miner: provide coinbase when starting the miner

This avoids having to query the coinbase when creating the miner, which
in turn eliminates the dreaded startup error when no accounts are set
up. Later, this will also allow us to simply restart the miner when the
user picks a different coinbase.

This causes a lot of changes in other packages. These are included in
this commit because they're impossible to separate.

8 files changed, 74 insertions, 87 deletions

diff --git a/cmd/ethereum/js.go b/cmd/ethereum/js.go
index 5432fb9b1..3b98b588e 100644
--- a/cmd/ethereum/js.go
+++ b/cmd/ethereum/js.go
@@ -249,12 +249,14 @@ func (self *jsre) dump(call otto.FunctionCall) otto.Value {
 }
 
 func (self *jsre) stopMining(call otto.FunctionCall) otto.Value {
-	self.xeth.Miner().Stop()
+	self.ethereum.StopMining()
 	return otto.TrueValue()
 }
 
 func (self *jsre) startMining(call otto.FunctionCall) otto.Value {
-	self.xeth.Miner().Start()
+	if err := self.ethereum.StartMining(); err != nil {
+		return otto.FalseValue()
+	}
 	return otto.TrueValue()
 }
 
diff --git a/cmd/ethereum/main.go b/cmd/ethereum/main.go
index 73c67bdc9..0d239f7b4 100644
--- a/cmd/ethereum/main.go
+++ b/cmd/ethereum/main.go
@@ -214,7 +214,7 @@ func startEth(ctx *cli.Context, eth *eth.Ethereum) {
 		utils.StartRPC(eth, ctx)
 	}
 	if ctx.GlobalBool(utils.MiningEnabledFlag.Name) {
-		eth.Miner().Start()
+		eth.StartMining()
 	}
 }
 
diff --git a/cmd/mist/assets/qml/views/miner.qml b/cmd/mist/assets/qml/views/miner.qml
index 4025ff485..ff2bf85ca 100644
--- a/cmd/mist/assets/qml/views/miner.qml
+++ b/cmd/mist/assets/qml/views/miner.qml
@@ -55,8 +55,8 @@ Rectangle {
 					Button {
 						text: "Start"
 						onClicked: {
-							eth.setGasPrice(minGasPrice.text || "10000000000000");
-							eth.setExtra(blockExtra.text)
+							// eth.setGasPrice(minGasPrice.text || "10000000000000");
+							// eth.setExtra(blockExtra.text)
 							if (eth.toggleMining()) {
 								this.text = "Stop";
 							} else {
@@ -65,35 +65,35 @@ Rectangle {
 						}
 					}
 
-					Rectangle {
-						id: minGasPriceRect
-						anchors.top: parent.top
-						anchors.topMargin: 2
-						width: 200
-						TextField {
-							id: minGasPrice
-							placeholderText: "Min Gas: 10000000000000"
-							width: 200
-							validator: RegExpValidator { regExp: /\d*/ }
-						}
-					}
+					// Rectangle {
+					// 	id: minGasPriceRect
+					// 	anchors.top: parent.top
+					// 	anchors.topMargin: 2
+					// 	width: 200
+					// 	TextField {
+					// 		id: minGasPrice
+					// 		placeholderText: "Min Gas: 10000000000000"
+					// 		width: 200
+					// 		validator: RegExpValidator { regExp: /\d*/ }
+					// 	}
+					// }
 
-					Rectangle {
-						width: 300
-						anchors {
-							left: minGasPriceRect.right
-							leftMargin: 5
-							top: parent.top
-							topMargin: 2
-						}
+					// Rectangle {
+					// 	width: 300
+					// 	anchors {
+					// 		left: minGasPriceRect.right
+					// 		leftMargin: 5
+					// 		top: parent.top
+					// 		topMargin: 2
+					// 	}
 
-						TextField {
-							id: blockExtra
-							placeholderText: "Extra"
-							width: parent.width
-							maximumLength: 1024
-						}
-					}
+					// 	TextField {
+					// 		id: blockExtra
+					// 		placeholderText: "Extra"
+					// 		width: parent.width
+					// 		maximumLength: 1024
+					// 	}
+					// }
 				}
 			}
 
