path: root/miner/worker.go

package miner

import (
    "fmt"
    "math/big"
    "sort"
    "sync"
    "sync/atomic"

    "github.com/ethereum/go-ethereum/accounts"
    "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/event"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/pow"
    "gopkg.in/fatih/set.v0"
)

var jsonlogger = logger.NewJsonLogger()

// Work holds the current work
type Work struct {
    Number    uint64
    Nonce     uint64
    MixDigest []byte
    SeedHash  []byte
}

// Agent can register themself with the worker
type Agent interface {
    Work() chan<- *types.Block
    SetReturnCh(chan<- *types.Block)
    Stop()
    Start()
    GetHashRate() int64
}

// environment is the workers current environment and holds
// all of the current state information
type environment struct {
    totalUsedGas       *big.Int           // total gas usage in the cycle
    state              *state.StateDB     // apply state changes here
    coinbase           *state.StateObject // the miner's account
    block              *types.Block       // the new block
    ancestors          *set.Set           // ancestor set (used for checking uncle parent validity)
    family             *set.Set           // family set (used for checking uncle invalidity)
    uncles             *set.Set           // uncle set
    remove             *set.Set           // tx which will be removed
    tcount             int                // tx count in cycle
    ignoredTransactors *set.Set
    lowGasTransactors  *set.Set
    ownedAccounts      *set.Set
    lowGasTxs          types.Transactions
}

// env returns a new environment for the current cycle
func env(block *types.Block, eth core.Backend) *environment {
    state := state.New(block.Root(), eth.StateDb())
    env := &environment{
        totalUsedGas: new(big.Int),
        state:        state,
        block:        block,
        ancestors:    set.New(),
        family:       set.New(),
        uncles:       set.New(),
        coinbase:     state.GetOrNewStateObject(block.Coinbase()),
    }

    return env
}

// worker is the main object which takes care of applying messages to the new state
type worker struct {
    mu sync.Mutex

    agents []Agent
    recv   chan *types.Block
    mux    *event.TypeMux
    quit   chan struct{}
    pow    pow.PoW

    eth   core.Backend
    chain *core.ChainManager
    proc  *core.BlockProcessor

    coinbase common.Address
    gasPrice *big.Int
    extra    []byte

    currentMu sync.Mutex
    current   *environment

    uncleMu        sync.Mutex
    possibleUncles map[common.Hash]*types.Block

    txQueueMu sync.Mutex
    txQueue   map[common.Hash]*types.Transaction

    // atomic status counters
    mining int32
    atWork int32
}

func newWorker(coinbase common.Address, eth core.Backend) *worker {
    worker := &worker{
        eth:            eth,
        mux:            eth.EventMux(),
        recv:           make(chan *types.Block),
        gasPrice:       new(big.Int),
        chain:          eth.ChainManager(),
        proc:           eth.BlockProcessor(),
        possibleUncles: make(map[common.Hash]*types.Block),
        coinbase:       coinbase,
        txQueue:        make(map[common.Hash]*types.Transaction),
        quit:           make(chan struct{}),
    }
    go worker.update()
    go worker.wait()

    worker.commitNewWork()

    return worker
}

func (self *worker) pendingState() *state.StateDB {
    self.currentMu.Lock()
    defer self.currentMu.Unlock()

    return self.current.state
}

func (self *worker) pendingBlock() *types.Block {
    self.currentMu.Lock()
    defer self.currentMu.Unlock()

    return self.current.block
}

func (self *worker) start() {
    self.mu.Lock()
    defer self.mu.Unlock()

    atomic.StoreInt32(&self.mining, 1)

    // spin up agents
    for _, agent := range self.agents {
        agent.Start()
    }
}

func (self *worker) stop() {
    self.mu.Lock()
    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)
    atomic.StoreInt32(&self.atWork, 0)
}

func (self *worker) register(agent Agent) {
    self.mu.Lock()
    defer self.mu.Unlock()
    self.agents = append(self.agents, agent)
    agent.SetReturnCh(self.recv)
}

func (self *worker) update() {
    events := self.mux.Subscribe(core.ChainHeadEvent{}, core.ChainSideEvent{}, core.TxPreEvent{})

out:
    for {
        select {
        case event := <-events.Chan():
            switch ev := event.(type) {
            case core.ChainHeadEvent:
                self.commitNewWork()
            case core.ChainSideEvent:
                self.uncleMu.Lock()
                self.possibleUncles[ev.Block.Hash()] = ev.Block
                self.uncleMu.Unlock()
            case core.TxPreEvent:
                // Apply transaction to the pending state if we're not mining
                if atomic.LoadInt32(&self.mining) == 0 {
                    self.mu.Lock()
                    self.commitTransactions(types.Transactions{ev.Tx})
                    self.mu.Unlock()
                }
            }
        case <-self.quit:
            break out
        }
    }

