Struct FloodingConsensus 

pub struct FloodingConsensus<P: Clone + Ord, L: VolatileLink<Flood<P>> = PerfectLink<Flood<P>>> { /* private fields */ }

Regular consensus in the fail-stop model, over best-effort broadcast and a failure detector.

L is the link under the broadcast, and is a parameter rather than a fixed type: what this stack needs is a link speaking pl::Cmd and pl::Ind, not one particular implementation. An application with its own driver-backed link runs this consensus over it unedited. It defaults to PerfectLink, so the ordinary stack is still written FloodingConsensus<P>.

Implementations

impl<P: Clone + Ord, L: VolatileLink<Flood<P>>> FloodingConsensus<P, L>

pub fn with_link( me: NodeId, members: impl IntoIterator<Item = NodeId>, link: L, heartbeat: Duration, detect_after: Duration, ) -> Self

Consensus among members, over a link the caller supplies.

The link is anything satisfying crate::link::Link; this layer never names an implementation.

impl<P: Clone + Ord> FloodingConsensus<P, PerfectLink<Flood<P>>>

pub fn new( me: NodeId, members: impl IntoIterator<Item = NodeId>, retransmit: Duration, heartbeat: Duration, detect_after: Duration, ) -> Self

Consensus among members, which must include me.

detect_after must exceed heartbeat plus the network’s delivery bound, or the detector will accuse correct processes and agreement can break — which is the whole subject of this module’s documentation.

pub fn correct(&self) -> impl Iterator<Item = NodeId> + '_

The processes still believed correct, in a stable order.

pub fn round(&self) -> u64

The round this process is currently in.

pub fn decision(&self) -> Option<&P>

What this process decided, if it has.

pub fn heard_from(&self, round: u64) -> impl Iterator<Item = NodeId> + '_

Who this process heard from in round, for tests watching the guard form.

pub fn rounds_recorded(&self) -> usize

How many rounds hold state. Bounded by the membership; see the space note above.

pub fn state_entries(&self) -> usize

Every entry held across every round — the measure a bounded-space test asserts on.

Trait Implementations

impl<P: Debug + Clone + Ord, L: Debug + VolatileLink<Flood<P>>> Debug for FloodingConsensus<P, L>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<P: Clone + Ord, L: VolatileLink<Flood<P>>> Protocol for FloodingConsensus<P, L>

type Scope = Infallible

No session beneath, so no scope end can be constructed — as for both children.

type Meta = Infallible

Keeps nothing durably: a crash loses everything this protocol knows.

fn on_init(&mut self, cx: &mut ProtoCx<'_, Self>)

Failure detection begins here, as Module 2.6 has it. It used to need a Start command because there was no init event to hang the detector’s first timer on.

type Cmd = Cmd<P>

Requests from the layer above.

type Ind = Ind<P>

Indications to the layer above — this protocol delivering on its guarantee.

type Msg = Wire<<L as Protocol>::Msg>

What crosses the wire to a peer running the same protocol.

type Note = Note

The vocabulary in which this protocol narrates its decisions.

type Entry = Infallible

The durable entries this protocol appends: what accumulates.

fn on_cmd(&mut self, cmd: Cmd<P>, cx: &mut ProtoCx<'_, Self>)

Handle a request from the layer above.

fn on_msg(&mut self, from: NodeId, msg: Self::Msg, cx: &mut ProtoCx<'_, Self>)

Handle a message received from from.

fn on_timer(&mut self, id: TimerId, cx: &mut ProtoCx<'_, Self>)

Handle a timer that fired somewhere in this protocol or in what it composes.

fn on_recovery( &mut self, _cx: &mut Cx<'_, Self::Msg, Self::Ind, Self::Note, Self::Meta, Self::Entry>, )

Resume after a crash, reading what survived.

fn on_scope_event( &mut self, _scope: Self::Scope, _cx: &mut Cx<'_, Self::Msg, Self::Ind, Self::Note, Self::Meta, Self::Entry>, )

Handle a boundary of a scope this protocol’s guarantees depend on — its end, or the beginning of the one that succeeds it.