From a35415d1471e4a3be4c05d7a951eff5d1147309d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Silva?= <andrerfosilva@gmail.com>
Date: Sat, 27 Mar 2021 13:03:12 +0000
Subject: [PATCH] slots: remove mutex around BlockImport in SlotWorker

---
 Cargo.lock                        |  1 -
 client/consensus/aura/src/lib.rs  | 13 ++++++-------
 client/consensus/babe/src/lib.rs  |  8 ++++----
 client/consensus/slots/Cargo.toml |  1 -
 client/consensus/slots/src/lib.rs |  6 ++----
 5 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index d41c255e3a8d7..3602f0cac5ce9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7318,7 +7318,6 @@ dependencies = [
  "futures-timer 3.0.2",
  "log",
  "parity-scale-codec 2.0.1",
- "parking_lot 0.11.1",
  "sc-client-api",
  "sc-telemetry",
  "sp-api",
diff --git a/client/consensus/aura/src/lib.rs b/client/consensus/aura/src/lib.rs
index 81c6015ac7efa..cc60406d1664b 100644
--- a/client/consensus/aura/src/lib.rs
+++ b/client/consensus/aura/src/lib.rs
@@ -35,7 +35,6 @@ use std::{
 };
 
 use futures::prelude::*;
-use parking_lot::Mutex;
 use log::{debug, trace};
 
 use codec::{Encode, Decode, Codec};
@@ -272,7 +271,7 @@ pub fn build_aura_worker<P, B, C, PF, I, SO, BS, Error>(
 {
 	AuraWorker {
 		client,
-		block_import: Arc::new(Mutex::new(block_import)),
+		block_import,
 		env: proposer_factory,
 		keystore,
 		sync_oracle,
@@ -286,7 +285,7 @@ pub fn build_aura_worker<P, B, C, PF, I, SO, BS, Error>(
 
 struct AuraWorker<C, E, I, P, SO, BS> {
 	client: Arc<C>,
-	block_import: Arc<Mutex<I>>,
+	block_import: I,
 	env: E,
 	keystore: SyncCryptoStorePtr,
 	sync_oracle: SO,
@@ -326,8 +325,8 @@ where
 		"aura"
 	}
 
-	fn block_import(&self) -> Arc<Mutex<Self::BlockImport>> {
-		self.block_import.clone()
+	fn block_import(&mut self) -> &mut Self::BlockImport {
+		&mut self.block_import
 	}
 
 	fn epoch_data(
@@ -805,7 +804,7 @@ mod tests {
 
 		let worker = AuraWorker {
 			client: client.clone(),
-			block_import: Arc::new(Mutex::new(client)),
+			block_import: client,
 			env: environ,
 			keystore: keystore.into(),
 			sync_oracle: DummyOracle.clone(),
@@ -854,7 +853,7 @@ mod tests {
 
 		let mut worker = AuraWorker {
 			client: client.clone(),
-			block_import: Arc::new(Mutex::new(client.clone())),
+			block_import: client.clone(),
 			env: environ,
 			keystore: keystore.into(),
 			sync_oracle: DummyOracle.clone(),
diff --git a/client/consensus/babe/src/lib.rs b/client/consensus/babe/src/lib.rs
index 14ac2ebbcf2a4..28cfec1238e42 100644
--- a/client/consensus/babe/src/lib.rs
+++ b/client/consensus/babe/src/lib.rs
@@ -448,7 +448,7 @@ pub fn start_babe<B, C, SC, E, I, SO, CAW, BS, Error>(BabeParams {
 
 	let worker = BabeSlotWorker {
 		client: client.clone(),
-		block_import: Arc::new(Mutex::new(block_import)),
+		block_import,
 		env,
 		sync_oracle: sync_oracle.clone(),
 		force_authoring,
@@ -605,7 +605,7 @@ type SlotNotificationSinks<B> = Arc<
 
 struct BabeSlotWorker<B: BlockT, C, E, I, SO, BS> {
 	client: Arc<C>,
-	block_import: Arc<Mutex<I>>,
+	block_import: I,
 	env: E,
 	sync_oracle: SO,
 	force_authoring: bool,
@@ -647,8 +647,8 @@ where
 		"babe"
 	}
 
-	fn block_import(&self) -> Arc<Mutex<Self::BlockImport>> {
-		self.block_import.clone()
+	fn block_import(&mut self) -> &mut Self::BlockImport {
+		&mut self.block_import
 	}
 
 	fn epoch_data(
diff --git a/client/consensus/slots/Cargo.toml b/client/consensus/slots/Cargo.toml
index 623c4c4abd84c..64beea50fcf63 100644
--- a/client/consensus/slots/Cargo.toml
+++ b/client/consensus/slots/Cargo.toml
@@ -31,7 +31,6 @@ sp-inherents = { version = "3.0.0", path = "../../../primitives/inherents" }
 sp-timestamp = { version = "3.0.0", path = "../../../primitives/timestamp" }
 futures = "0.3.9"
 futures-timer = "3.0.1"
-parking_lot = "0.11.1"
 log = "0.4.11"
 thiserror = "1.0.21"
 async-trait = "0.1.42"
diff --git a/client/consensus/slots/src/lib.rs b/client/consensus/slots/src/lib.rs
index dbf62ccad23c8..351ef932ada19 100644
--- a/client/consensus/slots/src/lib.rs
+++ b/client/consensus/slots/src/lib.rs
@@ -32,12 +32,11 @@ pub use slots::SlotInfo;
 use slots::Slots;
 pub use aux_schema::{check_equivocation, MAX_SLOT_CAPACITY, PRUNING_BOUND};
 
-use std::{fmt::Debug, ops::Deref, sync::Arc, time::Duration};
+use std::{fmt::Debug, ops::Deref, time::Duration};
 use codec::{Decode, Encode};
 use futures::{future::Either, Future, TryFutureExt};
 use futures_timer::Delay;
 use log::{debug, error, info, warn};
-use parking_lot::Mutex;
 use sp_api::{ProvideRuntimeApi, ApiRef};
 use sp_arithmetic::traits::BaseArithmetic;
 use sp_consensus::{BlockImport, Proposer, SyncOracle, SelectChain, CanAuthorWith, SlotData};
@@ -110,7 +109,7 @@ pub trait SimpleSlotWorker<B: BlockT> {
 	fn logging_target(&self) -> &'static str;
 
 	/// A handle to a `BlockImport`.
-	fn block_import(&self) -> Arc<Mutex<Self::BlockImport>>;
+	fn block_import(&mut self) -> &mut Self::BlockImport;
 
 	/// Returns the epoch data necessary for authoring. For time-dependent epochs,
 	/// use the provided slot number as a canonical source of time.
@@ -398,7 +397,6 @@ pub trait SimpleSlotWorker<B: BlockT> {
 
 		let header = block_import_params.post_header();
 		if let Err(err) = block_import
-			.lock()
 			.import_block(block_import_params, Default::default())
 		{
 			warn!(