From 6b3b2b759a1f07f682c749e2e1d22e23eea2f797 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Wed, 22 Jun 2022 16:17:50 +1000
Subject: [PATCH] Tidy

---
 beacon_node/beacon_chain/src/beacon_chain.rs      | 15 +++++++--------
 .../beacon_chain/src/block_verification.rs        |  4 +---
 .../src/beacon_processor/worker/gossip_methods.rs |  9 ---------
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index d8b48549f28..4dce61758ad 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -1434,8 +1434,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         let beacon_block_root;
         let beacon_state_root;
         let head_timer = metrics::start_timer(&metrics::ATTESTATION_PRODUCTION_HEAD_SCRAPE_SECONDS);
-        let cached_head_lock = self.canonical_head.cached_head();
-        let head = &cached_head_lock.snapshot;
+        let cached_head = self.canonical_head.cached_head();
+        let head = &cached_head.snapshot;
         let head_state = &head.beacon_state;
         let head_state_slot = head_state.slot();
 
@@ -1511,8 +1511,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             AttesterCacheKey::new(request_epoch, head_state, beacon_block_root)?;
         drop(head_timer);
 
-        // Drop the head lock ASAP to prevent lock contention.
-        drop(cached_head_lock);
+        // Drop the `Arc` to avoid keeping the reference alive any longer than required.
+        drop(cached_head);
 
         // Only attest to a block if it is fully verified (i.e. not optimistic or invalid).
         match self
@@ -2356,11 +2356,10 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         let block = unverified_block.block().clone();
 
         // A small closure to group the verification and import errors.
-        let chain_a = self.clone();
-        let chain_b = self.clone();
+        let chain = self.clone();
         let import_block = async move {
-            let execution_pending = unverified_block.into_execution_pending_block(&chain_a)?;
-            chain_b
+            let execution_pending = unverified_block.into_execution_pending_block(&chain)?;
+            chain
                 .import_execution_pending_block(execution_pending)
                 .await
         };
diff --git a/beacon_node/beacon_chain/src/block_verification.rs b/beacon_node/beacon_chain/src/block_verification.rs
index 82ba5545ac3..5c67f272ba3 100644
--- a/beacon_node/beacon_chain/src/block_verification.rs
+++ b/beacon_node/beacon_chain/src/block_verification.rs
@@ -277,9 +277,6 @@ pub enum BlockError<T: EthSpec> {
     /// The peer sent us an invalid block, but I'm not really sure how to score this in an
     /// "optimistic" sync world.
     ParentExecutionPayloadInvalid { parent_root: Hash256 },
-    /// A block import was cancelled. This error should never be surfaced, it indicates an error in
-    /// our programming.
-    BlockImportCancelled,
 }
 
 /// Returned when block validation failed due to some issue verifying
@@ -425,6 +422,7 @@ impl<T: EthSpec> From<ArithError> for BlockError<T> {
     }
 }
 
+/// Stores information about verifying a payload against an execution engine.
 pub struct PayloadVerificationOutcome {
     pub payload_verification_status: PayloadVerificationStatus,
     pub is_valid_merge_transition_block: bool,
diff --git a/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs b/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
index c90771be310..a9db31e15c1 100644
--- a/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
+++ b/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
@@ -754,15 +754,6 @@ impl<T: BeaconChainTypes> Worker<T> {
                 self.send_sync_message(SyncMessage::UnknownBlock(peer_id, block));
                 return None;
             }
-            Err(e @ BlockError::BlockImportCancelled) => {
-                crit!(
-                    self.log,
-                    "Unexpected block import error";
-                    "error" => ?e,
-                );
-                self.propagate_validation_result(message_id, peer_id, MessageAcceptance::Ignore);
-                return None;
-            }
             Err(e @ BlockError::BeaconChainError(_)) => {
                 debug!(
                     self.log,