perf: eliminate tokio::sync::Mutex across async boundaries in stub and nvim-core

nvim-core/src/lib.rs

@@ -150,8 +150,8 @@ async fn get_nvim_connection() -> Result<mpsc::Sender<NvimRequest>, String> {
 
     let (mut read_half, mut write_half) = tokio::io::split(stream);
     let (tx, mut rx) = mpsc::channel::<NvimRequest>(32);
-    type PendingRequestsMap = Arc<Mutex<HashMap<String, oneshot::Sender<Result<rmpv::Value, String>>>>>;
-    let pending_requests: PendingRequestsMap = Arc::new(Mutex::new(HashMap::new()));
+    type PendingRequestsMap = Arc<std::sync::Mutex<HashMap<String, oneshot::Sender<Result<rmpv::Value, String>>>>>;
+    let pending_requests: PendingRequestsMap = Arc::new(std::sync::Mutex::new(HashMap::new()));
 
     // Write task
     let pending_clone = Arc::clone(&pending_requests);
@@ -163,7 +163,7 @@ async fn get_nvim_connection() -> Result<mpsc::Sender<NvimRequest>, String> {
                 continue;
             }
             
-            pending_clone.lock().await.insert(req.msgid_str.clone(), req.reply);
+            pending_clone.lock().unwrap().insert(req.msgid_str.clone(), req.reply);
             
             if write_half.write_all(&buf).await.is_err() {
                 tracing::error!("Failed to write to Neovim socket");
@@ -190,7 +190,7 @@ async fn get_nvim_connection() -> Result<mpsc::Sender<NvimRequest>, String> {
                             let msgid = &arr[1];
                             let msgid_str = format!("{:?}", msgid);
                             
-                            if let Some(reply_sender) = pending_clone2.lock().await.remove(&msgid_str) {
+                            if let Some(reply_sender) = pending_clone2.lock().unwrap().remove(&msgid_str) {
                                 let _ = reply_sender.send(Ok(val));
                             }
                         }
@@ -225,7 +225,7 @@ async fn get_nvim_connection() -> Result<mpsc::Sender<NvimRequest>, String> {
         }
         
         // Cleanup pending requests on disconnect
-        let mut pending = pending_clone2.lock().await;
+        let mut pending = pending_clone2.lock().unwrap();
         for (_, sender) in pending.drain() {
             let _ = sender.send(Err("Connection closed".to_string()));
         }
@@ -240,7 +240,7 @@ async fn get_nvim_connection() -> Result<mpsc::Sender<NvimRequest>, String> {
             if Arc::strong_count(&pending_clone3) <= 1 {
                 break; // Socket closed and other tasks finished, no need to keep cleaning up
             }
-            pending_clone3.lock().await.retain(|_, sender| !sender.is_closed());
+            pending_clone3.lock().unwrap().retain(|_, sender| !sender.is_closed());
         }
     });