Struct lightning_background_processor::BackgroundProcessor

pub struct BackgroundProcessor {
    pub thread_handle: JoinHandle<Result<(), Error>>,
    // some fields omitted
}

BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep Rust-Lightning running properly, and (2) either can or should be run in the background. Its responsibilities are:

• Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so, writing it to disk/backups by invoking the callback given to it at startup. ChannelManager persistence should be done in the background.
• Calling ChannelManager::timer_chan_freshness_every_min() every minute (can be done in the background).

Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date, then there is a risk of channels force-closing on startup when the manager realizes it’s outdated. However, as long as ChannelMonitor backups are sound, no funds besides those used for unilateral chain closure fees are at risk.

Fields

thread_handle: JoinHandle<Result<(), Error>>

May be used to retrieve and handle the error if BackgroundProcessor’s thread exits due to an error while persisting.

Implementations

impl BackgroundProcessor

pub fn start<PM, Signer, M, T, K, F, L>(
    persist_manager: PM,
    manager: Arc<ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>>,
    logger: Arc<L>
) -> Self where
    Signer: 'static + Sign,
    M: 'static + Watch<Signer>,
    T: 'static + BroadcasterInterface,
    K: 'static + KeysInterface<Signer = Signer>,
    F: 'static + FeeEstimator,
    L: 'static + Logger,
    PM: 'static + Send + Fn(&ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>) -> Result<(), Error>, 

Start a background thread that takes care of responsibilities enumerated in the top-level documentation.

If persist_manager returns an error, then this thread will return said error (and start() will need to be called again to restart the BackgroundProcessor). Users should wait on thread_handle’s join() method to be able to tell if and when an error is returned, or implement persist_manager such that an error is never returned to the BackgroundProcessor

persist_manager is responsible for writing out the ChannelManager to disk, and/or uploading to one or more backup services. See ChannelManager::write for writing out a ChannelManager. See FilesystemPersister::persist_manager for Rust-Lightning’s provided implementation.

pub fn stop(self) -> Result<(), Error>

Stop BackgroundProcessor’s thread.