Never drop local transactions from different senders.

miner/src/pool/scoring.rs

@@ -30,7 +30,7 @@
 use std::cmp;
 
 use ethereum_types::U256;
-use txpool;
+use txpool::{self, scoring};
 use super::{verifier, PrioritizationStrategy, VerifiedTransaction};
 
 /// Transaction with the same (sender, nonce) can be replaced only if
@@ -75,9 +75,9 @@ impl txpool::Scoring<VerifiedTransaction> for NonceAndGasPrice {
 		old.transaction.nonce.cmp(&other.transaction.nonce)
 	}
 
-	fn choose(&self, old: &VerifiedTransaction, new: &VerifiedTransaction) -> txpool::scoring::Choice {
+	fn choose(&self, old: &VerifiedTransaction, new: &VerifiedTransaction) -> scoring::Choice {
 		if old.transaction.nonce != new.transaction.nonce {
-			return txpool::scoring::Choice::InsertNew
+			return scoring::Choice::InsertNew
 		}
 
 		let old_gp = old.transaction.gas_price;
@@ -86,13 +86,13 @@ impl txpool::Scoring<VerifiedTransaction> for NonceAndGasPrice {
 		let min_required_gp = bump_gas_price(old_gp);
 
 		match min_required_gp.cmp(&new_gp) {
-			cmp::Ordering::Greater => txpool::scoring::Choice::RejectNew,
-			_ => txpool::scoring::Choice::ReplaceOld,
+			cmp::Ordering::Greater => scoring::Choice::RejectNew,
+			_ => scoring::Choice::ReplaceOld,
 		}
 	}
 
-	fn update_scores(&self, txs: &[txpool::Transaction<VerifiedTransaction>], scores: &mut [U256], change: txpool::scoring::Change) {
-		use self::txpool::scoring::Change;
+	fn update_scores(&self, txs: &[txpool::Transaction<VerifiedTransaction>], scores: &mut [U256], change: scoring::Change) {
+		use self::scoring::Change;
 
 		match change {
 			Change::Culled(_) => {},
@@ -122,19 +122,26 @@ impl txpool::Scoring<VerifiedTransaction> for NonceAndGasPrice {
 		}
 	}
 
-	fn should_replace(&self, old: &VerifiedTransaction, new: &VerifiedTransaction) -> bool {
+	fn should_replace(&self, old: &VerifiedTransaction, new: &VerifiedTransaction) -> scoring::Choice {
 		if old.sender == new.sender {
 			// prefer earliest transaction
 			match new.transaction.nonce.cmp(&old.transaction.nonce) {
-				cmp::Ordering::Less => true,
-				cmp::Ordering::Greater => false,
-				cmp::Ordering::Equal => self.choose(old, new) == txpool::scoring::Choice::ReplaceOld,
+				cmp::Ordering::Less => scoring::Choice::ReplaceOld,
+				cmp::Ordering::Greater => scoring::Choice::RejectNew,
+				cmp::Ordering::Equal => self.choose(old, new),
 			}
+		} else if old.priority().is_local() && new.priority().is_local() {
+			// accept local transactions over the limit
+			scoring::Choice::InsertNew
 		} else {
 			let old_score = (old.priority(), old.transaction.gas_price);
 			let new_score = (new.priority(), new.transaction.gas_price);
-			new_score > old_score
-		}
+			if new_score > old_score {
+				scoring::Choice::ReplaceOld
+			} else {
+				scoring::Choice::RejectNew
+			}
+	 	}
 	}
 }
 
@@ -146,6 +153,7 @@ mod tests {
 	use ethkey::{Random, Generator};
 	use pool::tests::tx::{Tx, TxExt};
 	use txpool::Scoring;
+	use txpool::scoring::Choice::*;
 
 	#[test]
 	fn should_replace_same_sender_by_nonce() {
@@ -181,14 +189,14 @@ mod tests {
 			}
 		}).collect::<Vec<_>>();
 
-		assert!(!scoring.should_replace(&txs[0], &txs[1]));
-		assert!(scoring.should_replace(&txs[1], &txs[0]));
+		assert_eq!(scoring.should_replace(&txs[0], &txs[1]), RejectNew);
+		assert_eq!(scoring.should_replace(&txs[1], &txs[0]), ReplaceOld);
 
-		assert!(!scoring.should_replace(&txs[1], &txs[2]));
-		assert!(!scoring.should_replace(&txs[2], &txs[1]));
+		assert_eq!(scoring.should_replace(&txs[1], &txs[2]), RejectNew);
+		assert_eq!(scoring.should_replace(&txs[2], &txs[1]), RejectNew);
 
