diff --git a/substrate/tendermint/machine/src/lib.rs b/substrate/tendermint/machine/src/lib.rs
index 3e388051..46386dc9 100644
--- a/substrate/tendermint/machine/src/lib.rs
+++ b/substrate/tendermint/machine/src/lib.rs
@@ -16,7 +16,10 @@ use futures::{
use tokio::time::sleep;
mod time;
-use time::{sys_time, CanonicalInstant};
+use time::*;
+
+mod round;
+use round::*;
mod message_log;
use message_log::MessageLog;
@@ -103,6 +106,21 @@ enum TendermintError<V: ValidatorId> {
Temporal,
}
+struct BlockData<N: Network> {
+ number: BlockNumber,
+ validator_id: Option<N::ValidatorId>,
+ proposal: N::Block,
+
+ log: MessageLog<N>,
+ slashes: HashSet<N::ValidatorId>,
+ end_time: HashMap<Round, CanonicalInstant>,
+
+ round: RoundData<N>,
+
+ locked: Option<(Round, <N::Block as Block>::Id)>,
+ valid: Option<(Round, N::Block)>,
+}
+
/// A machine executing the Tendermint protocol.
pub struct TendermintMachine<N: Network> {
network: N,
@@ -110,11 +128,6 @@ pub struct TendermintMachine<N: Network> {
validators: N::SignatureScheme,
weights: Arc<N::Weights>,
- validator_id: Option<N::ValidatorId>,
-
- number: BlockNumber,
- personal_proposal: N::Block,
-
queue:
VecDeque<Message<N::ValidatorId, N::Block, <N::SignatureScheme as SignatureScheme>::Signature>>,
msg_recv: mpsc::UnboundedReceiver<
@@ -122,17 +135,7 @@ pub struct TendermintMachine<N: Network> {
>,
step_recv: mpsc::UnboundedReceiver<(Commit<N::SignatureScheme>, N::Block)>,
- log: MessageLog<N>,
- slashes: HashSet<N::ValidatorId>,
- end_time: HashMap<Round, CanonicalInstant>,
- round: Round,
- start_time: CanonicalInstant,
- step: Step,
-
- locked: Option<(Round, <N::Block as Block>::Id)>,
- valid: Option<(Round, N::Block)>,
-
- timeouts: HashMap<Step, Instant>,
+ block: BlockData<N>,
}
pub type StepSender<N> =
@@ -158,126 +161,113 @@ pub struct TendermintHandle<N: Network> {
}
impl<N: Network + 'static> TendermintMachine<N> {
- fn timeout(&self, step: Step) -> CanonicalInstant {
- let adjusted_block = N::BLOCK_PROCESSING_TIME * (self.round.0 + 1);
- let adjusted_latency = N::LATENCY_TIME * (self.round.0 + 1);
- let offset = Duration::from_secs(
- (match step {
- Step::Propose => adjusted_block + adjusted_latency,
- Step::Prevote => adjusted_block + (2 * adjusted_latency),
- Step::Precommit => adjusted_block + (3 * adjusted_latency),
- })
- .into(),
- );
- self.start_time + offset
- }
-
fn broadcast(
&mut self,
data: Data<N::Block, <N::SignatureScheme as SignatureScheme>::Signature>,
) {
- if let Some(validator_id) = &self.validator_id {
+ if let Some(validator_id) = &self.block.validator_id {
// 27, 33, 41, 46, 60, 64
- self.step = data.step();
+ self.block.round.step = data.step();
self.queue.push_back(Message {
sender: *validator_id,
- number: self.number,
- round: self.round,
+ number: self.block.number,
+ round: self.block.round.round,
data,
});
}
}
- // 14-21
- fn round_propose(&mut self) -> bool {
- if Some(self.weights.proposer(self.number, self.round)) == self.validator_id {
- let (round, block) = self
- .valid
- .clone()
- .map(|(r, b)| (Some(r), b))
- .unwrap_or((None, self.personal_proposal.clone()));
+ fn populate_end_time(&mut self, round: Round) {
+ for r in (self.block.round.round.0 + 1) .. round.0 {
+ self.block.end_time.insert(
+ Round(r),
+ RoundData::<N>::new(Round(r), self.block.end_time[&Round(r - 1)]).end_time(),
+ );
+ }
+ }
+
+ // Start a new round. Returns true if we were the proposer
+ fn round(&mut self, round: Round, time: Option<CanonicalInstant>) -> bool {
+ // If skipping rounds, populate end_time
+ self.populate_end_time(round);
+
+ // 11-13
+ self.block.round =
+ RoundData::<N>::new(round, time.unwrap_or_else(|| self.block.end_time[&Round(round.0 - 1)]));
+ self.block.end_time.insert(round, self.block.round.end_time());
+
+ // 14-21
+ if Some(self.weights.proposer(self.block.number, self.block.round.round)) ==
