core/txpool, eth/catalyst: ensure gas tip retains current value upon rollback (#30495)

Here we move the method that drops all transactions by temporarily increasing the fee
into the TxPool itself. It's better to have it there because we can set it back to the
configured value afterwards. This resolves a TODO in the simulated backend.

core/txpool/blobpool/blobpool.go

@@ -1013,21 +1013,10 @@ func (p *BlobPool) reinject(addr common.Address, txhash common.Hash) error {
 	return nil
 }
 
-// SetGasTip implements txpool.SubPool, allowing the blob pool's gas requirements
+func (p *BlobPool) flushTransactionsBelowTip(tip *uint256.Int) {
-// to be kept in sync with the main transaction pool's gas requirements.
-func (p *BlobPool) SetGasTip(tip *big.Int) {
-	p.lock.Lock()
-	defer p.lock.Unlock()
-
-	// Store the new minimum gas tip
-	old := p.gasTip
-	p.gasTip = uint256.MustFromBig(tip)
-
-	// If the min miner fee increased, remove transactions below the new threshold
-	if old == nil || p.gasTip.Cmp(old) > 0 {
 	for addr, txs := range p.index {
 		for i, tx := range txs {
-				if tx.execTipCap.Cmp(p.gasTip) < 0 {
+			if tx.execTipCap.Cmp(tip) < 0 {
 				// Drop the offending transaction
 				var (
 					ids    = []uint64{tx.id}
@@ -1072,12 +1061,34 @@ func (p *BlobPool) SetGasTip(tip *big.Int) {
 			}
 		}
 	}
+}
+
+// SetGasTip implements txpool.SubPool, allowing the blob pool's gas requirements
+// to be kept in sync with the main transaction pool's gas requirements.
+func (p *BlobPool) SetGasTip(tip *big.Int) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	// Store the new minimum gas tip
+	old := p.gasTip
+	p.gasTip = uint256.MustFromBig(tip)
+
+	// If the min miner fee increased, remove transactions below the new threshold
+	if old == nil || p.gasTip.Cmp(old) > 0 {
+		p.flushTransactionsBelowTip(p.gasTip)
 	}
 	log.Debug("Blobpool tip threshold updated", "tip", tip)
 	pooltipGauge.Update(tip.Int64())
 	p.updateStorageMetrics()
 }
 
+func (p *BlobPool) FlushAllTransactions() {
+	maxUint256 := uint256.MustFromBig(new(big.Int).Sub(new(big.Int).Lsh(common.Big1, 256), common.Big1))
+	p.lock.Lock()
+	defer p.lock.Unlock()
+	p.flushTransactionsBelowTip(maxUint256)
+}
+
 // validateTx checks whether a transaction is valid according to the consensus
 // rules and adheres to some heuristic limits of the local node (price and size).
 func (p *BlobPool) validateTx(tx *types.Transaction) error {

core/txpool/legacypool/legacypool.go

@@ -429,6 +429,15 @@ func (pool *LegacyPool) SubscribeTransactions(ch chan<- core.NewTxsEvent, reorgs
 	return pool.txFeed.Subscribe(ch)
 }
 
+func (pool *LegacyPool) flushTransactionsBelowTip(tip *big.Int) {
+	// pool.priced is sorted by GasFeeCap, so we have to iterate through pool.all instead
+	drop := pool.all.RemotesBelowTip(tip)
+	for _, tx := range drop {
+		pool.removeTx(tx.Hash(), false, true)
+	}
+	pool.priced.Removed(len(drop))
+}
+
 // SetGasTip updates the minimum gas tip required by the transaction pool for a
 // new transaction, and drops all transactions below this threshold.
 func (pool *LegacyPool) SetGasTip(tip *big.Int) {
@@ -442,16 +451,18 @@ func (pool *LegacyPool) SetGasTip(tip *big.Int) {
 	pool.gasTip.Store(newTip)
 	// If the min miner fee increased, remove transactions below the new threshold
 	if newTip.Cmp(old) > 0 {
-		// pool.priced is sorted by GasFeeCap, so we have to iterate through pool.all instead
+		pool.flushTransactionsBelowTip(tip)
-		drop := pool.all.RemotesBelowTip(tip)
-		for _, tx := range drop {
-			pool.removeTx(tx.Hash(), false, true)
-		}
-		pool.priced.Removed(len(drop))
 	}
 	log.Info("Legacy pool tip threshold updated", "tip", newTip)
 }
 
+func (pool *LegacyPool) FlushAllTransactions() {
+	maxUint256 := new(big.Int).Sub(new(big.Int).Lsh(common.Big1, 256), common.Big1)
+	pool.mu.Lock()
+	defer pool.mu.Unlock()
+	pool.flushTransactionsBelowTip(maxUint256)
+}
+
 // Nonce returns the next nonce of an account, with all transactions executable
 // by the pool already applied on top.
 func (pool *LegacyPool) Nonce(addr common.Address) uint64 {

core/txpool/subpool.go

@@ -116,6 +116,9 @@ type SubPool interface {
 	// transaction, and drops all transactions below this threshold.
 	SetGasTip(tip *big.Int)
 
+	// FlushAllTransactions drops all transactions in the pool.
+	FlushAllTransactions()
+
 	// Has returns an indicator whether subpool has a transaction cached with the
 	// given hash.
 	Has(hash common.Hash) bool

core/txpool/txpool.go

@@ -104,6 +104,13 @@ func New(gasTip uint64, chain BlockChain, subpools []SubPool) (*TxPool, error) {
 	return pool, nil
 }
 
+// FlushAllTransactions removes all transactions from all subpools
+func (p *TxPool) FlushAllTransactions() {
+	for _, subpool := range p.subpools {
+		subpool.FlushAllTransactions()
+	}
+}
+
 // reserver is a method to create an address reservation callback to exclusively
 // assign/deassign addresses to/from subpools. This can ensure that at any point
 // in time, only a single subpool is able to manage an account, avoiding cross

eth/catalyst/simulated_beacon.go

@@ -21,7 +21,6 @@ import (
 	"crypto/sha256"
 	"errors"
 	"fmt"
-	"math/big"
 	"sync"
 	"time"
 
@@ -34,7 +33,6 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/node"
-	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
@@ -286,12 +284,7 @@ func (c *SimulatedBeacon) Commit() common.Hash {
 
 // Rollback un-sends previously added transactions.
 func (c *SimulatedBeacon) Rollback() {
-	// Flush all transactions from the transaction pools
+	c.eth.TxPool().FlushAllTransactions()
-	maxUint256 := new(big.Int).Sub(new(big.Int).Lsh(common.Big1, 256), common.Big1)
-	c.eth.TxPool().SetGasTip(maxUint256)
-	// Set the gas tip back to accept new transactions
-	// TODO (Marius van der Wijden): set gas tip to parameter passed by config
-	c.eth.TxPool().SetGasTip(big.NewInt(params.GWei))
 }
 
 // Fork sets the head to the provided hash.