    events.Unsubscribe()
}

func (self *worker) wait() {
    for {
        for block := range self.recv {
            atomic.AddInt32(&self.atWork, -1)

            if block == nil {
                continue
            }

            if _, err := self.chain.InsertChain(types.Blocks{block}); err == nil {
                for _, uncle := range block.Uncles() {
                    delete(self.possibleUncles, uncle.Hash())
                }
                self.mux.Post(core.NewMinedBlockEvent{block})

                glog.V(logger.Info).Infof("🔨  Mined block #%v", block.Number())

                jsonlogger.LogJson(&logger.EthMinerNewBlock{
                    BlockHash:     block.Hash().Hex(),
                    BlockNumber:   block.Number(),
                    ChainHeadHash: block.ParentHeaderHash.Hex(),
                    BlockPrevHash: block.ParentHeaderHash.Hex(),
                })
            } else {
                self.commitNewWork()
            }
        }
    }
}

func (self *worker) push() {
    if atomic.LoadInt32(&self.mining) == 1 {
        self.current.block.Header().GasUsed = self.current.totalUsedGas
        self.current.block.SetRoot(self.current.state.Root())

        // push new work to agents
        for _, agent := range self.agents {
            atomic.AddInt32(&self.atWork, 1)

            if agent.Work() != nil {
                agent.Work() <- self.current.block.Copy()
            } else {
                common.Report(fmt.Sprintf("%v %T\n", agent, agent))
            }
        }
    }
}

func (self *worker) makeCurrent() {
    block := self.chain.NewBlock(self.coinbase)
    if block.Time() == self.chain.CurrentBlock().Time() {
        block.Header().Time++
    }
    block.Header().Extra = self.extra

    current := env(block, self.eth)
    for _, ancestor := range self.chain.GetAncestors(block, 7) {
        for _, uncle := range ancestor.Uncles() {
            current.family.Add(uncle.Hash())
        }
        current.family.Add(ancestor.Hash())
        current.ancestors.Add(ancestor.Hash())
    }
    accounts, _ := self.eth.AccountManager().Accounts()
    // Keep track of transactions which return errors so they can be removed
    current.remove = set.New()
    current.tcount = 0
    current.ignoredTransactors = set.New()
    current.lowGasTransactors = set.New()
    current.ownedAccounts = accountAddressesSet(accounts)

    parent := self.chain.GetBlock(current.block.ParentHash())
    current.coinbase.SetGasPool(core.CalcGasLimit(parent))

    self.current = current
}

func (w *worker) setGasPrice(p *big.Int) {
    w.mu.Lock()
    defer w.mu.Unlock()

    // calculate the minimal gas price the miner accepts when sorting out transactions.
    const pct = int64(90)
    w.gasPrice = gasprice(p, pct)

    w.mux.Post(core.GasPriceChanged{w.gasPrice})
}

func (self *worker) commitNewWork() {
    self.mu.Lock()
    defer self.mu.Unlock()
    self.uncleMu.Lock()
    defer self.uncleMu.Unlock()
    self.currentMu.Lock()
    defer self.currentMu.Unlock()

    self.makeCurrent()
    current := self.current

    transactions := self.eth.TxPool().GetTransactions()
    sort.Sort(types.TxByNonce{transactions})

    // commit transactions for this run
    self.commitTransactions(transactions)
    self.eth.TxPool().RemoveTransactions(current.lowGasTxs)

    var (
        uncles    []*types.Header
        badUncles []common.Hash
    )
    for hash, uncle := range self.possibleUncles {
        if len(uncles) == 2 {
            break
        }

        if err := self.commitUncle(uncle.Header()); err != nil {
            if glog.V(logger.Ridiculousness) {
                glog.V(logger.Detail).Infof("Bad uncle found and will be removed (%x)\n", hash[:4])
                glog.V(logger.Detail).Infoln(uncle)
            }

            badUncles = append(badUncles, hash)
        } else {
            glog.V(logger.Debug).Infof("commiting %x as uncle\n", hash[:4])
            uncles = append(uncles, uncle.Header())
        }
    }

