Return splittable error from executor params request fn

node/core/pvf-checker/src/lib.rs

@@ -20,7 +20,7 @@
 //! as well as submitting statements regarding them passing or not the PVF pre-checking.
 
 use futures::{channel::oneshot, future::BoxFuture, prelude::*, stream::FuturesUnordered};
-use polkadot_node_subsystem_util::{executor_params_at_relay_parent, Error};
+use polkadot_node_subsystem_util::{executor_params_at_relay_parent, runtime::Error};
 
 use polkadot_node_subsystem::{
 	messages::{CandidateValidationMessage, PreCheckOutcome, PvfCheckerMessage, RuntimeApiMessage},
@@ -540,14 +540,15 @@ async fn initiate_precheck(
 	let executor_params = match executor_params_at_relay_parent(relay_parent, sender).await {
 		Ok(executor_params) => executor_params,
 		Err(err) => {
-			// Error::Oneshot indicates a failure to communicate with the runtime (probably
-			// being shut down). Error::RuntimeApi is a failure to acquire either session
+			// Error::RuntimeRequestCanceled indicates a failure to communicate with the runtime
+			// (probably being shut down). Error::RuntimeApi is a failure to acquire either session
 			// index or executor params for the session which indicates a permanent failure to
 			// run pre-checking on the code provided.
 			state.currently_checking.push(Box::pin(async move {
 				match err {
-					Error::RuntimeApi(_) => Some((PreCheckOutcome::Failed, validation_code_hash)),
-					Error::Oneshot(_) => None,
+					Error::RuntimeRequest(_) =>
+						Some((PreCheckOutcome::Failed, validation_code_hash)),
+					Error::RuntimeRequestCanceled(_) => None,
 					_ => unreachable!(), // The callee never generates other error types
 				}
 			}));

node/subsystem-util/src/lib.rs

@@ -24,6 +24,7 @@
 
 #![warn(missing_docs)]
 
+use crate::runtime::Error as SubsysUtilError;
 use polkadot_node_subsystem::{
 	errors::{RuntimeApiError, SubsystemError},
 	messages::{RuntimeApiMessage, RuntimeApiRequest, RuntimeApiSender},
@@ -219,21 +220,21 @@ specialize_requests! {
 pub async fn executor_params_at_relay_parent(
 	relay_parent: Hash,
 	sender: &mut impl overseer::SubsystemSender<RuntimeApiMessage>,
-) -> Result<ExecutorParams, Error> {
+) -> Result<ExecutorParams, SubsysUtilError> {
 	match request_session_index_for_child(relay_parent, sender).await.await {
 		Err(err) => {
 			// Failed to communicate with the runtime
-			Err(Error::Oneshot(err))
+			Err(SubsysUtilError::RuntimeRequestCanceled(err))
 		},
 		Ok(Err(err)) => {
 			// Runtime has failed to obtain a session index at the relay-parent; should never happen
-			Err(Error::RuntimeApi(err))
+			Err(SubsysUtilError::RuntimeRequest(err))
 		},
 		Ok(Ok(session_index)) => {
 			match request_session_executor_params(relay_parent, session_index, sender).await.await {
 				Err(err) => {
 					// Failed to communicate with the runtime
-					Err(Error::Oneshot(err))
+					Err(SubsysUtilError::RuntimeRequestCanceled(err))
 				},
 				Ok(Err(_)) => {
 					// Runtime doesn't yet support the api requested, should execute anyway
@@ -243,7 +244,7 @@ pub async fn executor_params_at_relay_parent(
 				Ok(Ok(None)) => {
 					// Storage doesn't contain a parameter set for the given session; should
 					// never happen
-					Err(Error::RuntimeApi(RuntimeApiError::NotSupported {
+					Err(SubsysUtilError::RuntimeRequest(RuntimeApiError::NotSupported {
 						runtime_api_name: "SessionExecutorParams",
 					}))
 				},