some changes for more idiomatic code

nomad/rpc.go

@@ -49,9 +49,8 @@ const (
 
 type rpcHandler struct {
 	*Server
-	logger          log.Logger
-	gologger        *golog.Logger
-	acceptLoopDelay time.Duration
+	logger   log.Logger
+	gologger *golog.Logger
 }
 
 func newRpcHandler(s *Server) *rpcHandler {
@@ -85,6 +84,8 @@ type RPCContext struct {
 // listen is used to listen for incoming RPC connections
 func (r *rpcHandler) listen(ctx context.Context) {
 	defer close(r.listenerCh)
+
+	var acceptLoopDelay time.Duration
 	for {
 		select {
 		case <-ctx.Done():
@@ -99,41 +100,46 @@ func (r *rpcHandler) listen(ctx context.Context) {
 			if r.shutdown {
 				return
 			}
-			r.handleAcceptErr(err, ctx)
+			r.handleAcceptErr(ctx, err, &acceptLoopDelay)
 			continue
 		}
 		// No error, reset loop delay
-		r.acceptLoopDelay = 0
+		acceptLoopDelay = 0
 
 		go r.handleConn(ctx, conn, &RPCContext{Conn: conn})
 		metrics.IncrCounter([]string{"nomad", "rpc", "accept_conn"}, 1)
 	}
 }
 
-// Sleep to avoid spamming the log, with a maximum delay according to whether or not the error is temporary
-func (r *rpcHandler) handleAcceptErr(err error, ctx context.Context) {
-	const baseAcceptLoopDelay = 5 * time.Millisecond
-	const maxAcceptLoopDelay = 5 * time.Second
-	const maxAcceptLoopDelayTemporaryError = 1 * time.Second
+// handleAcceptErr sleeps to avoid spamming the log,
+// with a maximum delay according to whether or not the error is temporary
+func (r *rpcHandler) handleAcceptErr(ctx context.Context, err error, loopDelay *time.Duration) {
+	const baseDelay = 5 * time.Millisecond
+	const maxDelayPerm = 5 * time.Second
+	const maxDelayTemp = 1 * time.Second
 
-	if r.acceptLoopDelay == 0 {
-		r.acceptLoopDelay = baseAcceptLoopDelay
+	if *loopDelay == 0 {
+		*loopDelay = baseDelay
 	} else {
-		r.acceptLoopDelay *= 2
+		*loopDelay *= 2
 	}
+
 	temporaryError := false
 	if ne, ok := err.(net.Error); ok && ne.Temporary() {
 		temporaryError = true
 	}
-	if temporaryError && r.acceptLoopDelay > maxAcceptLoopDelayTemporaryError {
-		r.acceptLoopDelay = maxAcceptLoopDelayTemporaryError
-	} else if r.acceptLoopDelay > maxAcceptLoopDelay {
-		r.acceptLoopDelay = maxAcceptLoopDelay
+
+	if temporaryError && *loopDelay > maxDelayTemp {
+		*loopDelay = maxDelayTemp
+	} else if *loopDelay > maxDelayPerm {
+		*loopDelay = maxDelayPerm
 	}
-	r.logger.Error("failed to accept RPC conn", "error", err, "delay", r.acceptLoopDelay)
+
+	r.logger.Error("failed to accept RPC conn", "error", err, "delay", *loopDelay)
+
 	select {
 	case <-ctx.Done():
-	case <-time.After(r.acceptLoopDelay):
+	case <-time.After(*loopDelay):
 	}
 }