chore: replace polling with subscription-based acceptance

tests/load2/main/main.go

@@ -115,7 +115,7 @@ func main() {
 		chainID,
 		metricsNamespace,
 		registry,
-		load2.ZeroTransferTest{PollFrequency: pollFrequency},
+		load2.ZeroTransferTest{},
 	)
 	require.NoError(err)
 

tests/load2/tests.go

@@ -6,7 +6,6 @@ package load2
 import (
 	"context"
 	"math/big"
-	"time"
 
 	"github.com/ava-labs/libevm/common"
 	"github.com/ava-labs/libevm/core/types"
@@ -19,11 +18,9 @@ import (
 
 var _ Test = (*ZeroTransferTest)(nil)
 
-type ZeroTransferTest struct {
-	PollFrequency time.Duration
-}
+type ZeroTransferTest struct{}
 
-func (z ZeroTransferTest) Run(
+func (ZeroTransferTest) Run(
 	tc tests.TestContext,
 	ctx context.Context,
 	wallet *Wallet,
@@ -48,5 +45,5 @@ func (z ZeroTransferTest) Run(
 	})
 	require.NoError(err)
 
-	require.NoError(wallet.SendTx(ctx, tx, z.PollFrequency))
+	require.NoError(wallet.SendTx(ctx, tx))
 }

tests/load2/wallet.go

@@ -6,16 +6,14 @@ package load2
 import (
 	"context"
 	"crypto/ecdsa"
-	"errors"
 	"fmt"
 	"math/big"
 	"time"
 
 	"github.com/ava-labs/libevm/common"
 	"github.com/ava-labs/libevm/core/types"
+	"github.com/ava-labs/libevm/crypto"
 	"github.com/ava-labs/libevm/ethclient"
-
-	ethereum "github.com/ava-labs/libevm"
 )
 
 type Wallet struct {
@@ -47,8 +45,22 @@ func newWallet(
 func (w *Wallet) SendTx(
 	ctx context.Context,
 	tx *types.Transaction,
-	pingFrequency time.Duration,
 ) error {
+	// start listening for blocks
+	headers := make(chan *types.Header)
+	sub, err := w.client.SubscribeNewHead(ctx, headers)
+	if err != nil {
+		return err
+	}
+
+	defer func() {
+		sub.Unsubscribe()
+
+		// wait for err chan to close before safely closing headers
+		<-sub.Err()
+		close(headers)
+	}()
+
 	startTime := time.Now()
 	if err := w.client.SendTransaction(ctx, tx); err != nil {
 		return err
@@ -57,7 +69,13 @@ func (w *Wallet) SendTx(
 	issuanceDuration := time.Since(startTime)
 	w.metrics.issue(issuanceDuration)
 
-	if err := awaitTx(ctx, w.client, tx.Hash(), pingFrequency); err != nil {
+	err = w.awaitTx(
+		ctx,
+		headers,
+		sub.Err(),
+		tx.Hash(),
+	)
+	if err != nil {
 		return err
 	}
 
@@ -70,32 +88,41 @@ func (w *Wallet) SendTx(
 	return nil
 }
 
-func awaitTx(
+func (w Wallet) awaitTx(
 	ctx context.Context,
-	client *ethclient.Client,
+	headers chan *types.Header,
+	errs <-chan error,
 	txHash common.Hash,
-	pingFrequency time.Duration,
 ) error {
-	ticker := time.NewTicker(pingFrequency)
-	defer ticker.Stop()
-
+	account := crypto.PubkeyToAddress(w.privKey.PublicKey)
 	for {
-		receipt, err := client.TransactionReceipt(ctx, txHash)
-		if err == nil {
-			if receipt.Status != types.ReceiptStatusSuccessful {
-				return fmt.Errorf("failed tx: %d", receipt.Status)
-			}
-			return nil
-		}
-
-		if !errors.Is(err, ethereum.NotFound) {
-			return err
-		}
-
 		select {
 		case <-ctx.Done():
 			return ctx.Err()
-		case <-ticker.C:
+		case err := <-errs:
+			return err
+		case h := <-headers:
+			latestNonce, err := w.client.NonceAt(
+				ctx,
+				account,
+				h.Number,
+			)
+			if err != nil {
+				return err
+			}
+
+			if latestNonce == w.nonce+1 {
+				receipt, err := w.client.TransactionReceipt(ctx, txHash)
+				if err != nil {
+					return err
+				}
+
+				if receipt.Status != types.ReceiptStatusSuccessful {
+					return fmt.Errorf("failed tx: %d", receipt.Status)
+				}
+
+				return nil
+			}
 		}
 	}
 }