swarm/src/behaviour: Document impact of blocking code (#2482)

Co-authored-by: Max Inden <mail@max-inden.de>
This commit is contained in:
Frederik-Baetens
2022-02-09 20:26:59 +01:00
committed by GitHub
parent 44d63d8ed4
commit b39770b8e9

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@ -152,6 +152,13 @@ type THandlerInEvent<THandler> =
/// struct members are delegated to [`NetworkBehaviourEventProcess`] implementations. Those must be
/// provided by the user on the type that [`NetworkBehaviour`] is derived on.
///
/// Because these implementations are granted exclusive access to the [`NetworkBehaviour`],
/// [blocking code](https://ryhl.io/blog/async-what-is-blocking/) in these implementations will
/// block the entire [`Swarm`](crate::Swarm) from processing new events, since the swarm cannot progress
/// without also having exclusive access to the [`NetworkBehaviour`]. A better alternative is to execute
/// blocking or asynchronous logic on a separate task, perhaps with the help of a bounded channel to
/// maintain backpressure. The sender for the channel could be included in the NetworkBehaviours constructor.
///
/// Optionally one can provide a custom `poll` function through the `#[behaviour(poll_method =
/// "poll")]` attribute. This function must have the same signature as the [`NetworkBehaviour#poll`]
/// function and will be called last within the generated [`NetworkBehaviour`] implementation.