+ self.block.validator_id
+ {
+ let (round, block) = if let Some((round, block)) = &self.block.valid {
+ (Some(*round), block.clone())
+ } else {
+ (None, self.block.proposal.clone())
+ };
self.broadcast(Data::Proposal(round, block));
true
} else {
- self.timeouts.insert(Step::Propose, self.timeout(Step::Propose).instant());
+ self.block.round.set_timeout(Step::Propose);
false
}
}
- fn round(&mut self, round: Round) -> bool {
- // If moving to a new round, correct the start time and populate end_time
- for r in self.round.0 .. round.0 {
- let end = self.timeout(Step::Precommit);
- self.end_time.insert(Round(r), end);
- self.round.0 += 1;
- self.start_time = end;
- }
-
- // Write the round regardless in case of reset
-
- // 11-13
- self.round = round;
- self.step = Step::Propose;
-
- // Write the end time
- self.end_time.insert(round, self.timeout(Step::Precommit));
- // Clear timeouts
- self.timeouts = HashMap::new();
-
- self.round_propose()
- }
-
// 53-54
async fn reset(&mut self, end_round: Round, proposal: N::Block) {
- // Wait for the next block interval
- let round_end = self.end_time[&end_round];
+ // Ensure we have the end time data for the last round
+ self.populate_end_time(end_round);
+
+ // Sleep until this round ends
+ let round_end = self.block.end_time[&end_round];
sleep(round_end.instant().saturating_duration_since(Instant::now())).await;
- self.validator_id = self.signer.validator_id().await;
+ // Only keep queued messages for this block
+ self.queue = self.queue.drain(..).filter(|msg| msg.number == self.block.number).collect();
- self.number.0 += 1;
- self.personal_proposal = proposal;
+ // Create the new block
+ self.block = BlockData {
+ number: BlockNumber(self.block.number.0 + 1),
+ validator_id: self.signer.validator_id().await,
+ proposal,
- self.queue = self.queue.drain(..).filter(|msg| msg.number == self.number).collect();
+ log: MessageLog::new(self.weights.clone()),
+ slashes: HashSet::new(),
+ end_time: HashMap::new(),
- self.log = MessageLog::new(self.weights.clone());
- self.slashes = HashSet::new();
- self.end_time = HashMap::new();
- self.start_time = round_end;
+ // This will be populated in the following round() call
+ round: RoundData::<N>::new(Round(0), CanonicalInstant::new(0)),
- self.locked = None;
- self.valid = None;
+ locked: None,
+ valid: None,
+ };
- self.round(Round(0));
+ // Start the first round
+ self.round(Round(0), Some(round_end));
}
async fn reset_by_commit(&mut self, commit: Commit<N::SignatureScheme>, proposal: N::Block) {
- let mut round = None;
- // If our start time is >= the commit's end time, it's from a previous round
- if self.start_time.canonical() >= commit.end_time {
- for (round_i, end_time) in &self.end_time {
- if end_time.canonical() == commit.end_time {
- round = Some(*round_i);
- break;
- }
- }
- } else {
- // Increment rounds until we find the round
- while {
- self.round(Round(self.round.0 + 1));
- // Use < to prevent an infinite loop
- self.end_time[&self.round].canonical() < commit.end_time
- } {}
- round =
- Some(self.round).filter(|_| self.end_time[&self.round].canonical() == commit.end_time);
+ let mut round = self.block.round.round;
+ // If this commit is for a round we don't have, jump up to it
+ while self.block.end_time[&round].canonical() < commit.end_time {
+ round.0 += 1;
+ self.populate_end_time(round);
}
+ // If this commit is for a prior round, find it
+ while self.block.end_time[&round].canonical() > commit.end_time {
+ if round.0 == 0 {
+ panic!("commit isn't for this machine's next block");
+ }
+ round.0 -= 1;
+ }
+ debug_assert_eq!(self.block.end_time[&round].canonical(), commit.end_time);
- self.reset(round.expect("commit wasn't for the machine's next block"), proposal).await;
+ self.reset(round, proposal).await;
}