-		assert!(scoring.should_replace(&txs[1], &txs[3]));
-		assert!(!scoring.should_replace(&txs[3], &txs[1]));
+		assert_eq!(scoring.should_replace(&txs[1], &txs[3]), ReplaceOld);
+		assert_eq!(scoring.should_replace(&txs[3], &txs[1]), RejectNew);
 	}
 
 	#[test]
@@ -246,14 +254,14 @@ mod tests {
 			}
 		};
 
-		assert!(scoring.should_replace(&tx_regular_low_gas, &tx_regular_high_gas));
-		assert!(!scoring.should_replace(&tx_regular_high_gas, &tx_regular_low_gas));
+		assert_eq!(scoring.should_replace(&tx_regular_low_gas, &tx_regular_high_gas), ReplaceOld);
+		assert_eq!(scoring.should_replace(&tx_regular_high_gas, &tx_regular_low_gas), RejectNew);
 
-		assert!(scoring.should_replace(&tx_regular_high_gas, &tx_local_low_gas));
-		assert!(!scoring.should_replace(&tx_local_low_gas, &tx_regular_high_gas));
+		assert_eq!(scoring.should_replace(&tx_regular_high_gas, &tx_local_low_gas), ReplaceOld);
+		assert_eq!(scoring.should_replace(&tx_local_low_gas, &tx_regular_high_gas), RejectNew);
 
-		assert!(scoring.should_replace(&tx_local_low_gas, &tx_local_high_gas));
-		assert!(!scoring.should_replace(&tx_local_high_gas, &tx_regular_low_gas));
+		assert_eq!(scoring.should_replace(&tx_local_low_gas, &tx_local_high_gas), InsertNew);
+		assert_eq!(scoring.should_replace(&tx_local_high_gas, &tx_regular_low_gas), RejectNew);
 	}
 
 	#[test]
@@ -277,35 +285,35 @@ mod tests {
 
 		// No update required
 		let mut scores = initial_scores.clone();
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::Culled(0));
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::Culled(1));
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::Culled(2));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::Culled(0));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::Culled(1));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::Culled(2));
 		assert_eq!(scores, initial_scores);
 		let mut scores = initial_scores.clone();
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::RemovedAt(0));
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::RemovedAt(1));
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::RemovedAt(2));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::RemovedAt(0));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::RemovedAt(1));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::RemovedAt(2));
 		assert_eq!(scores, initial_scores);
 
 		// Compute score at given index
 		let mut scores = initial_scores.clone();
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::InsertedAt(0));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::InsertedAt(0));
 		assert_eq!(scores, vec![32768.into(), 0.into(), 0.into()]);
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::InsertedAt(1));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::InsertedAt(1));
 		assert_eq!(scores, vec![32768.into(), 1024.into(), 0.into()]);
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::InsertedAt(2));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::InsertedAt(2));
 		assert_eq!(scores, vec![32768.into(), 1024.into(), 1.into()]);
 
 		let mut scores = initial_scores.clone();
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::ReplacedAt(0));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::ReplacedAt(0));
 		assert_eq!(scores, vec![32768.into(), 0.into(), 0.into()]);
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::ReplacedAt(1));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::ReplacedAt(1));
 		assert_eq!(scores, vec![32768.into(), 1024.into(), 0.into()]);
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::ReplacedAt(2));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::ReplacedAt(2));
 		assert_eq!(scores, vec![32768.into(), 1024.into(), 1.into()]);
 
 		// Check penalization
-		scoring.update_scores(&transactions, &mut *scores, txpool::scoring::Change::Event(()));
+		scoring.update_scores(&transactions, &mut *scores, scoring::Change::Event(()));
 		assert_eq!(scores, vec![32768.into(), 128.into(), 0.into()]);
 	}
 }

miner/src/pool/tests/mod.rs

@@ -41,7 +41,6 @@ fn new_queue() -> TransactionQueue {
 		PrioritizationStrategy::GasPriceOnly,
 	)
 }
-
 #[test]
 fn should_return_correct_nonces_when_dropped_because_of_limit() {
 	// given
@@ -63,8 +62,8 @@ fn should_return_correct_nonces_when_dropped_because_of_limit() {
 	let nonce = tx1.nonce;
 
