path: root/miner/agent.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package miner

import (
    "sync"

    "sync/atomic"

    "github.com/ethereum/go-ethereum/consensus"
    "github.com/ethereum/go-ethereum/log"
)

type CpuAgent struct {
    mu sync.Mutex

    workCh        chan *Work
    stop          chan struct{}
    quitCurrentOp chan struct{}
    returnCh      chan<- *Result

    chain  consensus.ChainReader
    engine consensus.Engine

    isMining int32 // isMining indicates whether the agent is currently mining
}

func NewCpuAgent(chain consensus.ChainReader, engine consensus.Engine) *CpuAgent {
    miner := &CpuAgent{
        chain:  chain,
        engine: engine,
        stop:   make(chan struct{}, 1),
        workCh: make(chan *Work, 1),
    }
    return miner
}

func (self *CpuAgent) Work() chan<- *Work            { return self.workCh }
func (self *CpuAgent) SetReturnCh(ch chan<- *Result) { self.returnCh = ch }

func (self *CpuAgent) Stop() {
    self.stop <- struct{}{}
}

func (self *CpuAgent) Start() {
    if !atomic.CompareAndSwapInt32(&self.isMining, 0, 1) {
        return // agent already started
    }
    go self.update()
}

func (self *CpuAgent) update() {
out:
    for {
        select {
        case work := <-self.workCh:
            self.mu.Lock()
            if self.quitCurrentOp != nil {
                close(self.quitCurrentOp)
            }
            self.quitCurrentOp = make(chan struct{})
            go self.mine(work, self.quitCurrentOp)
            self.mu.Unlock()
        case <-self.stop:
            self.mu.Lock()
            if self.quitCurrentOp != nil {
                close(self.quitCurrentOp)
                self.quitCurrentOp = nil
            }
            self.mu.Unlock()
            break out
        }
    }

done:
    // Empty work channel
    for {
        select {
        case <-self.workCh:
        default:
            break done
        }
    }
    atomic.StoreInt32(&self.isMining, 0)
}

func (self *CpuAgent) mine(work *Work, stop <-chan struct{}) {
    if result, err := self.engine.Seal(self.chain, work.Block, stop); result != nil {
        log.Info("Successfully sealed new block", "number", result.Number(), "hash", result.Hash())
        self.returnCh <- &Result{work, result}
    } else {
        if err != nil {
            log.Warn("Block sealing failed", "err", err)
        }
        self.returnCh <- nil
    }
}

func (self *CpuAgent) GetHashRate() int64 {
    if pow, ok := self.engine.(consensus.PoW); ok {
        return int64(pow.Hashrate())
    }
    return 0
}