Vec<[u32; 10]>) -> Self {
415            let mut params = VecDeque::new();
416            for values in vec {
417                params.push_back(values.into());
418            }
419            let state = State::default();
420            Self {
421                params,
422                rtt: new_rtt_estimator(),
423                vegas: Vegas::new(build_vegas_params(), &state, new_cwnd()),
424                state,
425            }
426        }
427
428        fn run_once(&mut self, p: &TestVectorParams) {
429            eprintln!("Testing vector: {:?}", p);
430            // Set the inflight and channel blocked value from the test vector.
431            self.vegas.set_inflight(p.inflight_in);
432            self.vegas.set_is_blocked_on_chan(p.or_conn_blocked_in);
433
434            let now = Instant::get();
435            self.rtt
436                .expect_sendme(now + Duration::from_micros(p.sent_usec_in));
437            let ret = self.rtt.update(
438                now + Duration::from_micros(p.got_sendme_usec_in),
439                &self.state,
440                &self.vegas.cwnd().expect("No CWND"),
441            );
442            assert!(ret.is_ok());
443
444            let signals = CongestionSignals::new(p.or_conn_blocked_in, 0);
445            let ret = self
446                .vegas
447                .sendme_received(&mut self.state, &mut self.rtt, signals);
448            assert!(ret.is_ok());
449
450            assert_eq!(self.rtt.ewma_rtt_usec().unwrap(), p.ewma_rtt_usec_out);
451            assert_eq!(self.rtt.min_rtt_usec().unwrap(), p.min_rtt_usec_out);
452            assert_eq!(self.vegas.cwnd().expect("No CWND").get(), p.cwnd_out);
453            assert_eq!(
454                self.vegas.cwnd().expect("No CWND").is_full(),
455                p.cwnd_full_out
456            );
457            assert_eq!(self.state.in_slow_start(), p.in_slow_start_out);
458            assert_eq!(self.vegas.is_blocked_on_chan(), p.blocked_chan_out);
459        }
460
461        fn run(&mut self) {
462            while let Some(param) = self.params.pop_front() {
463                self.run_once(&param);
464            }
465        }
466    }
467
468    pub(crate) fn build_vegas_params() -> VegasParams {
469        const OUTBUF_CELLS: u32 = 62;
470        VegasParamsBuilder::default()
471            .cell_in_queue_params(
472                (
473                    3 * OUTBUF_CELLS, // alpha
474                    4 * OUTBUF_CELLS, // beta
475                    5 * OUTBUF_CELLS, // delta
476                    3 * OUTBUF_CELLS, // gamma
477                    600,              // ss_cap
478                )
479                    .into(),
480            )
481            .ss_cwnd_max(5_000)
482            .cwnd_full_gap(4)
483            .cwnd_full_min_pct(Percentage::new(25))
484            .cwnd_full_per_cwnd(1)
485            .build()
486            .expect("Unable to build Vegas parameters")
487    }
488
489    #[test]
490    fn test_vectors() {
491        let vec1 = vec![
492            [100000, 200000, 0, 124, 100000, 100000, 155, 1, 0, 0],
493            [200000, 300000, 0, 155, 100000, 100000, 186, 1, 1, 0],
494            [350000, 500000, 0, 186, 133333, 100000, 217, 1, 1, 0],
495            [500000, 550000, 0, 217, 77777, 77777, 248, 1, 1, 0],
496            [600000, 700000, 0, 248, 92592, 77777, 279, 1, 1, 0],
497            [700000, 750000, 0, 279, 64197, 64197, 310, 1, 0, 0], // Fullness expiry
498            [750000, 875000, 0, 310, 104732, 64197, 341, 1, 1, 0],
499            [875000, 900000, 0, 341, 51577, 51577, 372, 1, 1, 0],
500            [900000, 950000, 0, 279, 50525, 50525, 403, 1, 1, 0],
501            [950000, 1000000, 0, 279, 50175, 50175, 434, 1, 1, 0],
502            [1000000, 1050000, 0, 279, 50058, 50058, 465, 1, 1, 0],
503            [1050000, 1100000, 0, 279, 50019, 50019, 496, 1, 1, 0],
504            [1100000, 1150000, 0, 279, 50006, 50006, 527, 1, 1, 0],
505            [1150000, 1200000, 0, 279, 50002, 50002, 558, 1, 1, 0],
