remove prefetch

core/puissant.go

@@ -232,7 +232,7 @@ func (pc *snapshotSet) revert(bID types.PuissantID, currEnv *MinerEnvironment) {
 
 	if currEnv.TxCount != load.storeEnv.TxCount {
 		// should reload work env
-		load.storeEnv.State.TransferPrefetcher(currEnv.State)
+		//load.storeEnv.State.TransferPrefetcher(currEnv.State)
 		*currEnv = *load.storeEnv
 	}
 

core/puissant_env.go

@@ -49,7 +49,7 @@ func (env *MinerEnvironment) Copy() *MinerEnvironment {
 // the go-routine leak can happen.
 func (env *MinerEnvironment) Discard() {
 	if env.State != nil {
-		env.State.StopPrefetcher()
+		//env.State.StopPrefetcher()
 	}
 }
 

miner/worker.go

@@ -137,8 +137,6 @@ type worker struct {
 
 	wg sync.WaitGroup
 
-	current *core.MinerEnvironment // An environment for current running cycle.
-
 	mu       sync.RWMutex // The lock used to protect the coinbase and extra fields
 	coinbase common.Address
 	extra    []byte
@@ -447,11 +445,6 @@ func (w *worker) newWorkLoop(recommit time.Duration) {
 func (w *worker) mainLoop() {
 	defer w.wg.Done()
 	defer w.chainHeadSub.Unsubscribe()
-	defer func() {
-		if w.current != nil {
-			w.current.Discard()
-		}
-	}()
 
 	for {
 		select {
@@ -700,7 +693,7 @@ func (w *worker) prepareWork(genParams *generateParams) (*core.MinerEnvironment,
 	// Could potentially happen if starting to mine in an odd state.
 	// Note genParams.coinbase can be different with header.Coinbase
 	// since clique algorithm can modify the coinbase field in header.
-	env, err := w.makeEnv(parent, header, genParams.coinbase, genParams.prevWork)
+	env, err := w.makeEnv(parent, header, genParams.coinbase)
 	if err != nil {
 		log.Error("Failed to create sealing context", "err", err)
 		return nil, err

miner/worker_puissant.go

@@ -34,8 +34,7 @@ type generateParams struct {
 	coinbase    common.Address    // The fee recipient address for including transaction
 	random      common.Hash       // The randomness generated by beacon chain, empty before the merge
 	withdrawals types.Withdrawals // List of withdrawals to include in block.
-	prevWork    *core.MinerEnvironment
-	noTxs       bool // Flag whether an empty block without any transaction is expected
+	noTxs       bool              // Flag whether an empty block without any transaction is expected
 }
 
 type multiPackingWork struct {
@@ -46,20 +45,11 @@ type multiPackingWork struct {
 }
 
 // makeEnv creates a new environment for the sealing block.
-func (w *worker) makeEnv(parent *types.Header, header *types.Header, coinbase common.Address,
-	prevEnv *core.MinerEnvironment) (*core.MinerEnvironment, error) {
-
-	// Retrieve the parent state to execute on top and start a prefetcher for
-	// the miner to speed block sealing up a bit
+func (w *worker) makeEnv(parent *types.Header, header *types.Header, coinbase common.Address) (*core.MinerEnvironment, error) {
 	topState, err := w.chain.StateAt(parent.Root)
 	if err != nil {
 		return nil, err
 	}
-	if prevEnv == nil {
-		topState.StartPrefetcher("miner")
-	} else {
-		topState.TransferPrefetcher(prevEnv.State)
-	}
 
 	// Note the passed coinbase may be different with header.Coinbase.
 	env := &core.MinerEnvironment{
@@ -97,32 +87,17 @@ func (w *worker) commitWork(interruptCh chan int32, timestamp int64) {
 			return
 		}
 	}
-	var prevWork *core.MinerEnvironment
-	defer func() {
-		for _, wk := range workList {
-			// only keep the best work, discard others.
-			if wk.work == w.current {
-				continue
-			}
-			wk.work.Discard()
-		}
-	}()
 
 	// validator can try several times to get the most profitable block,
 	// as long as the timestamp is not reached.
 LOOP:
 	for round := 0; round < math.MaxInt64; round++ {
 		roundStart := time.Now()
 
-		work, err := w.prepareWork(&generateParams{
-			timestamp: uint64(timestamp),
-			coinbase:  coinbase,
-			prevWork:  prevWork,
-		})
+		work, err := w.prepareWork(&generateParams{timestamp: uint64(timestamp), coinbase: coinbase})
 		if err != nil {
 			return
 		}
-		prevWork = work
 		thisRound := &multiPackingWork{round: round, work: work, income: new(big.Int)}
 		workList = append(workList, thisRound)
 
@@ -243,13 +218,6 @@ LOOP:
 	bestWork := pickTheMostProfitableWork(workList)
 	_ = w.commit(bestWork.work, w.fullTaskHook, true, start)
 
-	// Swap out the old work with the new one, terminating any leftover
-	// prefetcher processes in the mean time and starting a new one.
-	if w.current != nil {
-		w.current.Discard()
-	}
-	w.current = bestWork.work
-
 	if p, ok := w.engine.(*parlia.Parlia); ok {
 		go func() {
 			tgMsg := pReporter.Finalize(blockNumber, bestWork.round, bestWork.income, p.SignText)