    // We only care about logging if we're actually mining
    if atomic.LoadInt32(&self.mining) == 1 {
        glog.V(logger.Info).Infof("commit new work on block %v with %d txs & %d uncles\n", current.block.Number(), current.tcount, len(uncles))
    }

    for _, hash := range badUncles {
        delete(self.possibleUncles, hash)
    }

    self.current.block.SetUncles(uncles)

    core.AccumulateRewards(self.current.state, self.current.block)

    self.current.state.Update()

    self.push()
}

var (
    inclusionReward = new(big.Int).Div(core.BlockReward, big.NewInt(32))
    _uncleReward    = new(big.Int).Mul(core.BlockReward, big.NewInt(15))
    uncleReward     = new(big.Int).Div(_uncleReward, big.NewInt(16))
)

func (self *worker) commitUncle(uncle *types.Header) error {
    if self.current.uncles.Has(uncle.Hash()) {
        // Error not unique
        return core.UncleError("Uncle not unique")
    }
    self.current.uncles.Add(uncle.Hash())

    if !self.current.ancestors.Has(uncle.ParentHash) {
        return core.UncleError(fmt.Sprintf("Uncle's parent unknown (%x)", uncle.ParentHash[0:4]))
    }

    if self.current.family.Has(uncle.Hash()) {
        return core.UncleError(fmt.Sprintf("Uncle already in family (%x)", uncle.Hash()))
    }

    return nil
}

func (self *worker) commitTransactions(transactions types.Transactions) {
    current := self.current

    for _, tx := range transactions {
        // We can skip err. It has already been validated in the tx pool
        from, _ := tx.From()

        // Check if it falls within margin. Txs from owned accounts are always processed.
        if tx.GasPrice().Cmp(self.gasPrice) < 0 && !current.ownedAccounts.Has(from) {
            // ignore the transaction and transactor. We ignore the transactor
            // because nonce will fail after ignoring this transaction so there's
            // no point
            current.lowGasTransactors.Add(from)

            glog.V(logger.Info).Infof("transaction(%x) below gas price (tx=%v ask=%v). All sequential txs from this address(%x) will be ignored\n", tx.Hash().Bytes()[:4], common.CurrencyToString(tx.GasPrice()), common.CurrencyToString(self.gasPrice), from[:4])
        }

        // Continue with the next transaction if the transaction sender is included in
        // the low gas tx set. This will also remove the tx and all sequential transaction
        // from this transactor
        if current.lowGasTransactors.Has(from) {
            // add tx to the low gas set. This will be removed at the end of the run
            // owned accounts are ignored
            if !current.ownedAccounts.Has(from) {
                current.lowGasTxs = append(current.lowGasTxs, tx)
            }
            continue
        }

        // Move on to the next transaction when the transactor is in ignored transactions set
        // This may occur when a transaction hits the gas limit. When a gas limit is hit and
        // the transaction is processed (that could potentially be included in the block) it
        // will throw a nonce error because the previous transaction hasn't been processed.
        // Therefor we need to ignore any transaction after the ignored one.
        if current.ignoredTransactors.Has(from) {
            continue
        }

        self.current.state.StartRecord(tx.Hash(), common.Hash{}, 0)

        err := self.commitTransaction(tx)
        switch {
        case core.IsNonceErr(err) || core.IsInvalidTxErr(err):
            // Remove invalid transactions
            from, _ := tx.From()

            self.chain.TxState().RemoveNonce(from, tx.Nonce())
            current.remove.Add(tx.Hash())

            if glog.V(logger.Detail) {
                glog.Infof("TX (%x) failed, will be removed: %v\n", tx.Hash().Bytes()[:4], err)
            }
        case state.IsGasLimitErr(err):
            from, _ := tx.From()
            // ignore the transactor so no nonce errors will be thrown for this account
            // next time the worker is run, they'll be picked up again.
            current.ignoredTransactors.Add(from)

            glog.V(logger.Detail).Infof("Gas limit reached for (%x) in this block. Continue to try smaller txs\n", from[:4])
        default:
            current.tcount++
        }
    }
}

func (self *worker) commitTransaction(tx *types.Transaction) error {
    snap := self.current.state.Copy()
    receipt, _, err := self.proc.ApplyTransaction(self.current.coinbase, self.current.state, self.current.block, tx, self.current.totalUsedGas, true)
    if err != nil && (core.IsNonceErr(err) || state.IsGasLimitErr(err) || core.IsInvalidTxErr(err)) {
        self.current.state.Set(snap)
        return err
    }

    self.current.block.AddTransaction(tx)
    self.current.block.AddReceipt(receipt)

    return nil
}

// TODO: remove or use
func (self *worker) HashRate() int64 {
    return 0
}

// gasprice calculates a reduced gas price based on the pct
// XXX Use big.Rat?
func gasprice(price *big.Int, pct int64) *big.Int {
    p := new(big.Int).Set(price)
    p.Div(p, big.NewInt(100))
    p.Mul(p, big.NewInt(pct))
    return p
}

func accountAddressesSet(accounts []accounts.Account) *set.Set {
    accountSet := set.New()
    for _, account := range accounts {
        accountSet.Add(account.Address)
    }
    return accountSet
}