From: Matt Corallo <git@bluematt.me>
Date: Sun, 1 Aug 2021 02:42:42 +0000 (+0000)
Subject: Make BackgroundProcessor `#[must_use]` to avoid dropping immediately
X-Git-Tag: v0.0.100~9^2
X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=rust-lightning;a=commitdiff_plain;h=5307b5e8ceb2bb2ac9634eafd3c8b123d25da34f

Make BackgroundProcessor `#[must_use]` to avoid dropping immediately

It is easy for users to have a bug where they drop a
`BackgroundProcessor` immediately, causing it to start and then
immediately stop. Instead, add a `#[must_use]` tag to provide a
compiler warning for such instances.
---

diff --git a/lightning-background-processor/src/lib.rs b/lightning-background-processor/src/lib.rs
index 55ac14c0..afa3633b 100644
--- a/lightning-background-processor/src/lib.rs
+++ b/lightning-background-processor/src/lib.rs
@@ -39,6 +39,7 @@ use std::ops::Deref;
 /// 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 /// outdated.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.
+#[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
 pub struct BackgroundProcessor {
 	stop_thread: Arc<AtomicBool>,
 	thread_handle: Option<JoinHandle<Result<(), std::io::Error>>>,