async fn slash(&mut self, validator: N::ValidatorId) {
- if !self.slashes.contains(&validator) {
- self.slashes.insert(validator);
+ if !self.block.slashes.contains(&validator) {
+ self.block.slashes.insert(validator);
self.network.slash(validator).await;
}
}
@@ -312,61 +302,42 @@ impl<N: Network + 'static> TendermintMachine<N> {
validators,
weights: weights.clone(),
- validator_id,
-
- number: BlockNumber(last.0 .0 + 1),
- personal_proposal: proposal,
-
queue: VecDeque::new(),
msg_recv,
step_recv,
- log: MessageLog::new(weights),
- slashes: HashSet::new(),
- end_time: HashMap::new(),
- round: Round(0),
- // The end time of the last block is the start time for this one
- // The Commit explicitly contains the end time, so loading the last commit will provide
- // this. The only exception is for the genesis block, which doesn't have a commit
- // Using the genesis time in place will cause this block to be created immediately
- // after it, without the standard amount of separation (so their times will be
- // equivalent or minimally offset)
- // For callers wishing to avoid this, they should pass (0, GENESIS + N::block_time())
- start_time: CanonicalInstant::new(last.1),
- step: Step::Propose,
+ block: BlockData {
+ number: BlockNumber(last.0 .0 + 1),
+ validator_id,
+ proposal,
- locked: None,
- valid: None,
+ log: MessageLog::new(weights),
+ slashes: HashSet::new(),
+ end_time: HashMap::new(),
- timeouts: HashMap::new(),
+ // This will be populated in the following round() call
+ round: RoundData::<N>::new(Round(0), CanonicalInstant::new(0)),
+
+ locked: None,
+ valid: None,
+ },
};
- machine.round(Round(0));
+
+ // The end time of the last block is the start time for this one
+ // The Commit explicitly contains the end time, so loading the last commit will provide
+ // this. The only exception is for the genesis block, which doesn't have a commit
+ // Using the genesis time in place will cause this block to be created immediately
+ // after it, without the standard amount of separation (so their times will be
+ // equivalent or minimally offset)
+ // For callers wishing to avoid this, they should pass (0, GENESIS + N::block_time())
+ machine.round(Round(0), Some(CanonicalInstant::new(last.1)));
machine
},
}
}
pub async fn run(mut self) {
- self.round(Round(0));
-
loop {
- // Create futures for the various timeouts
- let timeout_future = |step| {
- let timeout = self.timeouts.get(&step).copied();
- (async move {
- if let Some(timeout) = timeout {
- sleep(timeout.saturating_duration_since(Instant::now())).await;
- } else {
- future::pending::<()>().await;
- }
- })
- .fuse()
- };
- let propose_timeout = timeout_future(Step::Propose);
- let prevote_timeout = timeout_future(Step::Prevote);
- let precommit_timeout = timeout_future(Step::Precommit);
- futures::pin_mut!(propose_timeout, prevote_timeout, precommit_timeout);
-
// Also create a future for if the queue has a message
// Does not pop_front as if another message has higher priority, its future will be handled
// instead in this loop, and the popped value would be dropped with the next iteration
@@ -391,31 +362,28 @@ impl<N: Network + 'static> TendermintMachine<N> {
},
// Handle any timeouts
- _ = &mut propose_timeout => {
+ step = self.block.round.timeout_future().fuse() => {
// Remove the timeout so it doesn't persist, always being the selected future due to bias
- // While this does enable the below get_entry calls to enter timeouts again, they'll
- // never attempt to add a timeout after this timeout has expired
- self.timeouts.remove(&Step::Propose);
- if self.step == Step::Propose {
- // Slash the validator for not proposing when they should've
- self.slash(self.weights.proposer(self.number, self.round)).await;
- self.broadcast(Data::Prevote(None));
+ // While this does enable the timeout to be entered again, the timeout setting code will
