Limit leader schedule search space (#8468)

* Limit leader schedule search space

* Fix and add test

* Rename

core/src/poh_recorder.rs

@@ -28,8 +28,8 @@ use std::sync::{Arc, Mutex};
 use std::time::Instant;
 use thiserror::Error;
 
-const GRACE_TICKS_FACTOR: u64 = 2;
-const MAX_GRACE_SLOTS: u64 = 2;
+pub const GRACE_TICKS_FACTOR: u64 = 2;
+pub const MAX_GRACE_SLOTS: u64 = 2;
 
 #[derive(Error, Debug, Clone)]
 pub enum PohRecorderError {
@@ -85,6 +85,7 @@ impl PohRecorder {
                 bank.slot(),
                 &bank,
                 Some(&self.blockstore),
+                GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
             );
             assert_eq!(self.ticks_per_slot, bank.ticks_per_slot());
             let (leader_first_tick_height, leader_last_tick_height, grace_ticks) =

core/src/replay_stage.rs

@@ -4,7 +4,7 @@ use crate::{
     cluster_info::ClusterInfo,
     commitment::{AggregateCommitmentService, BlockCommitmentCache, CommitmentAggregationData},
     consensus::{StakeLockout, Tower},
-    poh_recorder::PohRecorder,
+    poh_recorder::{PohRecorder, GRACE_TICKS_FACTOR, MAX_GRACE_SLOTS},
     result::Result,
     rewards_recorder_service::RewardsRecorderSender,
     rpc_subscriptions::RpcSubscriptions,
@@ -683,6 +683,7 @@ impl ReplayStage {
             bank.slot(),
             &bank,
             Some(blockstore),
+            GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
         );
         poh_recorder
             .lock()

core/src/validator.rs

@@ -6,7 +6,7 @@ use crate::{
     commitment::BlockCommitmentCache,
     contact_info::ContactInfo,
     gossip_service::{discover_cluster, GossipService},
-    poh_recorder::PohRecorder,
+    poh_recorder::{PohRecorder, GRACE_TICKS_FACTOR, MAX_GRACE_SLOTS},
     poh_service::PohService,
     rewards_recorder_service::RewardsRecorderService,
     rpc::JsonRpcConfig,
@@ -304,7 +304,13 @@ impl Validator {
             bank.tick_height(),
             bank.last_blockhash(),
             bank.slot(),
-            leader_schedule_cache.next_leader_slot(&id, bank.slot(), &bank, Some(&blockstore)),
+            leader_schedule_cache.next_leader_slot(
+                &id,
+                bank.slot(),
+                &bank,
+                Some(&blockstore),
+                GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
+            ),
             bank.ticks_per_slot(),
             &id,
             &blockstore,