Make sentiment predictions blocking

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/threads/data/backfill.rs

@@ -20,7 +20,7 @@ use time::OffsetDateTime;
 use tokio::{
     join, spawn,
     sync::{mpsc, oneshot, Mutex, RwLock},
-    task::JoinHandle,
+    task::{block_in_place, JoinHandle},
     time::sleep,
 };
 
@@ -397,13 +397,14 @@ async fn execute_backfill_news(
     let predictions = join_all(inputs.chunks(app_config.max_bert_inputs).map(|inputs| {
         let sequence_classifier = app_config.sequence_classifier.clone();
         async move {
+            let sequence_classifier = sequence_classifier.lock().await;
+            block_in_place(|| {
                 sequence_classifier
-                .lock()
-                .await
                     .predict(inputs.iter().map(String::as_str).collect::<Vec<_>>())
                     .into_iter()
                     .map(|label| Prediction::try_from(label).unwrap())
                     .collect::<Vec<_>>()
+            })
         }
     }))
     .await

src/threads/data/websocket.rs

@@ -17,6 +17,7 @@ use tokio::{
     net::TcpStream,
     spawn,
     sync::{mpsc, Mutex, RwLock},
+    task::block_in_place,
 };
 use tokio_tungstenite::{tungstenite, MaybeTlsStream, WebSocketStream};
 
@@ -209,14 +210,15 @@ async fn handle_parsed_websocket_message(
 
             let input = format!("{}\n\n{}", news.headline, news.content);
 
-            let prediction = app_config
+            let sequence_classifier = app_config.sequence_classifier.lock().await;
-                .sequence_classifier
+            let prediction = block_in_place(|| {
-                .lock()
+                sequence_classifier
-                .await
                     .predict(vec![input.as_str()])
                     .into_iter()
                     .map(|label| Prediction::try_from(label).unwrap())
-                .collect::<Vec<_>>()[0];
+                    .collect::<Vec<_>>()[0]
+            });
+            drop(sequence_classifier);
 
             let news = News {
                 sentiment: prediction.sentiment,