node/reactor: Correctly handle error events

`fn handle_events` would panic, if there were multiple events for one
token, and the first one that happened to be handled was an error.
Indeed it is concerning if a token is encountered that was never
registered before. However, tokens that were just deregistered must be
tracked.

Using `Vec` here seems a bit costly, in the future,
`smallvec::SmallVec` could be considered.

The "unregister" methods are renamed to "deregister" to better line up
with `mio` vocabulary.

Log statements that helped analysis of the panic that occurred here
are overhauled and improved, requiring a `Debug` bound on types that
obviously implement it.
This commit is contained in:
Lorenz Leutgeb 2025-10-13 17:42:37 +02:00 committed by Fintan Halpenny
parent 72cf3d1919
commit 0b3424857e
5 changed files with 57 additions and 40 deletions

View File

@ -203,13 +203,13 @@ pub trait ReactionHandler: Send + Iterator<Item = Action<Self::Listener, Self::T
/// Listener resources are resources which may spawn more resources and can't be written to. A /// Listener resources are resources which may spawn more resources and can't be written to. A
/// typical example of a listener resource is a [`std::net::TcpListener`], however this may also /// typical example of a listener resource is a [`std::net::TcpListener`], however this may also
/// be a special form of a peripheral device or something else. /// be a special form of a peripheral device or something else.
type Listener: EventHandler + Source + Send; type Listener: EventHandler + Source + Send + Debug;
/// Type for a transport resource. /// Type for a transport resource.
/// ///
/// Transport is a "full" resource which can be read from - and written to. Usual files, network /// Transport is a "full" resource which can be read from - and written to. Usual files, network
/// connections, database connections etc are all fall into this category. /// connections, database connections etc are all fall into this category.
type Transport: EventHandler + Source + Send + WriteAtomic; type Transport: EventHandler + Source + Send + Debug + WriteAtomic;
/// Method called by the reactor on the start of each event loop once the poll has returned. /// Method called by the reactor on the start of each event loop once the poll has returned.
fn tick(&mut self, time: localtime::LocalTime); fn tick(&mut self, time: localtime::LocalTime);
@ -428,50 +428,60 @@ impl<H: ReactionHandler> Runtime<H> {
/// ///
/// Whether one of the events was originated from the waker. /// Whether one of the events was originated from the waker.
fn handle_events(&mut self, time: LocalTime, events: Events) -> bool { fn handle_events(&mut self, time: LocalTime, events: Events) -> bool {
log::trace!(target: "reactor", "Handling events");
let mut awoken = false; let mut awoken = false;
let mut deregistered = Vec::new();
for event in events.into_iter() { for event in events.into_iter() {
let id = event.token(); let token = event.token();
if id == WAKER { if token == WAKER {
log::trace!(target: "reactor", "Awoken by the controller"); log::trace!(target: "reactor", "Awoken by the controller");
awoken = true; awoken = true;
} else if self.listeners.contains_key(&id) { } else if self.listeners.contains_key(&token) {
log::trace!(target: "reactor", event:debug; "From listener"); log::trace!(target: "reactor", token=token.0; "Event from listener with token {}: {:?}", token.0, event);
if !event.is_error() { if !event.is_error() {
let listener = self.listeners.get_mut(&id).expect("resource disappeared"); let listener = self
.listeners
.get_mut(&token)
.expect("resource disappeared");
listener listener
.handle(event) .handle(event)
.into_iter() .into_iter()
.for_each(|service_event| { .for_each(|service_event| {
self.service.listener_reacted(id, service_event, time); self.service.listener_reacted(token, service_event, time);
}); });
} else { } else {
let listener = self let listener = self.deregister_listener(token).unwrap_or_else(|| {
.unregister_listener(id) panic!("listener with token {} has disappeared", token.0)
.expect("listener has disappeared"); });
self.service self.service
.handle_error(Error::ListenerDisconnect(id, listener)); .handle_error(Error::ListenerDisconnect(token, listener));
deregistered.push(token);
} }
} else if self.transports.contains_key(&id) { } else if self.transports.contains_key(&token) {
log::trace!(target: "reactor", event:debug; "From transport"); log::trace!(target: "reactor", token=token.0; "Event from transport with token {}: {:?}", token.0, event);
if !event.is_error() { if !event.is_error() {
let transport = self.transports.get_mut(&id).expect("resource disappeared"); let transport = self
.transports
.get_mut(&token)
.expect("resource disappeared");
transport transport
.handle(event) .handle(event)
.into_iter() .into_iter()
.for_each(|service_event| { .for_each(|service_event| {
self.service.transport_reacted(id, service_event, time); self.service.transport_reacted(token, service_event, time);
}); });
} else { } else {
let transport = self let transport = self.deregister_transport(token).unwrap_or_else(|| {
.unregister_transport(id) panic!("transport with token {} has disappeared", token.0)