diff --git a/cmd/mist/assets/qml/views/network.qml b/cmd/mist/assets/qml/views/network.qml
index d33b5773c..fe4c7734f 100644
--- a/cmd/mist/assets/qml/views/network.qml
+++ b/cmd/mist/assets/qml/views/network.qml
@@ -93,7 +93,6 @@ Rectangle {
 	         			// Check if it's mining and set it accordingly       				
          				if (miningSliderValue > 0 && !eth.miner().mining()) {
 							// If the 
-							eth.setGasPrice("10000000000000");
 	         				eth.miner().start();
 	         			} else if (miningSliderValue == 0 && eth.miner().mining()) {
 	         				eth.miner().stop();
diff --git a/cmd/mist/ui_lib.go b/cmd/mist/ui_lib.go
index 4198c6316..2679e0f95 100644
--- a/cmd/mist/ui_lib.go
+++ b/cmd/mist/ui_lib.go
@@ -175,22 +175,12 @@ func (self *UiLib) RemoveLocalTransaction(id int) {
 	//self.miner.RemoveLocalTx(id)
 }
 
-func (self *UiLib) SetGasPrice(price string) {
-	self.Miner().MinAcceptedGasPrice = ethutil.Big(price)
-}
-
-func (self *UiLib) SetExtra(extra string) {
-	self.Miner().Extra = extra
-}
-
 func (self *UiLib) ToggleMining() bool {
-	if !self.Miner().Mining() {
-		self.Miner().Start()
-
-		return true
+	if !self.eth.IsMining() {
+		err := self.eth.StartMining()
+		return err == nil
 	} else {
-		self.Miner().Stop()
-
+		self.eth.StopMining()
 		return false
 	}
 }
diff --git a/eth/backend.go b/eth/backend.go
index 9e365161d..9c497a586 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -166,18 +166,13 @@ func New(config *Config) (*Ethereum, error) {
 		DataDir:        config.DataDir,
 	}
 
-	cb, err := eth.accountManager.Coinbase()
-	if err != nil {
-		return nil, err
-	}
-
 	eth.chainManager = core.NewChainManager(blockDb, stateDb, eth.EventMux())
 	pow := ethash.New(eth.chainManager)
 	eth.txPool = core.NewTxPool(eth.EventMux())
 	eth.blockProcessor = core.NewBlockProcessor(stateDb, pow, eth.txPool, eth.chainManager, eth.EventMux())
 	eth.chainManager.SetProcessor(eth.blockProcessor)
 	eth.whisper = whisper.New()
-	eth.miner = miner.New(cb, eth, pow, config.MinerThreads)
+	eth.miner = miner.New(eth, pow, config.MinerThreads)
 
 	hasBlock := eth.chainManager.HasBlock
 	insertChain := eth.chainManager.InsertChain
@@ -211,6 +206,19 @@ func New(config *Config) (*Ethereum, error) {
 	return eth, nil
 }
 
+func (s *Ethereum) StartMining() error {
+	cb, err := s.accountManager.Coinbase()
+	if err != nil {
+		servlogger.Errorf("Cannot start mining without coinbase: %v\n", err)
+		return fmt.Errorf("no coinbase: %v", err)
+	}
+	s.miner.Start(cb)
+	return nil
+}
+
+func (s *Ethereum) StopMining()    { s.miner.Stop() }
+func (s *Ethereum) IsMining() bool { return s.miner.Mining() }
+
 func (s *Ethereum) Logger() logger.LogSystem             { return s.logger }
 func (s *Ethereum) Name() string                         { return s.net.Name }
 func (s *Ethereum) AccountManager() *accounts.Manager    { return s.accountManager }
@@ -222,7 +230,6 @@ func (s *Ethereum) Whisper() *whisper.Whisper            { return s.whisper }
 func (s *Ethereum) EventMux() *event.TypeMux             { return s.eventMux }
 func (s *Ethereum) BlockDb() ethutil.Database            { return s.blockDb }
 func (s *Ethereum) StateDb() ethutil.Database            { return s.stateDb }
-func (s *Ethereum) Miner() *miner.Miner                  { return s.miner }
 func (s *Ethereum) IsListening() bool                    { return true } // Always listening
 func (s *Ethereum) PeerCount() int                       { return s.net.PeerCount() }
 func (s *Ethereum) Peers() []*p2p.Peer                   { return s.net.Peers() }
@@ -261,7 +268,7 @@ func (s *Ethereum) Start() error {
 }
 
 func (s *Ethereum) StartForTest() {
-		jsonlogger.LogJson(&logger.LogStarting{
+	jsonlogger.LogJson(&logger.LogStarting{
 		ClientString:    s.net.Name,
 		ProtocolVersion: ProtocolVersion,
 	})
diff --git a/miner/miner.go b/miner/miner.go
index d3b1f578a..7bf67a6ec 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -17,44 +17,34 @@ type Miner struct {
 	MinAcceptedGasPrice *big.Int
 	Extra               string
 
