state: Send a warning trace whenever the state db lock is poisoned

src/state.rs

@@ -19,13 +19,13 @@
 
 use std::{
     error::Error,
-    sync::{Arc, Mutex}
+    sync::{Arc, Mutex, MutexGuard}
 };
 
 use tokio::fs;
 
 use chrono::{ DateTime, Utc };
-use tracing::{ info, debug };
+use tracing::{ warn, info, debug };
 
 use serde_yaml::mapping::Mapping as FeedReaderState;
 
@@ -48,6 +48,13 @@ impl FeedReaderStateDb {
         Ok(db.clone())
     }
 
+    fn lock_state(&self) -> MutexGuard<FeedReaderState> {
+        self.state.lock().unwrap_or_else(|e| {
+            warn!("State db mutex has been poisoned, continuing...");
+            e.into_inner()
+        })
+    }
+
     pub async fn set(
         &self,
         uri: &str,
@@ -56,7 +63,7 @@ impl FeedReaderStateDb {
 
         {
             debug!("Updating feed reader state");
-            self.state.lock().unwrap().insert(uri.into(), dt.timestamp().into());
+            self.lock_state().insert(uri.into(), dt.timestamp().into());
         }
 
         self.persist().await.unwrap();
@@ -65,7 +72,7 @@ impl FeedReaderStateDb {
     #[tracing::instrument(ret, level="debug")]
     pub fn get(&self, uri: &str) -> Option<DateTime<Utc>> {
         debug!("Retrieving state for feed {}", uri);
-        match self.state.lock().unwrap().get(uri) {
+        match self.lock_state().get(uri) {
             Some(t) => DateTime::from_timestamp((*t).as_i64().unwrap(), 0),
             None => None
         }