add NewTxPoolHeadEvent

5 files changed, 28 insertions, 5 deletions

diff --git a/core/events.go b/core/events.go
index 09e9180..aa58d08 100644
--- a/core/events.go
+++ b/core/events.go
@@ -24,6 +24,9 @@ import (
 // NewTxsEvent is posted when a batch of transactions enter the transaction pool.
 type NewTxsEvent struct{ Txs []*types.Transaction }
 
+// NewTxPoolHeadEvent is posted when the pool head is updated.
+type NewTxPoolHeadEvent struct{ block *types.Block }
+
 // PendingLogsEvent is posted pre mining and notifies of pending logs.
 type PendingLogsEvent struct {
 	Logs []*types.Log
diff --git a/core/tx_pool.go b/core/tx_pool.go
index caabd5c..3454936 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -213,6 +213,7 @@ type TxPool struct {
 	chain       blockChain
 	gasPrice    *big.Int
 	txFeed      event.Feed
+	headFeed    event.Feed
 	scope       event.SubscriptionScope
 	signer      types.Signer
 	mu          sync.RWMutex
@@ -328,6 +329,7 @@ func (pool *TxPool) loop() {
 			if ev.Block != nil {
 				pool.requestReset(head.Header(), ev.Block.Header())
 				head = ev.Block
+				pool.headFeed.Send(NewTxPoolHeadEvent{head})
 			}
 
 		// System shutdown.
@@ -398,6 +400,12 @@ func (pool *TxPool) SubscribeNewTxsEvent(ch chan<- NewTxsEvent) event.Subscripti
 	return pool.scope.Track(pool.txFeed.Subscribe(ch))
 }
 
+// SubscribeNewHeadEvent registers a subscription of NewHeadEvent and
+// starts sending event to the given channel.
+func (pool *TxPool) SubscribeNewHeadEvent(ch chan<- NewTxPoolHeadEvent) event.Subscription {
+	return pool.scope.Track(pool.headFeed.Subscribe(ch))
+}
+
 // GasPrice returns the current gas price enforced by the transaction pool.
 func (pool *TxPool) GasPrice() *big.Int {
 	pool.mu.RLock()
diff --git a/coreth.go b/coreth.go
index ca2a5de..8cc5f77 100644
--- a/coreth.go
+++ b/coreth.go
@@ -7,6 +7,7 @@ import (
 	"os"
 
 	"github.com/ava-labs/coreth/consensus/dummy"
+	"github.com/ava-labs/coreth/core"
 	"github.com/ava-labs/coreth/eth"
 	"github.com/ava-labs/coreth/miner"
 	"github.com/ava-labs/coreth/node"
@@ -180,10 +181,15 @@ func (self *ETHChain) AttachEthService(handler *rpc.Server, namespaces []string)
 	}
 }
 
+// TODO: use SubscribeNewTxsEvent()
 func (self *ETHChain) GetTxSubmitCh() <-chan struct{} {
 	return self.backend.GetTxSubmitCh()
 }
 
+func (self *ETHChain) GetTxPool() *core.TxPool {
+	return self.backend.TxPool()
+}
+
 type Key struct {
 	Address    common.Address
 	PrivateKey *ecdsa.PrivateKey
diff --git a/examples/counter/main.go b/examples/counter/main.go
index e802a33..86e839a 100644
--- a/examples/counter/main.go
+++ b/examples/counter/main.go
@@ -6,11 +6,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/ava-labs/coreth"
+	"github.com/ava-labs/coreth/core"
 	"github.com/ava-labs/coreth/eth"
 	"github.com/ava-labs/go-ethereum/common"
 	"github.com/ava-labs/go-ethereum/common/compiler"
-	//"github.com/ava-labs/go-ethereum/common/hexutil"
-	"github.com/ava-labs/go-ethereum/core"
 	"github.com/ava-labs/go-ethereum/core/types"
 	"github.com/ava-labs/go-ethereum/crypto"
 	"github.com/ava-labs/go-ethereum/log"
@@ -94,6 +93,7 @@ func main() {
 
 	blockCount := 0
 	chain := coreth.NewETHChain(&config, nil, nil, nil)
+	newTxPoolHeadChan := make(chan core.NewTxPoolHeadEvent, 1)
 	log.Info(chain.GetGenesisBlock().Hash().Hex())
 	firstBlock := false
 	var contractAddr common.Address
@@ -145,11 +145,15 @@ func main() {
 		if postGen(block) {
 			return nil
 		}
-		chain.GenBlock()
+		go func() {
+			<-newTxPoolHeadChan
+			chain.GenBlock()
+		}()
 		return nil
 	})
 
 	// start the chain
+	chain.GetTxPool().SubscribeNewHeadEvent(newTxPoolHeadChan)
 	chain.Start()
 
 	_ = contract
diff --git a/examples/payments/main.go b/examples/payments/main.go
index 1eab70b..5076737 100644
--- a/examples/payments/main.go
+++ b/examples/payments/main.go
@@ -4,10 +4,10 @@ import (
 	"crypto/rand"
 	"fmt"
 	"github.com/ava-labs/coreth"
+	"github.com/ava-labs/coreth/core"
 	"github.com/ava-labs/coreth/eth"
 	"github.com/ava-labs/go-ethereum/common"
 	"github.com/ava-labs/go-ethereum/common/hexutil"
-	"github.com/ava-labs/go-ethereum/core"
 	"github.com/ava-labs/go-ethereum/core/types"
 	"github.com/ava-labs/go-ethereum/log"
 	"github.com/ava-labs/go-ethereum/params"
@@ -83,11 +83,13 @@ func main() {
 		header.Extra = append(header.Extra, hid...)
 	})
 	newBlockChan := make(chan *types.Block)
+	newTxPoolHeadChan := make(chan core.NewTxPoolHeadEvent, 1)
 	chain.SetOnSealFinish(func(block *types.Block) error {
 		newBlockChan <- block
 		return nil
 	})
 
+	chain.GetTxPool().SubscribeNewHeadEvent(newTxPoolHeadChan)
 	// start the chain
 	chain.Start()
 	for i := 0; i < 42; i++ {
@@ -98,7 +100,7 @@ func main() {
 		nonce++
 		chain.GenBlock()
 		block := <-newBlockChan
-		chain.SetTail(block.Hash())
+		<-newTxPoolHeadChan
 		log.Info("finished generating block, starting the next iteration", "height", block.Number())
 	}
 	showBalance()