// Copyright 2017 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 ethash
import (
"bytes"
"context"
crand "crypto/rand"
"encoding/json"
"errors"
"math"
"math/big"
"math/rand"
"net/http"
"runtime"
"sync"
"time"
"github.com/ava-labs/coreth/consensus"
"github.com/ava-labs/coreth/core/types"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
)
const (
// staleThreshold is the maximum depth of the acceptable stale but valid ethash solution.
staleThreshold = 7
)
var (
errNoMiningWork = errors.New("no mining work available yet")
errInvalidSealResult = errors.New("invalid or stale proof-of-work solution")
)
// Seal implements consensus.Engine, attempting to find a nonce that satisfies
// the block's difficulty requirements.
func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
// If we're running a fake PoW, simply return a 0 nonce immediately
if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
header := block.Header()
header.Nonce, header.MixDigest = types.BlockNonce{}, common.Hash{}
select {
case results <- block.WithSeal(header):
default:
ethash.config.Log.Warn("Sealing result is not read by miner", "mode", "fake", "sealhash", ethash.SealHash(block.Header()))
}
return nil
}
// If we're running a shared PoW, delegate sealing to it
if ethash.shared != nil {
return ethash.shared.Seal(chain, block, results, stop)
}
// Create a runner and the multiple search threads it directs
abort := make(chan struct{})
ethash.lock.Lock()
threads := ethash.threads
if ethash.rand == nil {
seed, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
if err != nil {
ethash.lock.Unlock()
return err
}
ethash.rand = rand.New(rand.NewSource(seed.Int64()))
}
ethash.lock.Unlock()
if threads == 0 {
threads = runtime.NumCPU()
}
if threads < 0 {
threads = 0 // Allows disabling local mining without extra logic around local/remote
}
// Push new work to remote sealer
if ethash.remote != nil {
ethash.remote.workCh <- &sealTask{block: block, results: results}
}
var (
pend sync.WaitGroup
locals = make(chan *types.Block)
)
for i := 0; i <