Send recent votes in Vote Transactions (#3734)

core/src/entry.rs

@@ -475,7 +475,7 @@ mod tests {
 
     fn create_sample_vote(keypair: &Keypair, hash: Hash) -> Transaction {
         let pubkey = keypair.pubkey();
-        let ix = vote_instruction::vote(&pubkey, Vote::new(1));
+        let ix = vote_instruction::vote(&pubkey, vec![Vote::new(1)]);
         Transaction::new_signed_instructions(&[keypair], vec![ix], hash)
     }
 

core/src/fullnode.rs

@@ -347,7 +347,8 @@ pub fn make_active_set_entries(
     let new_vote_account_entry = next_entry_mut(&mut last_entry_hash, 1, vec![new_vote_account_tx]);
 
     // 3) Create vote entry
-    let vote_ix = vote_instruction::vote(&voting_keypair.pubkey(), Vote::new(slot_to_vote_on));
+    let vote_ix =
+        vote_instruction::vote(&voting_keypair.pubkey(), vec![Vote::new(slot_to_vote_on)]);
     let vote_tx =
         Transaction::new_signed_instructions(&[&voting_keypair], vec![vote_ix], *blockhash);
     let vote_entry = next_entry_mut(&mut last_entry_hash, 1, vec![vote_tx]);

core/src/locktower.rs

@@ -10,6 +10,7 @@ use std::sync::Arc;
 
 pub const VOTE_THRESHOLD_DEPTH: usize = 8;
 pub const VOTE_THRESHOLD_SIZE: f64 = 2f64 / 3f64;
+const MAX_RECENT_VOTES: usize = 16;
 
 #[derive(Default)]
 pub struct EpochStakes {
@@ -253,6 +254,13 @@ impl Locktower {
         }
     }
 
+    pub fn recent_votes(&self) -> Vec<Vote> {
+        let start = self.lockouts.votes.len().saturating_sub(MAX_RECENT_VOTES);
+        (start..self.lockouts.votes.len())
+            .map(|i| Vote::new(self.lockouts.votes[i].slot))
+            .collect()
+    }
+
     pub fn root(&self) -> Option<u64> {
         self.lockouts.root_slot
     }
@@ -798,4 +806,29 @@ mod test {
             locktower.collect_vote_lockouts(vote_to_evaluate, accounts.into_iter(), &ancestors);
         assert!(!locktower.check_vote_stake_threshold(vote_to_evaluate, &stakes_lockouts));
     }
+
+    fn vote_and_check_recent(num_votes: usize) {
+        let mut locktower = Locktower::new(EpochStakes::new_for_tests(2), 1, 0.67);
+        let start = num_votes.saturating_sub(MAX_RECENT_VOTES);
+        let expected: Vec<_> = (start..num_votes).map(|i| Vote::new(i as u64)).collect();
+        for i in 0..num_votes {
+            locktower.record_vote(i as u64);
+        }
+        assert_eq!(expected, locktower.recent_votes())
+    }
+
+    #[test]
+    fn test_recent_votes_full() {
+        vote_and_check_recent(MAX_LOCKOUT_HISTORY)
+    }
+
+    #[test]
+    fn test_recent_votes_empty() {
+        vote_and_check_recent(0)
+    }
+
+    #[test]
+    fn test_recent_votes_exact() {
+        vote_and_check_recent(MAX_RECENT_VOTES)
+    }
 }

