core: concurrent background transaction sender ecrecover

3 files changed, 113 insertions, 0 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 3eee75df7..bf1bbe6cb 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1005,6 +1005,10 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 // only reason this method exists as a separate one is to make locking cleaner
 // with deferred statements.
 func (bc *BlockChain) insertChain(chain types.Blocks) (int, []interface{}, []*types.Log, error) {
+	// Sanity check that we have something meaningful to import
+	if len(chain) == 0 {
+		return 0, nil, nil, nil
+	}
 	// Do a sanity check that the provided chain is actually ordered and linked
 	for i := 1; i < len(chain); i++ {
 		if chain[i].NumberU64() != chain[i-1].NumberU64()+1 || chain[i].ParentHash() != chain[i-1].Hash() {
@@ -1043,6 +1047,9 @@ func (bc *BlockChain) insertChain(chain types.Blocks) (int, []interface{}, []*ty
 	abort, results := bc.engine.VerifyHeaders(bc, headers, seals)
 	defer close(abort)
 
+	// Start a parallel signature recovery (signer will fluke on fork transition, minimal perf loss)
+	senderCacher.recoverFromBlocks(types.MakeSigner(bc.chainConfig, chain[0].Number()), chain)
+
 	// Iterate over the blocks and insert when the verifier permits
 	for i, block := range chain {
 		// If the chain is terminating, stop processing blocks
diff --git a/core/tx_cacher.go b/core/tx_cacher.go
new file mode 100644
index 000000000..6d989c83d
--- /dev/null
+++ b/core/tx_cacher.go
@@ -0,0 +1,105 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"runtime"
+
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// senderCacher is a concurrent tranaction sender recoverer anc cacher.
+var senderCacher = newTxSenderCacher(runtime.NumCPU())
+
+// txSenderCacherRequest is a request for recovering transaction senders with a
+// specific signature scheme and caching it into the transactions themselves.
+//
+// The inc field defines the number of transactions to skip after each recovery,
+// which is used to feed the same underlying input array to different threads but
+// ensure they process the early transactions fast.
+type txSenderCacherRequest struct {
+	signer types.Signer
+	txs    []*types.Transaction
+	inc    int
+}
+
+// txSenderCacher is a helper structure to concurrently ecrecover transaction
+// senders from digital signatures on background threads.
+type txSenderCacher struct {
+	threads int
+	tasks   chan *txSenderCacherRequest
+}
+
+// newTxSenderCacher creates a new transaction sender background cacher and starts
+// as many procesing goroutines as allowed by the GOMAXPROCS on construction.
+func newTxSenderCacher(threads int) *txSenderCacher {
+	cacher := &txSenderCacher{
+		tasks:   make(chan *txSenderCacherRequest, threads),
+		threads: threads,
+	}
+	for i := 0; i < threads; i++ {
+		go cacher.cache()
+	}
+	return cacher
+}
+
+// cache is an infinite loop, caching transaction senders from various forms of
+// data structures.
+func (cacher *txSenderCacher) cache() {
+	for task := range cacher.tasks {
+		for i := 0; i < len(task.txs); i += task.inc {
+			types.Sender(task.signer, task.txs[i])
+		}
+	}
+}
+
+// recover recovers the senders from a batch of transactions and caches them
+// back into the same data structures. There is no validation being done, nor
+// any reaction to invalid signatures. That is up to calling code later.
+func (cacher *txSenderCacher) recover(signer types.Signer, txs []*types.Transaction) {
+	// If there's nothing to recover, abort
+	if len(txs) == 0 {
+		return
+	}
+	// Ensure we have meaningful task sizes and schedule the recoveries
+	tasks := cacher.threads
+	if len(txs) < tasks*4 {
+		tasks = (len(txs) + 3) / 4
+	}
+	for i := 0; i < tasks; i++ {
+		cacher.tasks <- &txSenderCacherRequest{
+			signer: signer,
+			txs:    txs[i:],
+			inc:    tasks,
+		}
+	}
+}
+
+// recoverFromBlocks recovers the senders from a batch of blocks and caches them
+// back into the same data structures. There is no validation being done, nor
+// any reaction to invalid signatures. That is up to calling code later.
+func (cacher *txSenderCacher) recoverFromBlocks(signer types.Signer, blocks []*types.Block) {
+	count := 0
+	for _, block := range blocks {
+		count += len(block.Transactions())
+	}
+	txs := make([]*types.Transaction, 0, count)
+	for _, block := range blocks {
+		txs = append(txs, block.Transactions()...)
+	}
+	cacher.recover(signer, txs)
+}
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 7393c8286..a0287b68a 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -411,6 +411,7 @@ func (pool *TxPool) reset(oldHead, newHead *types.Header) {
 
 	// Inject any transactions discarded due to reorgs
 	log.Debug("Reinjecting stale transactions", "count", len(reinject))
+	senderCacher.recover(pool.signer, reinject)
 	pool.addTxsLocked(reinject, false)
 
 	// validate the pool of pending transactions, this will remove