From f1c28f497f3e8450d9c5f3c01afc3af3e50d1f27 Mon Sep 17 00:00:00 2001
From: dapplion <35266934+dapplion@users.noreply.github.com>
Date: Wed, 15 Nov 2023 19:47:41 +0300
Subject: [PATCH] use dedicated channel

---
 beacon_node/beacon_chain/src/beacon_chain.rs | 14 ++++++++++++++
 beacon_node/beacon_chain/src/builder.rs      | 16 +++++++++++++++-
 beacon_node/client/src/builder.rs            |  2 +-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index 588506459ab..66fe7c85d31 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -289,6 +289,8 @@ struct PartialBeaconBlock<E: EthSpec, Payload: AbstractExecPayload<E>> {
     bls_to_execution_changes: Vec<SignedBlsToExecutionChange>,
 }
 
+pub type LightclientProducerEvent<T: EthSpec> = (Hash256, Slot, SyncAggregate<T>);
+
 pub type BeaconForkChoice<T> = ForkChoice<
     BeaconForkChoiceStore<
         <T as BeaconChainTypes>::EthSpec,
@@ -410,6 +412,8 @@ pub struct BeaconChain<T: BeaconChainTypes> {
     pub pre_finalization_block_cache: PreFinalizationBlockCache,
     /// A cache used to produce lightclient server messages
     pub lightclient_server_cache: LightclientServerCache<T>,
+    /// Sender to signal the lightclient server to produce new updates
+    pub lightclient_server_tx: Option<Sender<LightclientProducerEvent<T::EthSpec>>>,
     /// Sender given to tasks, so that if they encounter a state in which execution cannot
     /// continue they can request that everything shuts down.
     pub shutdown_sender: Sender<ShutdownReason>,
@@ -3477,6 +3481,16 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 }));
             }
         }
+
+        if let Some(lightclient_server_tx) = self.lightclient_server_tx {
+            if let Ok(sync_aggregate) = block.body().sync_aggregate() {
+                lightclient_server_tx.try_send((
+                    block.parent_root(),
+                    block.slot(),
+                    sync_aggregate.clone(),
+                ));
+            }
+        }
     }
 
     // For the current and next epoch of this state, ensure we have the shuffling from this
diff --git a/beacon_node/beacon_chain/src/builder.rs b/beacon_node/beacon_chain/src/builder.rs
index 1076a433344..c3e46d3d15d 100644
--- a/beacon_node/beacon_chain/src/builder.rs
+++ b/beacon_node/beacon_chain/src/builder.rs
@@ -1,4 +1,6 @@
-use crate::beacon_chain::{CanonicalHead, BEACON_CHAIN_DB_KEY, ETH1_CACHE_DB_KEY, OP_POOL_DB_KEY};
+use crate::beacon_chain::{
+    CanonicalHead, LightclientProducerEvent, BEACON_CHAIN_DB_KEY, ETH1_CACHE_DB_KEY, OP_POOL_DB_KEY,
+};
 use crate::eth1_chain::{CachingEth1Backend, SszEth1};
 use crate::eth1_finalization_cache::Eth1FinalizationCache;
 use crate::fork_choice_signal::ForkChoiceSignalTx;
@@ -84,6 +86,7 @@ pub struct BeaconChainBuilder<T: BeaconChainTypes> {
     event_handler: Option<ServerSentEventHandler<T::EthSpec>>,
     slot_clock: Option<T::SlotClock>,
     shutdown_sender: Option<Sender<ShutdownReason>>,
+    lightclient_server_tx: Option<Sender<LightclientProducerEvent<T::EthSpec>>>,
     head_tracker: Option<HeadTracker>,
     validator_pubkey_cache: Option<ValidatorPubkeyCache<T>>,
     spec: ChainSpec,
@@ -125,6 +128,7 @@ where
             event_handler: None,
             slot_clock: None,
             shutdown_sender: None,
+            lightclient_server_tx: None,
             head_tracker: None,
             validator_pubkey_cache: None,
             spec: TEthSpec::default_spec(),
@@ -561,6 +565,15 @@ where
         self
     }
 
+    /// Sets a `Sender` to allow the beacon chain to send shutdown signals.
+    pub fn lightclient_server_tx(
+        mut self,
+        sender: Sender<LightclientProducerEvent<TEthSpec>>,
+    ) -> Self {
+        self.lightclient_server_tx = Some(sender);
+        self
+    }
+
     /// Creates a new, empty operation pool.
     fn empty_op_pool(mut self) -> Self {
         self.op_pool = Some(OperationPool::new());
@@ -861,6 +874,7 @@ where
             attester_cache: <_>::default(),
             early_attester_cache: <_>::default(),
             lightclient_server_cache: LightclientServerCache::new(),
+            lightclient_server_tx: self.lightclient_server_tx,
             shutdown_sender: self
                 .shutdown_sender
                 .ok_or("Cannot build without a shutdown sender.")?,
diff --git a/beacon_node/client/src/builder.rs b/beacon_node/client/src/builder.rs
index 545a28a9651..d333d4e1576 100644
--- a/beacon_node/client/src/builder.rs
+++ b/beacon_node/client/src/builder.rs
@@ -838,7 +838,7 @@ where
                     let broadcast_context =
                         runtime_context.service_context("lcserv_bcast".to_string());
                     let log = broadcast_context.log().clone();
-                    broadcast_context.executor.spawn(
+                    broadcast_context.executor.spawn_blocking(
                         async move {
                             broadcast_lightclient_updates(
                                 &inner_chain,