506            [1200000, 1250000, 0, 550, 50000, 50000, 589, 1, 1, 0],
507            [1250000, 1300000, 0, 550, 50000, 50000, 620, 1, 0, 0], // Fullness expiry
508            [1300000, 1350000, 0, 550, 50000, 50000, 635, 1, 1, 0],
509            [1350000, 1400000, 0, 550, 50000, 50000, 650, 1, 1, 0],
510            [1400000, 1450000, 0, 150, 50000, 50000, 650, 1, 0, 0], // cwnd not full
511            [1450000, 1500000, 0, 150, 50000, 50000, 650, 1, 0, 0], // cwnd not full
512            [1500000, 1550000, 0, 550, 50000, 50000, 664, 1, 1, 0], // cwnd full
513            [1500000, 1600000, 0, 550, 83333, 50000, 584, 0, 1, 0], // gamma exit
514            [1600000, 1650000, 0, 550, 61111, 50000, 585, 0, 1, 0], // alpha
515            [1650000, 1700000, 0, 550, 53703, 50000, 586, 0, 1, 0],
516            [1700000, 1750000, 0, 100, 51234, 50000, 586, 0, 0, 0], // alpha, not full
517            [1750000, 1900000, 0, 100, 117078, 50000, 559, 0, 0, 0], // delta, not full
518            [1900000, 2000000, 0, 100, 105692, 50000, 558, 0, 0, 0], // beta, not full
519            [2000000, 2075000, 0, 500, 85230, 50000, 558, 0, 1, 0], // no change
520            [2075000, 2125000, 1, 500, 61743, 50000, 557, 0, 1, 1], // beta, blocked
521            [2125000, 2150000, 0, 500, 37247, 37247, 558, 0, 1, 0], // alpha
522            [2150000, 2350000, 0, 500, 145749, 37247, 451, 0, 1, 0], // delta
523        ];
524        VegasTest::new(vec1).run();
525
526        let vec2 = vec![
527            [100000, 200000, 0, 124, 100000, 100000, 155, 1, 0, 0],
528            [200000, 300000, 0, 155, 100000, 100000, 186, 1, 1, 0],
529            [350000, 500000, 0, 186, 133333, 100000, 217, 1, 1, 0],
530            [500000, 550000, 1, 217, 77777, 77777, 403, 0, 1, 1], // ss exit, blocked
531            [600000, 700000, 0, 248, 92592, 77777, 404, 0, 1, 0], // alpha
532            [700000, 750000, 1, 404, 64197, 64197, 403, 0, 0, 1], // blocked beta
533            [750000, 875000, 0, 403, 104732, 64197, 404, 0, 1, 0],
534        ];
535        VegasTest::new(vec2).run();
536
537        let vec3 = vec![
538            [18258527, 19002938, 0, 83, 744411, 744411, 155, 1, 0, 0],
539            [18258580, 19254257, 0, 52, 911921, 744411, 186, 1, 1, 0],
540            [20003224, 20645298, 0, 164, 732023, 732023, 217, 1, 1, 0],
541            [20003367, 21021444, 0, 133, 922725, 732023, 248, 1, 1, 0],
542            [20003845, 21265508, 0, 102, 1148683, 732023, 279, 1, 1, 0],
543            [20003975, 21429157, 0, 71, 1333015, 732023, 310, 1, 0, 0],
544            [20004309, 21707677, 0, 40, 1579917, 732023, 310, 1, 0, 0],
545        ];
546        VegasTest::new(vec3).run();
547
548        let vec4 = vec![
549            [358297091, 358854163, 0, 83, 557072, 557072, 155, 1, 0, 0],
550            [358297649, 359123845, 0, 52, 736488, 557072, 186, 1, 1, 0],
551            [359492879, 359995330, 0, 186, 580463, 557072, 217, 1, 1, 0],
552            [359493043, 360489243, 0, 217, 857621, 557072, 248, 1, 1, 0],
553            [359493232, 360489673, 0, 248, 950167, 557072, 279, 1, 1, 0],
554            [359493795, 360489971, 0, 279, 980839, 557072, 310, 1, 0, 0],
555            [359493918, 360490248, 0, 310, 991166, 557072, 341, 1, 1, 0],
556            [359494029, 360716465, 0, 341, 1145346, 557072, 372, 1, 1, 0],
557            [359996888, 360948867, 0, 372, 1016434, 557072, 403, 1, 1, 0],
558            [359996979, 360949330, 0, 403, 973712, 557072, 434, 1, 1, 0],
559            [360489528, 361113615, 0, 434, 740628, 557072, 465, 1, 1, 0],
560            [360489656, 361281604, 0, 465, 774841, 557072, 496, 1, 1, 0],
561            [360489837, 361500461, 0, 496, 932029, 557072, 482, 0, 1, 0],
562            [360489963, 361500631, 0, 482, 984455, 557072, 482, 0, 1, 0],
563            [360490117, 361842481, 0, 482, 1229727, 557072, 481, 0, 1, 0],
564        ];
565        VegasTest::new(vec4).run();
566    }
567}
tor_proto/congestion/vegas.rs

tor_proto/congestion/
vegas.rs
