Revert "beefy: Avoid double lock wrt live peers and cache reset"

This reverts commit 7c77d4e.

Signed-off-by: Alexandru Vasile <[email protected]>

substrate/client/consensus/beefy/src/communication/request_response/outgoing_requests_engine.rs

@@ -98,17 +98,12 @@ impl<B: Block, AuthorityId: AuthorityIdBound> OnDemandJustificationsEngine<B, Au
 		}
 	}
 
-	/// Returns the next peer from the peers cache, if available.
-	///
-	/// If the optional block number if provided, the peers cache is
-	/// repopulated from the live peers that have voted on higher block numbers.
-	fn try_next_peer(&mut self, reset_cache: Option<NumberFor<B>>) -> Option<PeerId> {
-		let live = self.live_peers.lock();
-
-		if let Some(reset) = reset_cache {
-			self.peers_cache = live.further_than(reset);
-		}
+	fn reset_peers_cache_for_block(&mut self, block: NumberFor<B>) {
+		self.peers_cache = self.live_peers.lock().further_than(block);
+	}
 
+	fn try_next_peer(&mut self) -> Option<PeerId> {
+		let live = self.live_peers.lock();
 		while let Some(peer) = self.peers_cache.pop_front() {
 			if live.contains(&peer) {
 				return Some(peer);
@@ -147,10 +142,11 @@ impl<B: Block, AuthorityId: AuthorityIdBound> OnDemandJustificationsEngine<B, Au
 		if matches!(self.state, State::AwaitingResponse(_, _, _)) {
 			return;
 		}
+		self.reset_peers_cache_for_block(block);
 
 		// Start the requests engine - each unsuccessful received response will automatically
 		// trigger a new request to the next peer in the `peers_cache` until there are none left.
-		if let Some(peer) = self.try_next_peer(Some(block)) {
+		if let Some(peer) = self.try_next_peer() {
 			self.request_from_peer(peer, RequestInfo { block, active_set });
 		} else {
 			metric_inc!(self.metrics, beefy_on_demand_justification_no_peer_to_request_from);
@@ -250,7 +246,7 @@ impl<B: Block, AuthorityId: AuthorityIdBound> OnDemandJustificationsEngine<B, Au
 		match self.process_response(&peer, &req_info, resp) {
 			Err(err) => {
 				// No valid justification received, try next peer in our set.
-				if let Some(peer) = self.try_next_peer(None) {
+				if let Some(peer) = self.try_next_peer() {
 					self.request_from_peer(peer, req_info);
 				} else {
 					metric_inc!(