removes repeated bank-forks locking in window-service

Window service is repeatedly locking bank-forks to look-up working-bank
for every single shred:
https://github.com/solana-labs/solana/blob/5fde4ee3a/core/src/window_service.rs#L597-L606

This commit updates shred_filter signature in recv_window so that where
we already obtain the lock on bank-forks, we can also look-up
working-bank once for all packets:
https://github.com/solana-labs/solana/blob/5fde4ee3a/core/src/window_service.rs#L256-L277

core/src/window_service.rs

@@ -5,7 +5,6 @@ use crate::{
     ancestor_hashes_service::AncestorHashesReplayUpdateReceiver,
     cluster_info_vote_listener::VerifiedVoteReceiver,
     completed_data_sets_service::CompletedDataSetsSender,
-    outstanding_requests::OutstandingRequests,
     repair_response,
     repair_service::{OutstandingShredRepairs, RepairInfo, RepairService},
     result::{Error, Result},
@@ -88,10 +87,7 @@ pub fn should_retransmit_and_persist(
     root: u64,
     shred_version: u16,
 ) -> bool {
-    let slot_leader_pubkey = match bank {
-        None => leader_schedule_cache.slot_leader_at(shred.slot(), None),
-        Some(bank) => leader_schedule_cache.slot_leader_at(shred.slot(), Some(&bank)),
-    };
+    let slot_leader_pubkey = leader_schedule_cache.slot_leader_at(shred.slot(), bank.as_deref());
     if let Some(leader_id) = slot_leader_pubkey {
         if leader_id == *my_pubkey {
             inc_new_counter_debug!("streamer-recv_window-circular_transmission", 1);
@@ -265,7 +261,7 @@ fn recv_window<F>(
     thread_pool: &ThreadPool,
 ) -> Result<()>
 where
-    F: Fn(&Shred, u64) -> bool + Sync,
+    F: Fn(&Shred, Arc<Bank>, /*last root:*/ Slot) -> bool + Sync,
 {
     let timer = Duration::from_millis(200);
     let mut packets = verified_receiver.recv_timeout(timer)?;
@@ -274,7 +270,10 @@ where
     let now = Instant::now();
     inc_new_counter_debug!("streamer-recv_window-recv", total_packets);
 
-    let root_bank = bank_forks.read().unwrap().root_bank();
+    let (root_bank, working_bank) = {
+        let bank_forks = bank_forks.read().unwrap();
+        (bank_forks.root_bank(), bank_forks.working_bank())
+    };
     let last_root = blockstore.last_root();
     let handle_packet = |packet: &mut Packet| {
         if packet.meta.discard {
@@ -286,8 +285,9 @@ where
         // call to `new_from_serialized_shred` is safe.
         assert_eq!(packet.data.len(), PACKET_DATA_SIZE);
         let serialized_shred = packet.data.to_vec();
+        let working_bank = Arc::clone(&working_bank);
         let shred = match Shred::new_from_serialized_shred(serialized_shred) {
-            Ok(shred) if shred_filter(&shred, last_root) => {
+            Ok(shred) if shred_filter(&shred, working_bank, last_root) => {
                 let leader_pubkey =
                     leader_schedule_cache.slot_leader_at(shred.slot(), Some(root_bank.deref()));
                 packet.meta.slot = shred.slot();
@@ -386,12 +386,11 @@ impl WindowService {
     ) -> WindowService
     where
         F: 'static
-            + Fn(&Pubkey, &Shred, Option<Arc<Bank>>, u64) -> bool
+            + Fn(&Pubkey, &Shred, Option<Arc<Bank>>, /*last root:*/ Slot) -> bool
             + std::marker::Send
             + std::marker::Sync,
     {
-        let outstanding_requests: Arc<RwLock<OutstandingShredRepairs>> =
-            Arc::new(RwLock::new(OutstandingRequests::default()));
+        let outstanding_requests = Arc::<RwLock<OutstandingShredRepairs>>::default();
 
         let bank_forks = repair_info.bank_forks.clone();
         let cluster_info = repair_info.cluster_info.clone();
@@ -559,7 +558,6 @@ impl WindowService {
         let exit = exit.clone();
         let blockstore = blockstore.clone();
         let bank_forks = bank_forks.clone();
-        let bank_forks_opt = Some(bank_forks.clone());
         let leader_schedule_cache = leader_schedule_cache.clone();
         Builder::new()
             .name("solana-window".to_string())
@@ -594,13 +592,11 @@ impl WindowService {
                         &id,
                         &verified_receiver,
                         &retransmit,
-                        |shred, last_root| {
+                        |shred, bank, last_root| {
                             shred_filter(
                                 &id,
                                 shred,
-                                bank_forks_opt
-                                    .as_ref()
-                                    .map(|bank_forks| bank_forks.read().unwrap().working_bank()),
+                                Some(bank),
                                 last_root,
                             )
                         },