 	// when
-	let r1= txq.import(TestClient::new(), vec![tx1].local());
-	let r2= txq.import(TestClient::new(), vec![tx2].local());
+	let r1 = txq.import(TestClient::new(), vec![tx1].retracted());
+	let r2 = txq.import(TestClient::new(), vec![tx2].retracted());
 	assert_eq!(r1, vec![Ok(())]);
 	assert_eq!(r2, vec![Err(transaction::Error::LimitReached)]);
 	assert_eq!(txq.status().status.transaction_count, 1);
@@ -77,17 +76,68 @@ fn should_return_correct_nonces_when_dropped_because_of_limit() {
 	let tx2 = Tx::gas_price(2).signed();
 	let tx3 = Tx::gas_price(1).signed();
 	let tx4 = Tx::gas_price(3).signed();
-	let res = txq.import(TestClient::new(), vec![tx1, tx2].local());
-	let res2 = txq.import(TestClient::new(), vec![tx3, tx4].local());
+	let res = txq.import(TestClient::new(), vec![tx1, tx2].retracted());
+	let res2 = txq.import(TestClient::new(), vec![tx3, tx4].retracted());
 
 	// then
 	assert_eq!(res, vec![Ok(()), Ok(())]);
-	assert_eq!(res2, vec![Err(transaction::Error::LimitReached), Ok(())]);
+	assert_eq!(res2, vec![
+			   // The error here indicates reaching the limit
+			   // and minimal effective gas price taken into account.
+			   Err(transaction::Error::InsufficientGasPrice { minimal: 2.into(), got: 1.into() }),
+			   Ok(())
+	]);
 	assert_eq!(txq.status().status.transaction_count, 3);
 	// First inserted transacton got dropped because of limit
 	assert_eq!(txq.next_nonce(TestClient::new(), &sender), None);
 }
 
+#[test]
+fn should_never_drop_local_transactions_from_different_senders() {
+	// given
+	let txq = TransactionQueue::new(
+		txpool::Options {
+			max_count: 3,
+			max_per_sender: 1,
+			max_mem_usage: 50
+		},
+		verifier::Options {
+			minimal_gas_price: 1.into(),
+			block_gas_limit: 1_000_000.into(),
+			tx_gas_limit: 1_000_000.into(),
+		},
+		PrioritizationStrategy::GasPriceOnly,
+	);
+	let (tx1, tx2) = Tx::gas_price(2).signed_pair();
+	let sender = tx1.sender();
+	let nonce = tx1.nonce;
+
+	// when
+	let r1 = txq.import(TestClient::new(), vec![tx1].local());
+	let r2 = txq.import(TestClient::new(), vec![tx2].local());
+	assert_eq!(r1, vec![Ok(())]);
+	// max-per-sender is reached, that's ok.
+	assert_eq!(r2, vec![Err(transaction::Error::LimitReached)]);
+	assert_eq!(txq.status().status.transaction_count, 1);
+
+	// then
+	assert_eq!(txq.next_nonce(TestClient::new(), &sender), Some(nonce + 1.into()));
+
+	// when
+	let tx1 = Tx::gas_price(2).signed();
+	let tx2 = Tx::gas_price(2).signed();
+	let tx3 = Tx::gas_price(1).signed();
+	let tx4 = Tx::gas_price(3).signed();
+	let res = txq.import(TestClient::new(), vec![tx1, tx2].local());
+	let res2 = txq.import(TestClient::new(), vec![tx3, tx4].local());
+
+	// then
+	assert_eq!(res, vec![Ok(()), Ok(())]);
+	assert_eq!(res2, vec![Ok(()), Ok(())]);
+	assert_eq!(txq.status().status.transaction_count, 5);
+	assert_eq!(txq.next_nonce(TestClient::new(), &sender), Some(nonce + 1.into()));
+}
+
 #[test]
 fn should_handle_same_transaction_imported_twice_with_different_state_nonces() {
 	// given

transaction-pool/src/pool.rs

@@ -22,7 +22,7 @@ use error;
 use listener::{Listener, NoopListener};
 use options::Options;
 use ready::{Ready, Readiness};
-use scoring::{Scoring, ScoreWithRef};
+use scoring::{self, Scoring, ScoreWithRef};
 use status::{LightStatus, Status};
 use transactions::{AddResult, Transactions};
 
