github.com/daragao/go-ethereum@v1.8.14-0.20180809141559-45eaef243198/miner/agent.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package miner
    18  
    19  import (
    20  	"sync"
    21  	"sync/atomic"
    22  
    23  	"github.com/ethereum/go-ethereum/consensus"
    24  	"github.com/ethereum/go-ethereum/log"
    25  )
    26  
    27  type CpuAgent struct {
    28  	mu sync.Mutex
    29  
    30  	taskCh        chan *Package
    31  	returnCh      chan<- *Package
    32  	stop          chan struct{}
    33  	quitCurrentOp chan struct{}
    34  
    35  	chain  consensus.ChainReader
    36  	engine consensus.Engine
    37  
    38  	started int32 // started indicates whether the agent is currently started
    39  }
    40  
    41  func NewCpuAgent(chain consensus.ChainReader, engine consensus.Engine) *CpuAgent {
    42  	agent := &CpuAgent{
    43  		chain:  chain,
    44  		engine: engine,
    45  		stop:   make(chan struct{}, 1),
    46  		taskCh: make(chan *Package, 1),
    47  	}
    48  	return agent
    49  }
    50  
    51  func (self *CpuAgent) AssignTask(p *Package) {
    52  	if atomic.LoadInt32(&self.started) == 1 {
    53  		self.taskCh <- p
    54  	}
    55  }
    56  func (self *CpuAgent) DeliverTo(ch chan<- *Package) { self.returnCh = ch }
    57  
    58  func (self *CpuAgent) Start() {
    59  	if !atomic.CompareAndSwapInt32(&self.started, 0, 1) {
    60  		return // agent already started
    61  	}
    62  	go self.update()
    63  }
    64  
    65  func (self *CpuAgent) Stop() {
    66  	if !atomic.CompareAndSwapInt32(&self.started, 1, 0) {
    67  		return // agent already stopped
    68  	}
    69  	self.stop <- struct{}{}
    70  done:
    71  	// Empty work channel
    72  	for {
    73  		select {
    74  		case <-self.taskCh:
    75  		default:
    76  			break done
    77  		}
    78  	}
    79  }
    80  
    81  func (self *CpuAgent) update() {
    82  out:
    83  	for {
    84  		select {
    85  		case p := <-self.taskCh:
    86  			self.mu.Lock()
    87  			if self.quitCurrentOp != nil {
    88  				close(self.quitCurrentOp)
    89  			}
    90  			self.quitCurrentOp = make(chan struct{})
    91  			go self.mine(p, self.quitCurrentOp)
    92  			self.mu.Unlock()
    93  		case <-self.stop:
    94  			self.mu.Lock()
    95  			if self.quitCurrentOp != nil {
    96  				close(self.quitCurrentOp)
    97  				self.quitCurrentOp = nil
    98  			}
    99  			self.mu.Unlock()
   100  			break out
   101  		}
   102  	}
   103  }
   104  
   105  func (self *CpuAgent) mine(p *Package, stop <-chan struct{}) {
   106  	var err error
   107  	if p.Block, err = self.engine.Seal(self.chain, p.Block, stop); p.Block != nil {
   108  		log.Info("Successfully sealed new block", "number", p.Block.Number(), "hash", p.Block.Hash())
   109  		self.returnCh <- p
   110  	} else {
   111  		if err != nil {
   112  			log.Warn("Block sealing failed", "err", err)
   113  		}
   114  		self.returnCh <- nil
   115  	}
   116  }