core/src/replay_stage.rs

@@ -22,7 +22,6 @@ use solana_sdk::signature::KeypairUtil;
 use solana_sdk::timing::{self, duration_as_ms};
 use solana_sdk::transaction::Transaction;
 use solana_vote_api::vote_instruction;
-use solana_vote_api::vote_state::Vote;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc::{channel, Receiver, RecvTimeoutError, Sender};
 use std::sync::{Arc, Mutex, RwLock};
@@ -294,24 +293,25 @@ impl ReplayStage {
         locktower: &mut Locktower,
         progress: &mut HashMap<u64, ForkProgress>,
         voting_keypair: &Option<Arc<T>>,
-        vote_account: &Pubkey,
+        vote_account_pubkey: &Pubkey,
         cluster_info: &Arc<RwLock<ClusterInfo>>,
         blocktree: &Arc<Blocktree>,
     ) where
         T: 'static + KeypairUtil + Send + Sync,
     {
         if let Some(ref voting_keypair) = voting_keypair {
-            let vote_ix = vote_instruction::vote(&vote_account, Vote::new(bank.slot()));
-            let vote_tx = Transaction::new_signed_instructions(
-                &[voting_keypair.as_ref()],
-                vec![vote_ix],
-                bank.last_blockhash(),
-            );
             if let Some(new_root) = locktower.record_vote(bank.slot()) {
                 bank_forks.write().unwrap().set_root(new_root);
                 blocktree.set_root(new_root);
                 Self::handle_new_root(&bank_forks, progress);
             }
+            // Send our last few votes along with the new one
+            let vote_ix = vote_instruction::vote(vote_account_pubkey, locktower.recent_votes());
+            let vote_tx = Transaction::new_signed_instructions(
+                &[voting_keypair.as_ref()],
+                vec![vote_ix],
+                bank.last_blockhash(),
+            );
             locktower.update_epoch(&bank);
             cluster_info.write().unwrap().push_vote(vote_tx);
         }
@@ -604,6 +604,7 @@ mod test {
     use solana_sdk::genesis_block::GenesisBlock;
     use solana_sdk::hash::Hash;
     use solana_sdk::signature::{Keypair, KeypairUtil};
+    use solana_vote_api::vote_state::Vote;
     use std::fs::remove_dir_all;
     use std::sync::mpsc::channel;
     use std::sync::{Arc, RwLock};
@@ -652,8 +653,7 @@ mod test {
                 &poh_recorder,
                 ledger_writer_sender,
             );
-
-            let vote_ix = vote_instruction::vote(&voting_keypair.pubkey(), Vote::new(0));
+            let vote_ix = vote_instruction::vote(&voting_keypair.pubkey(), vec![Vote::new(0)]);
             let vote_tx = Transaction::new_signed_instructions(
                 &[voting_keypair.as_ref()],
                 vec![vote_ix],

core/src/voting_keypair.rs

@@ -138,7 +138,7 @@ pub mod tests {
     }
 
     pub fn push_vote<T: KeypairUtil>(voting_keypair: &T, bank: &Bank, slot: u64) {
-        let ix = vote_instruction::vote(&voting_keypair.pubkey(), Vote::new(slot));
+        let ix = vote_instruction::vote(&voting_keypair.pubkey(), vec![Vote::new(slot)]);
         process_instructions(bank, &[voting_keypair], vec![ix]);
     }
 
@@ -158,7 +158,10 @@ pub mod tests {
             0,
             lamports,
         );
-        ixs.push(vote_instruction::vote(&voting_pubkey, Vote::new(slot)));
+        ixs.push(vote_instruction::vote(
+            &voting_pubkey,
+            vec![Vote::new(slot)],
+        ));
         process_instructions(bank, &[from_keypair, voting_keypair], ixs);
     }
 }

programs/vote_api/src/vote_instruction.rs

@@ -20,7 +20,8 @@ pub enum VoteInstruction {
     /// Authorize a voter to send signed votes.
     AuthorizeVoter(Pubkey),
 
-    Vote(Vote),
+    /// A Vote instruction with recent votes
+    Vote(Vec<Vote>),
 }
 
 fn initialize_account(vote_id: &Pubkey, node_id: &Pubkey, commission: u32) -> Instruction {
@@ -54,9 +55,9 @@ pub fn authorize_voter(vote_id: &Pubkey, authorized_voter_id: &Pubkey) -> Instru
     )
 }
 
-pub fn vote(vote_id: &Pubkey, vote: Vote) -> Instruction {
+pub fn vote(vote_id: &Pubkey, recent_votes: Vec<Vote>) -> Instruction {
     let account_metas = vec![AccountMeta::new(*vote_id, true)];
-    Instruction::new(id(), &VoteInstruction::Vote(vote), account_metas)
+    Instruction::new(id(), &VoteInstruction::Vote(recent_votes), account_metas)
 }
 
 pub fn process_instruction(
@@ -144,7 +145,7 @@ mod tests {
         vote_keypair: &Keypair,
         tick_height: u64,
     ) -> Result<()> {
-        let vote_ix = vote_instruction::vote(&vote_keypair.pubkey(), Vote::new(tick_height));
+        let vote_ix = vote_instruction::vote(&vote_keypair.pubkey(), vec![Vote::new(tick_height)]);
         bank_client
             .send_instruction(vote_keypair, vote_ix)
             .map_err(|err| err.unwrap())?;
@@ -195,7 +196,7 @@ mod tests {
         create_vote_account(&bank_client, &mallory_keypair, &vote_id, 100).unwrap();
 
         let mallory_id = mallory_keypair.pubkey();
-        let mut vote_ix = vote_instruction::vote(&vote_id, Vote::new(0));
+        let mut vote_ix = vote_instruction::vote(&vote_id, vec![Vote::new(0)]);
         vote_ix.accounts[0].is_signer = false; // <--- attack!! No signer required.
 
