GPO tracks down correctly. Also GPO can be set to always offer zero i… (ethereum#94)

* GPO tracks down correctly. Also GPO can be set to always offer zero if miner.gasprice=0

* Rename GPO param floor -> defaultPrice

Author: timmoreton

build/bin/geth.aar

@@ -359,7 +359,7 @@ func doTest(cmdline []string) {
 	// Test a single package at a time. CI builders are slow
 	// and some tests run into timeouts under load.
 	gotest := goTool("test", buildFlags(env)...)
-	gotest.Args = append(gotest.Args, "-p", "1", "-timeout", "5m")
+	gotest.Args = append(gotest.Args, "-p", "1", "-timeout", "5m", "-v")
 	if *coverage {
 		gotest.Args = append(gotest.Args, "-covermode=atomic", "-cover")
 	}

build/ci.go

@@ -625,22 +625,22 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 	}
 	// If the transaction fails basic validation, discard it
 	if err := pool.validateTx(tx, local); err != nil {
-		log.Trace("Discarding invalid transaction", "hash", hash, "err", err)
+		log.Debug("Discarding invalid transaction", "hash", hash, "err", err)
 		invalidTxCounter.Inc(1)
 		return false, err
 	}
 	// If the transaction pool is full, discard underpriced transactions
 	if uint64(pool.all.Count()) >= pool.config.GlobalSlots+pool.config.GlobalQueue {
 		// If the new transaction is underpriced, don't accept it
 		if !local && pool.priced.Underpriced(tx, pool.locals) {
-			log.Trace("Discarding underpriced transaction", "hash", hash, "price", tx.GasPrice())
+			log.Debug("Discarding underpriced transaction", "hash", hash, "price", tx.GasPrice())
 			underpricedTxCounter.Inc(1)
 			return false, ErrUnderpriced
 		}
 		// New transaction is better than our worse ones, make room for it
 		drop := pool.priced.Discard(pool.all.Count()-int(pool.config.GlobalSlots+pool.config.GlobalQueue-1), pool.locals)
 		for _, tx := range drop {
-			log.Trace("Discarding freshly underpriced transaction", "hash", tx.Hash(), "price", tx.GasPrice())
+			log.Debug("Discarding freshly underpriced transaction", "hash", tx.Hash(), "price", tx.GasPrice())
 			underpricedTxCounter.Inc(1)
 			pool.removeTx(tx.Hash(), false)
 		}

core/tx_pool.go

@@ -49,14 +49,15 @@ var DefaultConfig = Config{
 	TrieTimeout:                 60 * time.Minute,
 	MinerGasFloor:               8000000,
 	MinerGasCeil:                8000000,
-	MinerGasPrice:               big.NewInt(0), // params.GWei
+	MinerGasPrice:               big.NewInt(0), // Always free gas
 	MinerRecommit:               3 * time.Second,
 	MinerVerificationServiceUrl: "https://mining-pool.celo.org/v0.1/sms",
 
 	TxPool: core.DefaultTxPoolConfig,
 	GPO: gasprice.Config{
 		Blocks:     20,
 		Percentile: 60,
+		AlwaysZero: true, // Always free gas
 	},
 }
 

eth/config.go

@@ -35,6 +35,7 @@ type Config struct {
 	Blocks     int
 	Percentile int
 	Default    *big.Int `toml:",omitempty"`
+	AlwaysZero bool
 }
 
 // Oracle recommends gas prices based on the content of recent
@@ -48,6 +49,8 @@ type Oracle struct {
 
 	checkBlocks, maxEmpty, maxBlocks int
 	percentile                       int
+	defaultPrice                     *big.Int
+	alwaysZero                       bool
 }
 
 // NewOracle returns a new oracle.
@@ -64,17 +67,24 @@ func NewOracle(backend ethapi.Backend, params Config) *Oracle {
 		percent = 100
 	}
 	return &Oracle{
-		backend:     backend,
-		lastPrice:   params.Default,
-		checkBlocks: blocks,
-		maxEmpty:    blocks / 2,
-		maxBlocks:   blocks * 5,
-		percentile:  percent,
+		backend:      backend,
+		lastPrice:    params.Default,
+		checkBlocks:  blocks,
+		maxEmpty:     blocks / 2,
+		maxBlocks:    blocks * 5,
+		percentile:   percent,
+		defaultPrice: params.Default,
+		alwaysZero:   params.AlwaysZero,
 	}
 }
 
 // SuggestPrice returns the recommended gas price.
 func (gpo *Oracle) SuggestPrice(ctx context.Context) (*big.Int, error) {
+
+	if gpo.alwaysZero {
+		return big.NewInt(0), nil
+	}
+
 	gpo.cacheLock.RLock()
 	lastHead := gpo.lastHead
 	lastPrice := gpo.lastPrice
@@ -131,7 +141,7 @@ func (gpo *Oracle) SuggestPrice(ctx context.Context) (*big.Int, error) {
 			blockNum--
 		}
 	}
-	price := lastPrice
+	price := gpo.defaultPrice
 	if len(blockPrices) > 0 {
 		sort.Sort(bigIntArray(blockPrices))
 		price = blockPrices[(len(blockPrices)-1)*gpo.percentile/100]

eth/gasprice/gasprice.go

@@ -47,7 +47,7 @@ import (
 )
 
 const (
-	defaultGasPrice = params.GWei
+	defaultGasPrice = uint64(0) // Always free gas
 )
 
 // PublicEthereumAPI provides an API to access Ethereum related information.