refactor: use go ticker instead of timer

ethdb/leveldb/leveldb.go

@@ -326,8 +326,8 @@ func (db *Database) meter(refresh time.Duration, namespace string) {
 		delaystats      [2]int64
 		lastWritePaused time.Time
 	)
-	timer := time.NewTimer(refresh)
-	defer timer.Stop()
+	ticker := time.NewTicker(refresh)
+	defer ticker.Stop()
 
 	// Iterate ad infinitum and collect the stats
 	for i := 1; errc == nil && merr == nil; i++ {
@@ -411,8 +411,7 @@ func (db *Database) meter(refresh time.Duration, namespace string) {
 		select {
 		case errc = <-db.quitChan:
 			// Quit requesting, stop hammering the database
-		case <-timer.C:
-			timer.Reset(refresh)
+		case <-ticker.C:
 			// Timeout, gather a new set of stats
 		}
 	}

ethdb/pebble/pebble.go

@@ -452,8 +452,8 @@ func (d *Database) Path() string {
 // the metrics subsystem.
 func (d *Database) meter(refresh time.Duration, namespace string) {
 	var errc chan error
-	timer := time.NewTimer(refresh)
-	defer timer.Stop()
+	ticker := time.NewTicker(refresh)
+	defer ticker.Stop()
 
 	// Create storage and warning log tracer for write delay.
 	var (
@@ -550,8 +550,7 @@ func (d *Database) meter(refresh time.Duration, namespace string) {
 		select {
 		case errc = <-d.quitChan:
 			// Quit requesting, stop hammering the database
-		case <-timer.C:
-			timer.Reset(refresh)
+		case <-ticker.C:
 			// Timeout, gather a new set of stats
 		}
 	}

p2p/peer.go

@@ -297,7 +297,7 @@ loop:
 func (p *Peer) pingLoop() {
 	defer p.wg.Done()
 
-	ping := time.NewTimer(pingInterval)
+	ping := time.NewTicker(pingInterval)
 	defer ping.Stop()
 
 	for {
@@ -307,7 +307,6 @@ func (p *Peer) pingLoop() {
 				p.protoErr <- err
 				return
 			}
-			ping.Reset(pingInterval)
 
 		case <-p.pingRecv:
 			SendItems(p.rw, pongMsg)