.expect("transport has disappeared"); });
self.service self.service
.handle_error(Error::TransportDisconnect(id, transport)); .handle_error(Error::TransportDisconnect(token, transport));
deregistered.push(token);
} }
} else { } else if !deregistered.contains(&token) {
panic!("token in poll which is not a known waker, listener or transport") log::warn!(target: "reactor", token=token.0; "Event from unknown token {}: {:?}", token.0, event);
} }
} }
@ -498,7 +508,7 @@ impl<H: ReactionHandler> Runtime<H> {
) -> Result<(), Error<H::Listener, H::Transport>> { ) -> Result<(), Error<H::Listener, H::Transport>> {
match action { match action {
Action::RegisterListener(token, mut listener) => { Action::RegisterListener(token, mut listener) => {
log::debug!(target: "reactor", token=token.0; "Registering listener"); log::trace!(target: "reactor", token=token.0; "Registering listener {:?} with token {}", listener, token.0);
self.poll self.poll
.registry() .registry()
@ -520,33 +530,33 @@ impl<H: ReactionHandler> Runtime<H> {
.transport_registered(token, &self.transports[&token]); .transport_registered(token, &self.transports[&token]);
} }
Action::UnregisterListener(token) => { Action::UnregisterListener(token) => {
let Some(listener) = self.unregister_listener(token) else { let Some(listener) = self.deregister_listener(token) else {
return Ok(()); return Ok(());
}; };
log::debug!(target: "reactor", token=token.0; "Handing over listener"); log::debug!(target: "reactor", token=token.0; "Handing over listener {listener:?} with token {}", token.0);
self.service.handover_listener(token, listener); self.service.handover_listener(token, listener);
} }
Action::UnregisterTransport(token) => { Action::UnregisterTransport(token) => {
let Some(transport) = self.unregister_transport(token) else { let Some(transport) = self.deregister_transport(token) else {
return Ok(()); return Ok(());
}; };
log::debug!(target: "reactor", token=token.0; "Handing over transport"); log::debug!(target: "reactor", token=token.0; "Handing over transport {transport:?} with token {}", token.0);
self.service.handover_transport(token, transport); self.service.handover_transport(token, transport);
} }
Action::Send(token, data) => { Action::Send(token, data) => {
log::trace!(target: "reactor", "Sending {} bytes to {token:?}", data.len()); log::trace!(target: "reactor", token=token.0; "Sending {} bytes to {token:?}", data.len());
if let Some(transport) = self.transports.get_mut(&token) { if let Some(transport) = self.transports.get_mut(&token) {
if let Err(e) = transport.write_atomic(&data) { if let Err(e) = transport.write_atomic(&data) {
log::error!(target: "reactor", "Fatal error writing to transport {token:?}, disconnecting. Error details: {e:?}"); log::error!(target: "reactor", "Fatal error writing to transport {token:?}, disconnecting. Error details: {e:?}");
if let Some(transport) = self.unregister_transport(token) { if let Some(transport) = self.deregister_transport(token) {
return Err(Error::TransportDisconnect(token, transport)); return Err(Error::TransportDisconnect(token, transport));
} }
} }
} else { } else {
log::error!(target: "reactor", "Transport {token:?} is not in the reactor"); log::error!(target: "reactor", token=token.0; "No transport with token {token:?} is known!");
} }
} }
Action::SetTimer(duration) => { Action::SetTimer(duration) => {
@ -562,27 +572,27 @@ impl<H: ReactionHandler> Runtime<H> {
log::info!(target: "reactor", "Shutdown"); log::info!(target: "reactor", "Shutdown");
} }
fn unregister_listener(&mut self, token: Token) -> Option<H::Listener> { fn deregister_listener(&mut self, token: Token) -> Option<H::Listener> {
let Some(mut source) = self.listeners.remove(&token) else { let Some(mut source) = self.listeners.remove(&token) else {
log::warn!(target: "reactor", token=token.0; "Unregistering non-registered listener"); log::warn!(target: "reactor", token=token.0; "Deregistering non-registered listener with token {}", token.0);
return None; return None;
}; };
if let Err(err) = self.poll.registry().deregister(&mut source) { if let Err(err) = self.poll.registry().deregister(&mut source) {
log::warn!(target: "reactor", token=token.0; "Failed to deregister listener from mio: {err}"); log::warn!(target: "reactor", token=token.0; "Failed to deregister listener with token {} from mio: {err}", token.0);
} }
Some(source) Some(source)
} }
fn unregister_transport(&mut self, token: Token) -> Option<H::Transport> { fn deregister_transport(&mut self, token: Token) -> Option<H::Transport> {
let Some(mut source) = self.transports.remove(&token) else { let Some(mut source) = self.transports.remove(&token) else {
log::warn!(target: "reactor", token=token.0; "Unregistering non-registered transport"); log::warn!(target: "reactor", token=token.0; "Deregistering non-registered transport with token {}", token.0);
return None; return None;
}; };
if let Err(err) = self.poll.registry().deregister(&mut source) { if let Err(err) = self.poll.registry().deregister(&mut source) {
log::warn!(target: "reactor", token=token.0; "Failed to deregister transport from mio: {err}"); log::warn!(target: "reactor", token=token.0; "Failed to deregister transport with token {} from mio: {err}", token.0);
} }
Some(source) Some(source)

