From 0228fb57cd58147ab2c3914520c7805e25a8a1c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Wed, 16 Mar 2016 11:20:02 +0200
Subject: [PATCH] eth, miner: fetch pending block/state in on go (data race)

---
 eth/api.go      |  6 ++++--
 miner/miner.go  |  9 +++------
 miner/worker.go | 12 +++---------
 3 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/eth/api.go b/eth/api.go
index 487d24ae7..c16c3d142 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -56,7 +56,8 @@ const defaultGas = uint64(90000)
 func blockByNumber(m *miner.Miner, bc *core.BlockChain, blockNr rpc.BlockNumber) *types.Block {
 	// Pending block is only known by the miner
 	if blockNr == rpc.PendingBlockNumber {
-		return m.PendingBlock()
+		block, _ := m.Pending()
+		return block
 	}
 	// Otherwise resolve and return the block
 	if blockNr == rpc.LatestBlockNumber {
@@ -72,7 +73,8 @@ func blockByNumber(m *miner.Miner, bc *core.BlockChain, blockNr rpc.BlockNumber)
 func stateAndBlockByNumber(m *miner.Miner, bc *core.BlockChain, blockNr rpc.BlockNumber, chainDb ethdb.Database) (*state.StateDB, *types.Block, error) {
 	// Pending state is only known by the miner
 	if blockNr == rpc.PendingBlockNumber {
-		return m.PendingState(), m.PendingBlock(), nil
+		block, state := m.Pending()
+		return state, block, nil
 	}
 	// Otherwise resolve the block number and return its state
 	block := blockByNumber(m, bc, blockNr)
diff --git a/miner/miner.go b/miner/miner.go
index 6d4a84f1a..e52cefaab 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -164,12 +164,9 @@ func (self *Miner) SetExtra(extra []byte) error {
 	return nil
 }
 
-func (self *Miner) PendingState() *state.StateDB {
-	return self.worker.pendingState()
-}
-
-func (self *Miner) PendingBlock() *types.Block {
-	return self.worker.pendingBlock()
+// Pending returns the currently pending block and associated state.
+func (self *Miner) Pending() (*types.Block, *state.StateDB) {
+	return self.worker.pending()
 }
 
 func (self *Miner) SetEtherbase(addr common.Address) {
diff --git a/miner/worker.go b/miner/worker.go
index f3e95cb5f..108b2d6b5 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -152,13 +152,7 @@ func (self *worker) setEtherbase(addr common.Address) {
 	self.coinbase = addr
 }
 
-func (self *worker) pendingState() *state.StateDB {
-	self.currentMu.Lock()
-	defer self.currentMu.Unlock()
-	return self.current.state
-}
-
-func (self *worker) pendingBlock() *types.Block {
+func (self *worker) pending() (*types.Block, *state.StateDB) {
 	self.currentMu.Lock()
 	defer self.currentMu.Unlock()
 
@@ -168,9 +162,9 @@ func (self *worker) pendingBlock() *types.Block {
 			self.current.txs,
 			nil,
 			self.current.receipts,
-		)
+		), self.current.state
 	}
-	return self.current.Block
+	return self.current.Block, self.current.state
 }
 
 func (self *worker) start() {