[R4R]Prefetch state data on mining process

core/state_prefetcher.go

@@ -27,6 +27,7 @@ import (
 )
 
 const prefetchThread = 2
+const checkInterval = 10
 
 // statePrefetcher is a basic Prefetcher, which blindly executes a block on top
 // of an arbitrary state with the goal of prefetching potentially useful state
@@ -88,6 +89,63 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 	}
 }
 
+// PrefetchMining processes the state changes according to the Ethereum rules by running
+// the transaction messages using the statedb, but any changes are discarded. The
+// only goal is to pre-cache transaction signatures and snapshot clean state. Only used for mining stage
+func (p *statePrefetcher) PrefetchMining(txs *types.TransactionsByPriceAndNonce, header *types.Header, gasLimit uint64, statedb *state.StateDB, cfg vm.Config, interruptCh <-chan struct{}, txCurr **types.Transaction) {
+	var signer = types.MakeSigner(p.config, header.Number)
+
+	txCh := make(chan *types.Transaction, 2*prefetchThread)
+	for i := 0; i < prefetchThread; i++ {
+		go func(startCh <-chan *types.Transaction, stopCh <-chan struct{}) {
+			idx := 0
+			newStatedb := statedb.Copy()
+			gaspool := new(GasPool).AddGas(gasLimit)
+			blockContext := NewEVMBlockContext(header, p.bc, nil)
+			evm := vm.NewEVM(blockContext, vm.TxContext{}, statedb, p.config, cfg)
+			// Iterate over and process the individual transactions
+			for {
+				select {
+				case tx := <-startCh:
+					// Convert the transaction into an executable message and pre-cache its sender
+					msg, err := tx.AsMessageNoNonceCheck(signer)
+					if err != nil {
+						return // Also invalid block, bail out
+					}
+					idx++
+					newStatedb.Prepare(tx.Hash(), header.Hash(), idx)
+					precacheTransaction(msg, p.config, gaspool, newStatedb, header, evm)
+					gaspool = new(GasPool).AddGas(gasLimit)
+				case <-stopCh:
+					return
+				}
+			}
+		}(txCh, interruptCh)
+	}
+	go func(txset *types.TransactionsByPriceAndNonce) {
+		count := 0
+		for {
+			tx := txset.Peek()
+			if tx == nil {
+				return
+			}
+			select {
+			case <-interruptCh:
+				return
+			default:
+			}
+			if count++; count%checkInterval == 0 {
+				if *txCurr == nil {
+					return
+				}
+				txset.Forward(*txCurr)
+			}
+			txCh <- tx
+			txset.Shift()
+		}
+	}(txs)
+}
+
 // precacheTransaction attempts to apply a transaction to the given state database
 // and uses the input parameters for its environment. The goal is not to execute
 // the transaction successfully, rather to warm up touched data slots.

core/types.go

@@ -40,6 +40,8 @@ type Prefetcher interface {
 	// the transaction messages using the statedb, but any changes are discarded. The
 	// only goal is to pre-cache transaction signatures and state trie nodes.
 	Prefetch(block *types.Block, statedb *state.StateDB, cfg vm.Config, interrupt *uint32)
+	// PrefetchMining used for pre-caching transaction signatures and state trie nodes. Only used for mining stage.
+	PrefetchMining(txs *types.TransactionsByPriceAndNonce, header *types.Header, gasLimit uint64, statedb *state.StateDB, cfg vm.Config, interruptCh <-chan struct{}, txCurr **types.Transaction)
 }
 
 // Processor is an interface for processing blocks using a given initial state.

core/types/transaction.go

@@ -458,6 +458,21 @@ func NewTransactionsByPriceAndNonce(signer Signer, txs map[common.Address]Transa
 	}
 }
 
+// Copy copys a new TransactionsPriceAndNonce with the same *transaction
+func (t *TransactionsByPriceAndNonce) Copy() *TransactionsByPriceAndNonce {
+	heads := make([]*Transaction, len(t.heads))
+	copy(heads, t.heads)
+	txs := make(map[common.Address]Transactions, len(t.txs))
+	for acc, txsTmp := range t.txs {
+		txs[acc] = txsTmp
+	}
+	return &TransactionsByPriceAndNonce{
+		heads:  heads,
+		txs:    txs,
+		signer: t.signer,
+	}
+}
+
 // Peek returns the next transaction by price.
 func (t *TransactionsByPriceAndNonce) Peek() *Transaction {
 	if len(t.heads) == 0 {
@@ -488,6 +503,44 @@ func (t *TransactionsByPriceAndNonce) CurrentSize() int {
 	return len(t.heads)
 }
 
+//Forward moves current transaction to be the one which is one index after tx
+func (t *TransactionsByPriceAndNonce) Forward(tx *Transaction) {
+	if tx == nil {
+		t.heads = t.heads[0:0]
+		return
+	}
+	//check whether target tx exists in t.heads
+	for _, head := range t.heads {
+		if tx == head {
+			//shift t to the position one after tx
+			txTmp := t.Peek()
+			for txTmp != tx {
+				t.Shift()
+				txTmp = t.Peek()
+			}
+			t.Shift()
+			return
+		}
+	}
+	//get the sender address of tx
+	acc, _ := Sender(t.signer, tx)
+	//check whether target tx exists in t.txs
+	if txs, ok := t.txs[acc]; ok {
+		for _, txTmp := range txs {
+			//found the same pointer in t.txs as tx and then shift t to the position one after tx
+			if txTmp == tx {
+				txTmp = t.Peek()
+				for txTmp != tx {
+					t.Shift()
+					txTmp = t.Peek()
+				}
+				t.Shift()
+				return
+			}
+		}
+	}
+}
+
 // Message is a fully derived transaction and implements core.Message
 //
 // NOTE: In a future PR this will be removed.
@@ -535,6 +588,15 @@ func (tx *Transaction) AsMessage(s Signer) (Message, error) {
 	return msg, err
 }
 