         // Sneak in an instruction so that the transaction is signed but

programs/vote_api/src/vote_state.rs

@@ -117,6 +117,10 @@ impl VoteState {
         }
     }
 
+    pub fn process_votes(&mut self, votes: &[Vote]) {
+        votes.iter().for_each(|v| self.process_vote(v));;
+    }
+
     pub fn process_vote(&mut self, vote: &Vote) {
         // Ignore votes for slots earlier than we already have votes for
         if self
@@ -227,7 +231,7 @@ pub fn initialize_account(
 pub fn process_vote(
     vote_account: &mut KeyedAccount,
     other_signers: &[KeyedAccount],
-    vote: &Vote,
+    votes: &[Vote],
 ) -> Result<(), InstructionError> {
     let mut vote_state: VoteState = vote_account.state()?;
 
@@ -245,7 +249,7 @@ pub fn process_vote(
         return Err(InstructionError::MissingRequiredSignature);
     }
 
-    vote_state.process_vote(vote);
+    vote_state.process_votes(&votes);
     vote_account.set_state(&vote_state)
 }
 
@@ -276,7 +280,7 @@ pub fn vote(
     process_vote(
         &mut KeyedAccount::new(vote_id, true, vote_account),
         &[],
-        vote,
+        &[vote.clone()],
     )?;
     vote_account.state()
 }
@@ -286,6 +290,8 @@ mod tests {
     use super::*;
     use crate::vote_state;
 
+    const MAX_RECENT_VOTES: usize = 16;
+
     #[test]
     fn test_initialize_vote_account() {
         let vote_account_id = Pubkey::new_rand();
@@ -346,7 +352,7 @@ mod tests {
     fn test_vote_signature() {
         let (vote_id, mut vote_account) = create_test_account();
 
-        let vote = Vote::new(1);
+        let vote = vec![Vote::new(1)];
 
         // unsigned
         let res = process_vote(
@@ -392,7 +398,7 @@ mod tests {
         assert_eq!(res, Ok(()));
 
         // not signed by authorized voter
-        let vote = Vote::new(2);
+        let vote = vec![Vote::new(2)];
         let res = process_vote(
             &mut KeyedAccount::new(&vote_id, true, &mut vote_account),
             &[],
@@ -401,7 +407,7 @@ mod tests {
         assert_eq!(res, Err(InstructionError::MissingRequiredSignature));
 
         // signed by authorized voter
-        let vote = Vote::new(2);
+        let vote = vec![Vote::new(2)];
         let res = process_vote(
             &mut KeyedAccount::new(&vote_id, false, &mut vote_account),
             &[KeyedAccount::new(
@@ -571,4 +577,34 @@ mod tests {
             );
         }
     }
+
+    fn recent_votes(vote_state: &VoteState) -> Vec<Vote> {
+        let start = vote_state.votes.len().saturating_sub(MAX_RECENT_VOTES);
+        (start..vote_state.votes.len())
+            .map(|i| Vote::new(vote_state.votes.get(i).unwrap().slot))
+            .collect()
+    }
+
+    /// check that two accounts with different data can be brought to the same state with one vote submission
+    #[test]
+    fn test_process_missed_votes() {
+        let account_a = Pubkey::new_rand();
+        let mut vote_state_a = VoteState::new(&account_a, &Pubkey::new_rand(), 0);
+        let account_b = Pubkey::new_rand();
+        let mut vote_state_b = VoteState::new(&account_b, &Pubkey::new_rand(), 0);
+
+        // process some votes on account a
+        let votes_a: Vec<_> = (0..5).into_iter().map(|i| Vote::new(i)).collect();
+        vote_state_a.process_votes(&votes_a);
+        assert_ne!(recent_votes(&vote_state_a), recent_votes(&vote_state_b));
+
+        // as long as b has missed less than "NUM_RECENT" votes both accounts should be in sync
+        let votes: Vec<_> = (0..MAX_RECENT_VOTES)
+            .into_iter()
+            .map(|i| Vote::new(i as u64))
+            .collect();
+        vote_state_a.process_votes(&votes);
+        vote_state_b.process_votes(&votes);
+        assert_eq!(recent_votes(&vote_state_a), recent_votes(&vote_state_b));
+    }
 }