@@ -139,7 +139,7 @@ impl<T, S, L> Pool<T, S, L> where
 		ensure!(!self.by_hash.contains_key(transaction.hash()), error::ErrorKind::AlreadyImported(format!("{:?}", transaction.hash())));
 
 		self.insertion_id += 1;
-		let mut transaction = Transaction {
+		let transaction = Transaction {
 			insertion_id: self.insertion_id,
 			transaction: Arc::new(transaction),
 		};
@@ -148,27 +148,32 @@ impl<T, S, L> Pool<T, S, L> where
 		// Avoid using should_replace, but rather use scoring for that.
 		{
 			let remove_worst = |s: &mut Self, transaction| {
-				match s.remove_worst(&transaction) {
+				match s.remove_worst(transaction) {
 					Err(err) => {
-						s.listener.rejected(&transaction, err.kind());
+						s.listener.rejected(transaction, err.kind());
 						Err(err)
 					},
-					Ok(removed) => {
-						s.listener.dropped(&removed, Some(&transaction));
+					Ok(None) => Ok(false),
+					Ok(Some(removed)) => {
+						s.listener.dropped(&removed, Some(transaction));
 						s.finalize_remove(removed.hash());
-						Ok(transaction)
+						Ok(true)
 					},
 				}
 			};
 
 			while self.by_hash.len() + 1 > self.options.max_count {
 				trace!("Count limit reached: {} > {}", self.by_hash.len() + 1, self.options.max_count);
-				transaction = remove_worst(self, transaction)?;
+				if !remove_worst(self, &transaction)? {
+					break;
+				}
 			}
 
 			while self.mem_usage + mem_usage > self.options.max_mem_usage {
 				trace!("Mem limit reached: {} > {}", self.mem_usage + mem_usage, self.options.max_mem_usage);
-				transaction = remove_worst(self, transaction)?;
+				if !remove_worst(self, &transaction)? {
+					break;
+				}
 			}
 		}
 
@@ -273,28 +278,38 @@ impl<T, S, L> Pool<T, S, L> where
 	}
 
 	/// Attempts to remove the worst transaction from the pool if it's worse than the given one.
-	fn remove_worst(&mut self, transaction: &Transaction<T>) -> error::Result<Transaction<T>> {
+	///
+	/// Returns `None` in case we couldn't decide if the transaction should replace the worst transaction or not.
+	/// In such case we will accept the transaction even though it is going to exceed the limit.
+	fn remove_worst(&mut self, transaction: &Transaction<T>) -> error::Result<Option<Transaction<T>>> {
 		let to_remove = match self.worst_transactions.iter().next_back() {
 			// No elements to remove? and the pool is still full?
 			None => {
 				warn!("The pool is full but there are no transactions to remove.");
 				return Err(error::ErrorKind::TooCheapToEnter(format!("{:?}", transaction.hash()), "unknown".into()).into());
 			},
-			Some(old) => if self.scoring.should_replace(&old.transaction, transaction) {
+			Some(old) => match self.scoring.should_replace(&old.transaction, transaction) {
+				// We can't decide which of them should be removed, so accept both.
+				scoring::Choice::InsertNew => None,
 				// New transaction is better than the worst one so we can replace it.
-				old.clone()
-			} else {
+				scoring::Choice::ReplaceOld => Some(old.clone()),
 				// otherwise fail
-				return Err(error::ErrorKind::TooCheapToEnter(format!("{:?}", transaction.hash()), format!("{:?}", old.score)).into())
+				scoring::Choice::RejectNew => {
+					return Err(error::ErrorKind::TooCheapToEnter(format!("{:?}", transaction.hash()), format!("{:?}", old.score)).into())
+				},
 			},
 		};
 
-		// Remove from transaction set
-		self.remove_from_set(to_remove.transaction.sender(), |set, scoring| {
-			set.remove(&to_remove.transaction, scoring)
-		});
+		if let Some(to_remove) = to_remove {
+			// Remove from transaction set
+			self.remove_from_set(to_remove.transaction.sender(), |set, scoring| {
+				set.remove(&to_remove.transaction, scoring)
+			});
 
-		Ok(to_remove.transaction)
+			Ok(Some(to_remove.transaction))
+		} else {
+			Ok(None)
+		}
 	}
 
 	/// Removes transaction from sender's transaction `HashMap`.

transaction-pool/src/scoring.rs

@@ -99,7 +99,9 @@ pub trait Scoring<T>: fmt::Debug {
 	fn update_scores(&self, txs: &[Transaction<T>], scores: &mut [Self::Score], change: Change<Self::Event>);
 
 	/// Decides if `new` should push out `old` transaction from the pool.
-	fn should_replace(&self, old: &T, new: &T) -> bool;
+	///
+	/// NOTE returning `InsertNew` here can lead to some transactions being accepted above pool limits.
+	fn should_replace(&self, old: &T, new: &T) -> Choice;
 }
 
 /// A score with a reference to the transaction.