core: using testing.B.Loop (#32662)

Co-authored-by: lightclient <[email protected]>

Author: cuiweixie

core/bench_test.go

@@ -301,7 +301,7 @@ func makeChainForBench(db ethdb.Database, genesis *Genesis, full bool, count uin
 
 func benchWriteChain(b *testing.B, full bool, count uint64) {
 	genesis := &Genesis{Config: params.AllEthashProtocolChanges}
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		pdb, err := pebble.New(b.TempDir(), 1024, 128, "", false)
 		if err != nil {
 			b.Fatalf("error opening database: %v", err)
@@ -326,9 +326,7 @@ func benchReadChain(b *testing.B, full bool, count uint64) {
 	db.Close()
 	options := DefaultConfig().WithArchive(true)
 	b.ReportAllocs()
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		pdb, err = pebble.New(dir, 1024, 128, "", false)
 		if err != nil {
 			b.Fatalf("error opening database: %v", err)

core/rlp_test.go

@@ -149,8 +149,7 @@ func BenchmarkHashing(b *testing.B) {
 	var got common.Hash
 	var hasher = sha3.NewLegacyKeccak256()
 	b.Run("iteratorhashing", func(b *testing.B) {
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			var hash common.Hash
 			it, err := rlp.NewListIterator(bodyRlp)
 			if err != nil {
@@ -172,8 +171,7 @@ func BenchmarkHashing(b *testing.B) {
 	})
 	var exp common.Hash
 	b.Run("fullbodyhashing", func(b *testing.B) {
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			var body types.Body
 			rlp.DecodeBytes(bodyRlp, &body)
 			for _, tx := range body.Transactions {
@@ -182,8 +180,7 @@ func BenchmarkHashing(b *testing.B) {
 		}
 	})
 	b.Run("fullblockhashing", func(b *testing.B) {
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			var block types.Block
 			rlp.DecodeBytes(blockRlp, &block)
 			for _, tx := range block.Transactions() {