cmd/geth, miner, backend, xeth: Fixed miner threads to be settable

Miner threads are now settable through the admin interface (closes #897)
and specify 0 CPU worker threads when eth_getWork is called (closes #916)

miner/agent.go

@@ -10,7 +10,7 @@ import (
 	"github.com/ethereum/go-ethereum/pow"
 )
 
-type CpuMiner struct {
+type CpuAgent struct {
 	chMu          sync.Mutex
 	c             chan *types.Block
 	quit          chan struct{}
@@ -21,8 +21,8 @@ type CpuMiner struct {
 	pow   pow.PoW
 }
 
-func NewCpuMiner(index int, pow pow.PoW) *CpuMiner {
-	miner := &CpuMiner{
+func NewCpuAgent(index int, pow pow.PoW) *CpuAgent {
+	miner := &CpuAgent{
 		pow:   pow,
 		index: index,
 	}
@@ -30,16 +30,16 @@ func NewCpuMiner(index int, pow pow.PoW) *CpuMiner {
 	return miner
 }
 
-func (self *CpuMiner) Work() chan<- *types.Block          { return self.c }
-func (self *CpuMiner) Pow() pow.PoW                       { return self.pow }
-func (self *CpuMiner) SetReturnCh(ch chan<- *types.Block) { self.returnCh = ch }
+func (self *CpuAgent) Work() chan<- *types.Block          { return self.c }
+func (self *CpuAgent) Pow() pow.PoW                       { return self.pow }
+func (self *CpuAgent) SetReturnCh(ch chan<- *types.Block) { self.returnCh = ch }
 
-func (self *CpuMiner) Stop() {
+func (self *CpuAgent) Stop() {
 	close(self.quit)
 	close(self.quitCurrentOp)
 }
 
-func (self *CpuMiner) Start() {
+func (self *CpuAgent) Start() {
 	self.quit = make(chan struct{})
 	self.quitCurrentOp = make(chan struct{}, 1)
 	self.c = make(chan *types.Block, 1)
@@ -47,7 +47,7 @@ func (self *CpuMiner) Start() {
 	go self.update()
 }
 
-func (self *CpuMiner) update() {
+func (self *CpuAgent) update() {
 out:
 	for {
 		select {
@@ -76,7 +76,7 @@ done:
 	}
 }
 
-func (self *CpuMiner) mine(block *types.Block) {
+func (self *CpuAgent) mine(block *types.Block) {
 	glog.V(logger.Debug).Infof("(re)started agent[%d]. mining...\n", self.index)
 
 	// Reset the channel
@@ -95,6 +95,6 @@ func (self *CpuMiner) mine(block *types.Block) {
 	}
 }
 
-func (self *CpuMiner) GetHashRate() int64 {
+func (self *CpuAgent) GetHashRate() int64 {
 	return self.pow.GetHashrate()
 }

miner/miner.go

@@ -23,16 +23,8 @@ type Miner struct {
 	pow     pow.PoW
 }
 
-func New(eth core.Backend, pow pow.PoW, minerThreads int) *Miner {
-	// note: minerThreads is currently ignored because
-	// ethash is not thread safe.
-	miner := &Miner{eth: eth, pow: pow, worker: newWorker(common.Address{}, eth)}
-	for i := 0; i < minerThreads; i++ {
-		miner.worker.register(NewCpuMiner(i, pow))
-	}
-	miner.threads = minerThreads
-
-	return miner
+func New(eth core.Backend, pow pow.PoW) *Miner {
+	return &Miner{eth: eth, pow: pow, worker: newWorker(common.Address{}, eth)}
 }
 
 func (self *Miner) Mining() bool {
@@ -48,15 +40,27 @@ func (m *Miner) SetGasPrice(price *big.Int) {
 	m.worker.gasPrice = price
 }
 
-func (self *Miner) Start(coinbase common.Address) {
-	glog.V(logger.Info).Infoln("Starting mining operation")
+func (self *Miner) Start(coinbase common.Address, threads int) {
 
 	self.mining = true
+
+	for i := 0; i < threads; i++ {
+		self.worker.register(NewCpuAgent(i, self.pow))
+	}
+	self.threads = threads
+
+	glog.V(logger.Info).Infof("Starting mining operation (CPU=%d TOT=%d)\n", threads, len(self.worker.agents))
+
 	self.worker.coinbase = coinbase
 	self.worker.start()
 	self.worker.commitNewWork()
 }
 
+func (self *Miner) Stop() {
+	self.worker.stop()
+	self.mining = false
+}
+
 func (self *Miner) Register(agent Agent) {
 	if self.mining {
 		agent.Start()
@@ -65,11 +69,6 @@ func (self *Miner) Register(agent Agent) {
 	self.worker.register(agent)
 }
 
-func (self *Miner) Stop() {
-	self.mining = false
-	self.worker.stop()
-}
-
 func (self *Miner) HashRate() int64 {
 	return self.worker.HashRate()
 }

miner/worker.go

@@ -141,7 +141,6 @@ func (self *worker) start() {
 	for _, agent := range self.agents {
 		agent.Start()
 	}
-
 }
 
 func (self *worker) stop() {
@@ -149,10 +148,16 @@ func (self *worker) stop() {
 	defer self.mu.Unlock()
 
 	if atomic.LoadInt32(&self.mining) == 1 {
+		var keep []Agent
 		// stop all agents
 		for _, agent := range self.agents {
 			agent.Stop()
+			// keep all that's not a cpu agent
+			if _, ok := agent.(*CpuAgent); !ok {
+				keep = append(keep, agent)
+			}
 		}
+		self.agents = keep
 	}
 
 	atomic.StoreInt32(&self.mining, 0)