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@ -100,7 +100,7 @@ impl<M: StateMachine, S: Session> Display for ProtocolArtifact<M, S> {
} }
} }
#[derive(Copy, Clone, Eq, PartialEq)] #[derive(Copy, Clone, Eq, PartialEq, Debug)]
pub struct Protocol<M: StateMachine, S: Session> { pub struct Protocol<M: StateMachine, S: Session> {
pub(crate) state: M, pub(crate) state: M,
pub(crate) session: S, pub(crate) session: S,

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@ -1,6 +1,7 @@
pub mod handle; pub mod handle;
pub mod thread; pub mod thread;
use std::fmt::Debug;
use std::path::PathBuf; use std::path::PathBuf;
use std::{fs, io, net}; use std::{fs, io, net};
@ -131,7 +132,11 @@ impl Runtime {
signer: Device<G>, signer: Device<G>,
) -> Result<Runtime, Error> ) -> Result<Runtime, Error>
where where
G: crypto::signature::Signer<crypto::Signature> + Ecdh<Pk = NodeId> + Clone + 'static, G: crypto::signature::Signer<crypto::Signature>
+ Ecdh<Pk = NodeId>
+ Clone
+ Debug
+ 'static,
{ {
let id = *signer.public_key(); let id = *signer.public_key();
let alias = config.alias.clone(); let alias = config.alias.clone();

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@ -1,3 +1,4 @@
use std::fmt::Debug;
use std::io::BufRead as _; use std::io::BufRead as _;
use std::mem::ManuallyDrop; use std::mem::ManuallyDrop;
use std::path::Path; use std::path::Path;
@ -455,7 +456,7 @@ impl Node<MockSigner> {
} }
} }
impl<G: cyphernet::Ecdh<Pk = NodeId> + Signer<Signature> + Clone> Node<G> { impl<G: cyphernet::Ecdh<Pk = NodeId> + Signer<Signature> + Clone + Debug> Node<G> {
/// Spawn a node in its own thread. /// Spawn a node in its own thread.
pub fn spawn(self) -> NodeHandle<G> { pub fn spawn(self) -> NodeHandle<G> {
let alias = self.config.alias.clone(); let alias = self.config.alias.clone();

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@ -3,6 +3,7 @@
//! We use the Noise XK handshake pattern to establish an encrypted stream with a remote peer. //! We use the Noise XK handshake pattern to establish an encrypted stream with a remote peer.
use std::collections::hash_map::Entry; use std::collections::hash_map::Entry;
use std::collections::VecDeque; use std::collections::VecDeque;
use std::fmt::Debug;
use std::sync::Arc; use std::sync::Arc;
use std::{io, net, time}; use std::{io, net, time};
@ -490,7 +491,7 @@ impl<D, S, G> reactor::ReactionHandler for Wire<D, S, G>
where where
D: service::Store + Send, D: service::Store + Send,
S: WriteStorage + Send + 'static, S: WriteStorage + Send + 'static,
G: crypto::signature::Signer<crypto::Signature> + Ecdh<Pk = NodeId> + Clone + Send, G: crypto::signature::Signer<crypto::Signature> + Ecdh<Pk = NodeId> + Clone + Send + Debug,
{ {
type Listener = Listener; type Listener = Listener;
type Transport = Transport<WireSession<G>>; type Transport = Transport<WireSession<G>>;