eth, eth/downloader, miner: use download events to check miner start

core/error.go

@@ -42,8 +42,8 @@ func (err *UncleErr) Error() string {
 	return err.Message
 }
 
-func UncleError(str string) error {
-	return &UncleErr{Message: str}
+func UncleError(format string, v ...interface{}) error {
+	return &UncleErr{Message: fmt.Sprintf(format, v...)}
 }
 
 func IsUncleErr(err error) bool {

core/manager.go

@@ -3,10 +3,12 @@ package core
 import (
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/p2p"
 )
 
+// TODO move this to types?
 type Backend interface {
 	AccountManager() *accounts.Manager
 	BlockProcessor() *BlockProcessor
@@ -18,4 +20,5 @@ type Backend interface {
 	BlockDb() common.Database
 	StateDb() common.Database
 	EventMux() *event.TypeMux
+	Downloader() *downloader.Downloader
 }

eth/backend.go

@@ -265,12 +265,12 @@ func New(config *Config) (*Ethereum, error) {
 	}
 
 	eth.chainManager = core.NewChainManager(blockDb, stateDb, eth.EventMux())
-	eth.downloader = downloader.New(eth.chainManager.HasBlock, eth.chainManager.GetBlock)
+	eth.downloader = downloader.New(eth.EventMux(), eth.chainManager.HasBlock, eth.chainManager.GetBlock)
 	eth.pow = ethash.New()
 	eth.txPool = core.NewTxPool(eth.EventMux(), eth.chainManager.State, eth.chainManager.GasLimit)
 	eth.blockProcessor = core.NewBlockProcessor(stateDb, extraDb, eth.pow, eth.txPool, eth.chainManager, eth.EventMux())
 	eth.chainManager.SetProcessor(eth.blockProcessor)
-	eth.miner = miner.New(eth, eth.pow)
+	eth.miner = miner.New(eth, eth.EventMux(), eth.pow)
 	eth.miner.SetGasPrice(config.GasPrice)
 
 	eth.protocolManager = NewProtocolManager(config.ProtocolVersion, config.NetworkId, eth.eventMux, eth.txPool, eth.chainManager, eth.downloader)

eth/downloader/downloader.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
@@ -55,6 +56,8 @@ type hashPack struct {
 }
 
 type Downloader struct {
+	mux *event.TypeMux
+
 	mu    sync.RWMutex
 	queue *queue
 	peers *peerSet
@@ -76,8 +79,9 @@ type Downloader struct {
 	cancelLock sync.RWMutex  // Lock to protect the cancel channel in delivers
 }
 
-func New(hasBlock hashCheckFn, getBlock getBlockFn) *Downloader {
+func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock getBlockFn) *Downloader {
 	downloader := &Downloader{
+		mux:       mux,
 		queue:     newQueue(),
 		peers:     newPeerSet(),
 		hasBlock:  hasBlock,
@@ -93,6 +97,11 @@ func (d *Downloader) Stats() (current int, max int) {
 	return d.queue.Size()
 }
 
+// Synchronising returns the state of the downloader
+func (d *Downloader) Synchronising() bool {
+	return atomic.LoadInt32(&d.synchronising) > 0
+}
+
 // RegisterPeer injects a new download peer into the set of block source to be
 // used for fetching hashes and blocks from.
 func (d *Downloader) RegisterPeer(id string, head common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) error {
@@ -129,6 +138,9 @@ func (d *Downloader) Synchronise(id string, hash common.Hash) error {
 	if atomic.CompareAndSwapInt32(&d.notified, 0, 1) {
 		glog.V(logger.Info).Infoln("Block synchronisation started")
 	}
+
+	d.mux.Post(StartEvent{})
+
 	// Create cancel channel for aborting mid-flight
 	d.cancelLock.Lock()
 	d.cancelCh = make(chan struct{})
@@ -166,6 +178,9 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash) (err error) {
 		// reset on error
 		if err != nil {
 			d.queue.Reset()
+			d.mux.Post(FailedEvent{err})
+		} else {
+			d.mux.Post(DoneEvent{})
 		}
 	}()
 

eth/downloader/events.go

@@ -0,0 +1,5 @@
+package downloader
+
+type DoneEvent struct{}
+type StartEvent struct{}
+type FailedEvent struct{ Err error }

miner/miner.go

@@ -2,33 +2,63 @@ package miner
 
 import (
 	"math/big"
+	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/pow"
 )
 
 type Miner struct {
+	mux *event.TypeMux
+
 	worker *worker
 
 	MinAcceptedGasPrice *big.Int
 
-	threads int
-	mining  bool
-	eth     core.Backend
-	pow     pow.PoW
+	threads  int
+	coinbase common.Address
+	mining   int32
+	eth      core.Backend
+	pow      pow.PoW
+
+	canStart    int32 // can start indicates whether we can start the mining operation
+	shouldStart int32 // should start indicates whether we should start after sync
 }
 
-func New(eth core.Backend, pow pow.PoW) *Miner {
-	return &Miner{eth: eth, pow: pow, worker: newWorker(common.Address{}, eth)}
+func New(eth core.Backend, mux *event.TypeMux, pow pow.PoW) *Miner {
+	miner := &Miner{eth: eth, mux: mux, pow: pow, worker: newWorker(common.Address{}, eth), canStart: 1}
+	go miner.update()
+
+	return miner
 }
 
-func (self *Miner) Mining() bool {
-	return self.mining
+func (self *Miner) update() {
+	events := self.mux.Subscribe(downloader.StartEvent{}, downloader.DoneEvent{}, downloader.FailedEvent{})
+	for ev := range events.Chan() {
+		switch ev.(type) {
+		case downloader.StartEvent:
+			atomic.StoreInt32(&self.canStart, 0)
+			if self.Mining() {
+				self.Stop()
+				glog.V(logger.Info).Infoln("Mining operation aborted due to sync operation")
+			}
+		case downloader.DoneEvent, downloader.FailedEvent:
+			shouldStart := atomic.LoadInt32(&self.shouldStart) == 1
+
+			atomic.StoreInt32(&self.canStart, 1)
+			atomic.StoreInt32(&self.shouldStart, 0)
+			if shouldStart {
+				self.Start(self.coinbase, self.threads)
+			}
+		}
+	}
 }
 
 func (m *Miner) SetGasPrice(price *big.Int) {
@@ -41,34 +71,46 @@ func (m *Miner) SetGasPrice(price *big.Int) {
 }
 
 func (self *Miner) Start(coinbase common.Address, threads int) {
+	atomic.StoreInt32(&self.shouldStart, 1)
+	self.threads = threads
+	self.worker.coinbase = coinbase
+
+	if atomic.LoadInt32(&self.canStart) == 0 {
+		glog.V(logger.Info).Infoln("Can not start mining operation due to network sync (starts when finished)")
+		return
+	}
 
-	self.mining = true
+	atomic.StoreInt32(&self.mining, 1)
 
 	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
+	atomic.StoreInt32(&self.mining, 0)
+	atomic.StoreInt32(&self.shouldStart, 0)
 }
 
 func (self *Miner) Register(agent Agent) {
-	if self.mining {
+	if atomic.LoadInt32(&self.mining) == 0 {
 		agent.Start()
 	}
 
 	self.worker.register(agent)
 }
 
+func (self *Miner) Mining() bool {
+	return atomic.LoadInt32(&self.mining) > 0
+}
+
 func (self *Miner) HashRate() int64 {
 	return self.pow.GetHashrate()
 }