+ // never attempt to add a timeout after its timeout has expired
+ self.block.round.timeouts.remove(&step);
+ // Only run if it's still the step in question
+ if self.block.round.step == step {
+ match step {
+ Step::Propose => {
+ // Slash the validator for not proposing when they should've
+ self.slash(self.weights.proposer(self.block.number, self.block.round.round)).await;
+ self.broadcast(Data::Prevote(None));
+ },
+ Step::Prevote => self.broadcast(Data::Precommit(None)),
+ Step::Precommit => {
+ self.round(Round(self.block.round.round.0 + 1), None);
+ continue;
+ }
+ }
}
None
},
- _ = &mut prevote_timeout => {
- self.timeouts.remove(&Step::Prevote);
- if self.step == Step::Prevote {
- self.broadcast(Data::Precommit(None));
- }
- None
- },
- _ = &mut precommit_timeout => {
- // Technically unnecessary since round() will clear the timeouts
- self.timeouts.remove(&Step::Precommit);
- self.round(Round(self.round.0.wrapping_add(1)));
- continue;
- },
// Handle any received messages
msg = self.msg_recv.next() => {
@@ -440,6 +408,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
let mut validators = vec![];
let mut sigs = vec![];
for (v, sig) in self
+ .block
.log
.precommitted
.iter()
@@ -450,7 +419,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
}
let commit = Commit {
- end_time: self.end_time[&msg.round].canonical(),
+ end_time: self.block.end_time[&msg.round].canonical(),
validators,
signature: N::SignatureScheme::aggregate(&sigs),
};
@@ -484,7 +453,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
// Only perform this verification if we already have the end_time
// Else, there's a DoS where we receive a precommit for some round infinitely in the future
// which forces to calculate every end time
- if let Some(end_time) = self.end_time.get(&round) {
+ if let Some(end_time) = self.block.end_time.get(&round) {
if !self.validators.verify(sender, &commit_msg(end_time.canonical(), id.as_ref()), sig) {
Err(TendermintError::Malicious(sender))?;
}
@@ -497,7 +466,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
&mut self,
msg: Message<N::ValidatorId, N::Block, <N::SignatureScheme as SignatureScheme>::Signature>,
) -> Result<Option<N::Block>, TendermintError<N::ValidatorId>> {
- if msg.number != self.number {
+ if msg.number != self.block.number {
Err(TendermintError::Temporal)?;
}
@@ -511,7 +480,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
Err(TendermintError::Malicious(msg.sender))?;
};
- if !self.log.log(msg.clone())? {
+ if !self.block.log.log(msg.clone())? {
return Ok(None);
}
@@ -520,13 +489,14 @@ impl<N: Network + 'static> TendermintMachine<N> {
// Run the finalizer to see if it applies
// 49-52
if matches!(msg.data, Data::Proposal(..)) || matches!(msg.data, Data::Precommit(_)) {
- let proposer = self.weights.proposer(self.number, msg.round);
+ let proposer = self.weights.proposer(self.block.number, msg.round);
// Get the proposal
- if let Some(Data::Proposal(_, block)) = self.log.get(msg.round, proposer, Step::Propose) {
+ if let Some(Data::Proposal(_, block)) = self.block.log.get(msg.round, proposer, Step::Propose)
+ {
// Check if it has gotten a sufficient amount of precommits
// Use a junk signature since message equality disregards the signature
- if self.log.has_consensus(
+ if self.block.log.has_consensus(
msg.round,
Data::Precommit(Some((block.id(), self.signer.sign(&[]).await))),
) {
@@ -537,15 +507,15 @@ impl<N: Network + 'static> TendermintMachine<N> {
// Else, check if we need to jump ahead
#[allow(clippy::comparison_chain)]
- if msg.round.0 < self.round.0 {
+ if msg.round.0 < self.block.round.round.0 {
// Prior round, disregard if not finalizing
return Ok(None);
- } else if msg.round.0 > self.round.0 {
+ } else if msg.round.0 > self.block.round.round.0 {
// 55-56