-	Coinbase []byte
-	mining   bool
-
-	pow pow.PoW
+	mining bool
+	eth    core.Backend
+	pow    pow.PoW
 }
 
-func New(coinbase []byte, eth core.Backend, pow pow.PoW, minerThreads int) *Miner {
-	miner := &Miner{
-		Coinbase: coinbase,
-		worker:   newWorker(coinbase, eth),
-		pow:      pow,
-	}
-
-	minerThreads = 1
-	for i := 0; i < minerThreads; i++ {
-		miner.worker.register(NewCpuMiner(i, miner.pow))
-	}
-
-	return miner
+func New(eth core.Backend, pow pow.PoW, minerThreads int) *Miner {
+	// note: minerThreads is currently ignored because
+	// ethash is not thread safe.
+	return &Miner{eth: eth, pow: pow}
 }
 
 func (self *Miner) Mining() bool {
 	return self.mining
 }
 
-func (self *Miner) Start() {
+func (self *Miner) Start(coinbase []byte) {
 	self.mining = true
+	self.worker = newWorker(coinbase, self.eth)
+	self.worker.register(NewCpuMiner(0, self.pow))
 
 	self.pow.(*ethash.Ethash).UpdateDAG()
 
 	self.worker.start()
-
 	self.worker.commitNewWork()
 }
 
 func (self *Miner) Stop() {
 	self.mining = false
-
 	self.worker.stop()
 
 	//self.pow.(*ethash.Ethash).Stop()
diff --git a/xeth/xeth.go b/xeth/xeth.go
index d8dd66aec..70172a1c8 100644
--- a/xeth/xeth.go
+++ b/xeth/xeth.go
@@ -14,7 +14,6 @@ import (
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/miner"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/state"
 	"github.com/ethereum/go-ethereum/whisper"
@@ -35,7 +34,10 @@ type Backend interface {
 	StateDb() ethutil.Database
 	EventMux() *event.TypeMux
 	Whisper() *whisper.Whisper
-	Miner() *miner.Miner
+
+	IsMining() bool
+	StartMining() error
+	StopMining()
 }
 
 // Frontend should be implemented by users of XEth. Its methods are
@@ -65,7 +67,6 @@ type XEth struct {
 	accountManager *accounts.Manager
 	state          *State
 	whisper        *Whisper
-	miner          *miner.Miner
 
 	frontend Frontend
 }
@@ -87,7 +88,6 @@ func New(eth Backend, frontend Frontend) *XEth {
 		chainManager:   eth.ChainManager(),
 		accountManager: eth.AccountManager(),
 		whisper:        NewWhisper(eth.Whisper()),
-		miner:          eth.Miner(),
 		frontend:       frontend,
 	}
 	if frontend == nil {
@@ -104,7 +104,6 @@ func (self *XEth) WithState(statedb *state.StateDB) *XEth {
 		blockProcessor: self.blockProcessor,
 		chainManager:   self.chainManager,
 		whisper:        self.whisper,
-		miner:          self.miner,
 	}
 
 	xeth.state = NewState(xeth, statedb)
@@ -112,8 +111,7 @@ func (self *XEth) WithState(statedb *state.StateDB) *XEth {
 }
 func (self *XEth) State() *State { return self.state }
 
-func (self *XEth) Whisper() *Whisper   { return self.whisper }
-func (self *XEth) Miner() *miner.Miner { return self.miner }
+func (self *XEth) Whisper() *Whisper { return self.whisper }
 
 func (self *XEth) BlockByHash(strHash string) *Block {
 	hash := fromHex(strHash)
@@ -172,18 +170,19 @@ func (self *XEth) PeerCount() int {
 }
 
 func (self *XEth) IsMining() bool {
-	return self.miner.Mining()
+	return self.eth.IsMining()
 }
 
 func (self *XEth) SetMining(shouldmine bool) bool {
-	ismining := self.miner.Mining()
+	ismining := self.eth.IsMining()
 	if shouldmine && !ismining {
-		self.miner.Start()
+		err := self.eth.StartMining()
+		return err == nil
 	}
 	if ismining && !shouldmine {
-		self.miner.Stop()
+		self.eth.StopMining()
 	}
-	return self.miner.Mining()
+	return self.eth.IsMining()
 }
 
 func (self *XEth) IsListening() bool {