gracefully recover from IncompleteProbeCycle
- Id
- 9de06f515be5098263df45743cdd3552b25f221a
- Author
- Caio
- Commit time
- 2022-10-24T11:26:18+02:00
Modified src/error.rs
/// steps didn't happen. Bug in the runtime/scheduling
/// mechanism most likely.
///
+ /// Foca tries to resume normal operations after emitting this
+ /// error, but any occurance of it is a sign that something is
+ /// not behaving as expected
+ ///
/// Must not happen under normal circumstances.
IncompleteProbeCycle,
Modified src/lib.rs
}
fn probe_random_member(&mut self, mut runtime: impl Runtime<T>) -> Result<()> {
+ debug_assert_eq!(self.connection_state, ConnectionState::Connected);
if !self.probe.validate() {
+ // Probe has invalid state. We'll reset and submit another timer
+ // so that foca can recover from the issue gracefully
+ self.probe.clear();
+ runtime.submit_after(
+ Timer::ProbeRandomMember(self.timer_token),
+ self.config.probe_period,
+ );
return Err(Error::IncompleteProbeCycle);
}
assert_eq!(
Ok(()),
other_foca.handle_data(&broadcast_message, &mut runtime)
+ );
+ }
+
+ #[test]
+ fn can_recover_from_incomplete_probe_cycle() {
+ // Here we get a foca in the middle of a probe cycle. The correct
+ // sequencing should submit `_send_indirect_probe`
+ let (mut foca, _probed, _send_indirect_probe) = craft_probing_foca(2);
+ let mut runtime = InMemoryRuntime::new();
+ // ... but we'll manually craft a ProbeRandomMember event instead
+ // to trigger the validation failure
+ assert_eq!(
+ Err(Error::IncompleteProbeCycle),
+ foca.handle_timer(Timer::ProbeRandomMember(foca.timer_token()), &mut runtime)
+ );
+
+ // This situation should lead to two things happening:
+ // 1. the probe state should become valid again
+ assert!(foca.probe().validate(), "didn't recover probe state");
+ // 2. should've scheduled a new probe
+ assert!(
+ runtime
+ .find_scheduling(|t| matches!(t, Timer::ProbeRandomMember(_)))
+ .is_some(),
+ "didn't submit a new probe event"
);
}
}