// Jump, enabling processing by the below code
- if self.log.round_participation(msg.round) > self.weights.fault_thresold() {
+ if self.block.log.round_participation(msg.round) > self.weights.fault_thresold() {
// If this round already has precommit messages, verify their signatures
- let round_msgs = self.log.log[&msg.round].clone();
+ let round_msgs = self.block.log.log[&msg.round].clone();
for (validator, msgs) in &round_msgs {
if let Some(data) = msgs.get(&Step::Precommit) {
if self.verify_precommit_signature(*validator, msg.round, data).is_err() {
@@ -555,7 +525,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
}
// If we're the proposer, return now so we re-run processing with our proposal
// If we continue now, it'd just be wasted ops
- if self.round(msg.round) {
+ if self.round(msg.round, None) {
return Ok(None);
}
} else {
@@ -567,12 +537,12 @@ impl<N: Network + 'static> TendermintMachine<N> {
// The paper executes these checks when the step is prevote. Making sure this message warrants
// rerunning these checks is a sane optimization since message instances is a full iteration
// of the round map
- if (self.step == Step::Prevote) && matches!(msg.data, Data::Prevote(_)) {
- let (participation, weight) = self.log.message_instances(self.round, Data::Prevote(None));
+ if (self.block.round.step == Step::Prevote) && matches!(msg.data, Data::Prevote(_)) {
+ let (participation, weight) =
+ self.block.log.message_instances(self.block.round.round, Data::Prevote(None));
// 34-35
if participation >= self.weights.threshold() {
- let timeout = self.timeout(Step::Prevote);
- self.timeouts.entry(Step::Prevote).or_insert_with(|| timeout.instant());
+ self.block.round.set_timeout(Step::Prevote);
}
// 44-46
@@ -584,16 +554,17 @@ impl<N: Network + 'static> TendermintMachine<N> {
// 47-48
if matches!(msg.data, Data::Precommit(_)) &&
- self.log.has_participation(self.round, Step::Precommit)
+ self.block.log.has_participation(self.block.round.round, Step::Precommit)
{
- let timeout = self.timeout(Step::Precommit);
- self.timeouts.entry(Step::Precommit).or_insert_with(|| timeout.instant());
+ self.block.round.set_timeout(Step::Precommit);
}
- let proposer = self.weights.proposer(self.number, self.round);
- if let Some(Data::Proposal(vr, block)) = self.log.get(self.round, proposer, Step::Propose) {
+ let proposer = self.weights.proposer(self.block.number, self.block.round.round);
+ if let Some(Data::Proposal(vr, block)) =
+ self.block.log.get(self.block.round.round, proposer, Step::Propose)
+ {
// 22-33
- if self.step == Step::Propose {
+ if self.block.round.step == Step::Propose {
// Delay error handling (triggering a slash) until after we vote.
let (valid, err) = match self.network.validate(block).await {
Ok(_) => (true, Ok(None)),
@@ -607,19 +578,19 @@ impl<N: Network + 'static> TendermintMachine<N> {
// 23 and 29. If it's some, both are satisfied if they're for the same ID. If it's some
// with different IDs, the function on 22 rejects yet the function on 28 has one other
// condition
- let locked = self.locked.as_ref().map(|(_, id)| id == &block.id()).unwrap_or(true);
+ let locked = self.block.locked.as_ref().map(|(_, id)| id == &block.id()).unwrap_or(true);
let mut vote = raw_vote.filter(|_| locked);
if let Some(vr) = vr {
// Malformed message
- if vr.0 >= self.round.0 {
+ if vr.0 >= self.block.round.round.0 {
Err(TendermintError::Malicious(msg.sender))?;
}
- if self.log.has_consensus(*vr, Data::Prevote(Some(block.id()))) {
+ if self.block.log.has_consensus(*vr, Data::Prevote(Some(block.id()))) {
// Allow differing locked values if the proposal has a newer valid round
// This is the other condition described above
- if let Some((locked_round, _)) = self.locked.as_ref() {
+ if let Some((locked_round, _)) = self.block.locked.as_ref() {
