fix: used to hold non-yield-safe references across yields

src/traft/network.rs

@@ -224,8 +224,6 @@ impl PoolWorker {
             poll_fn(|cx| {
                 let mut has_ready: bool = false;
                 let mut cursor = 0;
-                // NOTE: must not yield until this is dropped.
-                let mut reachability = instance_reachability.borrow_mut();
                 while cursor < futures.len() {
                     let poll_result = Future::poll(futures[cursor].2.as_mut(), cx);
                     if let Poll::Ready(result) = poll_result {
@@ -260,7 +258,9 @@ impl PoolWorker {
                                             | TOError::Failed(NetError::Io(_))
                                     );
                                 }
-                                reachability.report_result(raft_id, success);
+                                instance_reachability
+                                    .borrow_mut()
+                                    .report_result(raft_id, success);
                             }
                         }
                         has_ready = true;

src/traft/node.rs

@@ -1403,13 +1403,13 @@ impl NodeImpl {
         let mut sent_count = 0;
         let mut skip_count = 0;
 
-        let instance_reachability = self.instance_reachability.borrow();
         for msg in messages {
-            if msg.msg_type == raft::MessageType::MsgHeartbeat
-                && !instance_reachability.should_send_heartbeat_this_tick(msg.to)
-            {
-                skip_count += 1;
-                continue;
+            if msg.msg_type == raft::MessageType::MsgHeartbeat {
+                let instance_reachability = self.instance_reachability.borrow();
+                if !instance_reachability.should_send_heartbeat_this_tick(msg.to) {
+                    skip_count += 1;
+                    continue;
+                }
             }
             sent_count += 1;
             if let Err(e) = self.pool.send(msg) {