+// AsMessageNoNonceCheck returns the transaction with checkNonce field set to be false.
+func (tx *Transaction) AsMessageNoNonceCheck(s Signer) (Message, error) {
+	msg, err := tx.AsMessage(s)
+	if err == nil {
+		msg.checkNonce = false
+	}
+	return msg, err
+}
+
 func (m Message) From() common.Address   { return m.from }
 func (m Message) To() *common.Address    { return m.to }
 func (m Message) GasPrice() *big.Int     { return m.gasPrice }

core/types/transaction_test.go

@@ -358,6 +358,75 @@ func TestTransactionTimeSort(t *testing.T) {
 	}
 }
 
+func TestTransactionForward(t *testing.T) {
+	// Generate a batch of accounts to start with
+	keys := make([]*ecdsa.PrivateKey, 5)
+	for i := 0; i < len(keys); i++ {
+		keys[i], _ = crypto.GenerateKey()
+	}
+	signer := HomesteadSigner{}
+
+	// Generate a batch of transactions with overlapping prices, but different creation times
+	groups := map[common.Address]Transactions{}
+	for start, key := range keys {
+		addr := crypto.PubkeyToAddress(key.PublicKey)
+
+		tx, _ := SignTx(NewTransaction(0, common.Address{}, big.NewInt(100), 100, big.NewInt(1), nil), signer, key)
+		tx2, _ := SignTx(NewTransaction(1, common.Address{}, big.NewInt(100), 100, big.NewInt(1), nil), signer, key)
+
+		tx.time = time.Unix(0, int64(len(keys)-start))
+		tx2.time = time.Unix(1, int64(len(keys)-start))
+
+		groups[addr] = append(groups[addr], tx)
+		groups[addr] = append(groups[addr], tx2)
+
+	}
+	// Sort the transactions
+	txset := NewTransactionsByPriceAndNonce(signer, groups)
+	txsetCpy := txset.Copy()
+
+	txs := Transactions{}
+	for tx := txsetCpy.Peek(); tx != nil; tx = txsetCpy.Peek() {
+		txs = append(txs, tx)
+		txsetCpy.Shift()
+	}
+
+	tmp := txset.Copy()
+	for j := 0; j < 10; j++ {
+		txset = tmp.Copy()
+		txsetCpy = tmp.Copy()
+		i := 0
+		for ; i < j; i++ {
+			txset.Shift()
+		}
+		tx := txset.Peek()
+		txsetCpy.Forward(tx)
+		txCpy := txsetCpy.Peek()
+		if txCpy == nil {
+			if tx == nil {
+				continue
+			}
+			txset.Shift()
+			if txset.Peek() != nil {
+				t.Errorf("forward got an incorrect result, got %v, want %v", txCpy, tx)
+			} else {
+				continue
+			}
+		}
+		txset.Shift()
+		for ; i < len(txs)-1; i++ {
+			tx = txset.Peek()
+			txCpy = txsetCpy.Peek()
+			if txCpy != tx {
+				t.Errorf("forward got an incorrect result, got %v, want %v", txCpy, tx)
+			}
+			txsetCpy.Shift()
+			txset.Shift()
+		}
+
+	}
+}
+
 // TestTransactionCoding tests serializing/de-serializing to/from rlp and JSON.
 func TestTransactionCoding(t *testing.T) {
 	key, err := crypto.GenerateKey()

miner/worker.go

@@ -130,6 +130,7 @@ type intervalAdjust struct {
 // worker is the main object which takes care of submitting new work to consensus engine
 // and gathering the sealing result.
 type worker struct {
+	prefetcher  core.Prefetcher
 	config      *Config
 	chainConfig *params.ChainConfig
 	engine      consensus.Engine
@@ -196,6 +197,7 @@ type worker struct {
 
 func newWorker(config *Config, chainConfig *params.ChainConfig, engine consensus.Engine, eth Backend, mux *event.TypeMux, isLocalBlock func(*types.Block) bool, init bool) *worker {
 	worker := &worker{
+		prefetcher:         core.NewStatePrefetcher(chainConfig, eth.BlockChain(), engine),
 		config:             config,
 		chainConfig:        chainConfig,
 		engine:             engine,
@@ -778,6 +780,14 @@ func (w *worker) commitTransactions(txs *types.TransactionsByPriceAndNonce, coin
 	}
 	bloomProcessors := core.NewAsyncReceiptBloomGenerator(processorCapacity)
 
+	interruptCh := make(chan struct{})
+	defer close(interruptCh)
+	tx := &types.Transaction{}
+	txCurr := &tx
+	//prefetch txs from all pending txs
+	txsPrefetch := txs.Copy()
+	w.prefetcher.PrefetchMining(txsPrefetch, w.current.header, w.current.gasPool.Gas(), w.current.state.Copy(), *w.chain.GetVMConfig(), interruptCh, txCurr)
+
 LOOP:
 	for {
 		// In the following three cases, we will interrupt the execution of the transaction.
@@ -814,7 +824,7 @@ LOOP:
 			}
 		}
 		// Retrieve the next transaction and abort if all done
-		tx := txs.Peek()
+		tx = txs.Peek()
 		if tx == nil {
 			break
 		}