vote = vote.or_else(|| raw_vote.filter(|_| locked_round.0 <= vr.0));
}
@@ -630,27 +601,36 @@ impl<N: Network + 'static> TendermintMachine<N> {
self.broadcast(Data::Prevote(vote));
return err;
}
- } else if self.valid.as_ref().map(|(round, _)| round != &self.round).unwrap_or(true) {
+ } else if self
+ .block
+ .valid
+ .as_ref()
+ .map(|(round, _)| round != &self.block.round.round)
+ .unwrap_or(true)
+ {
// 36-43
// The run once condition is implemented above. Sinve valid will always be set, it not
// being set, or only being set historically, means this has yet to be run
- if self.log.has_consensus(self.round, Data::Prevote(Some(block.id()))) {
+ if self.block.log.has_consensus(self.block.round.round, Data::Prevote(Some(block.id()))) {
match self.network.validate(block).await {
Ok(_) => (),
Err(BlockError::Temporal) => (),
Err(BlockError::Fatal) => Err(TendermintError::Malicious(proposer))?,
};
- self.valid = Some((self.round, block.clone()));
- if self.step == Step::Prevote {
- self.locked = Some((self.round, block.id()));
+ self.block.valid = Some((self.block.round.round, block.clone()));
+ if self.block.round.step == Step::Prevote {
+ self.block.locked = Some((self.block.round.round, block.id()));
self.broadcast(Data::Precommit(Some((
block.id(),
self
.signer
- .sign(&commit_msg(self.end_time[&self.round].canonical(), block.id().as_ref()))
+ .sign(&commit_msg(
+ self.block.end_time[&self.block.round.round].canonical(),
+ block.id().as_ref(),
+ ))
.await,
))));
return Ok(None);
diff --git a/substrate/tendermint/machine/src/round.rs b/substrate/tendermint/machine/src/round.rs
new file mode 100644
index 00000000..2763e5f7
--- /dev/null
+++ b/substrate/tendermint/machine/src/round.rs
@@ -0,0 +1,82 @@
+use std::{
+ marker::PhantomData,
+ time::{Duration, Instant},
+ collections::HashMap,
+};
+
+use futures::{FutureExt, future};
+use tokio::time::sleep;
+
+use crate::{
+ time::CanonicalInstant,
+ Step,
+ ext::{Round, Network},
+};
+
+pub(crate) struct RoundData<N: Network> {
+ _network: PhantomData<N>,
+ pub(crate) round: Round,
+ pub(crate) start_time: CanonicalInstant,
+ pub(crate) step: Step,
+ pub(crate) timeouts: HashMap<Step, Instant>,
+}
+
+impl<N: Network> RoundData<N> {
+ pub(crate) fn new(round: Round, start_time: CanonicalInstant) -> Self {
+ RoundData {
+ _network: PhantomData,
+ round,
+ start_time,
+ step: Step::Propose,
+ timeouts: HashMap::new(),
+ }
+ }
+
+ fn timeout(&self, step: Step) -> CanonicalInstant {
+ let adjusted_block = N::BLOCK_PROCESSING_TIME * (self.round.0 + 1);
+ let adjusted_latency = N::LATENCY_TIME * (self.round.0 + 1);
+ let offset = Duration::from_secs(
+ (match step {
+ Step::Propose => adjusted_block + adjusted_latency,
+ Step::Prevote => adjusted_block + (2 * adjusted_latency),
+ Step::Precommit => adjusted_block + (3 * adjusted_latency),
+ })
+ .into(),
+ );
+ self.start_time + offset
+ }
+
+ pub(crate) fn end_time(&self) -> CanonicalInstant {
+ self.timeout(Step::Precommit)
+ }
+
+ pub(crate) fn set_timeout(&mut self, step: Step) {
+ let timeout = self.timeout(step).instant();
+ self.timeouts.entry(step).or_insert(timeout);
+ }
+
+ pub(crate) async fn timeout_future(&self) -> Step {
+ let timeout_future = |step| {
+ let timeout = self.timeouts.get(&step).copied();
+ (async move {
+ if let Some(timeout) = timeout {
+ sleep(timeout.saturating_duration_since(Instant::now())).await;
+ } else {
+ future::pending::<()>().await;
+ }
+ step
+ })
+ .fuse()
+ };
+ let propose_timeout = timeout_future(Step::Propose);
+ let prevote_timeout = timeout_future(Step::Prevote);
+ let precommit_timeout = timeout_future(Step::Precommit);
+ futures::pin_mut!(propose_timeout, prevote_timeout, precommit_timeout);
+
+ futures::select_biased! {
+ step = propose_timeout => step,
+ step = prevote_timeout => step,
+ step = precommit_timeout => step,
+ }
+ }
+}