[parallel] Wrap Blocking Calls in Async

consensus/src/marshal/coding/marshaled.rs

@@ -799,12 +799,25 @@ where
             };
             build_timer.observe(&runtime_context);
 
+            let round = consensus_context.round;
             let erasure_timer = erasure_encode_duration.timer(&runtime_context);
-            let coded_block = CodedBlock::<B, C, H>::new(built_block, coding_config, &strategy);
+            let handle = runtime_context
+                .child("erasure_encode")
+                .with_attribute("round", round)
+                .shared(true)
+                .spawn(move |_| async move {
+                    CodedBlock::<B, C, H>::new(built_block, coding_config, &strategy)
+                });
+            let coded_block = select! {
+                _ = tx.closed() => {
+                    debug!(reason = "consensus dropped receiver", "skipping proposal");
+                    return;
+                },
+                result = handle => result.expect("strategy task failed"),
+            };
             erasure_timer.observe(&runtime_context);
 
             let commitment = coded_block.commitment();
-            let round = consensus_context.round;
             if !marshal.proposed(round, coded_block).await {
                 debug!(?round, ?commitment, "marshal rejected proposed block");
                 return;