ratelimiter: fixing rate limiter use

Use of the ratelimiter should be conscious of the ratelimiter's
potential closing. any loops that add work to ratelimiter
should (a) only do so if the rate limiter is not closed,
or (b) prevent limiter while work is added
(i.e. use limiter.Go(addWorkHere))

net/swarm/swarm_dial.go

@@ -385,20 +385,23 @@ func (s *Swarm) dialAddrs(ctx context.Context, d *conn.Dialer, p peer.ID, remote
 	go func() {
 		// rate limiting just in case. at most 10 addrs at once.
 		limiter := ratelimit.NewRateLimiter(procctx.WithContext(ctx), 10)
-
-		// permute addrs so we try different sets first each time.
-		for _, i := range rand.Perm(len(remoteAddrs)) {
-			select {
-			case <-foundConn: // if one of them succeeded already
-				break
-			default:
+		limiter.Go(func(worker process.Process) {
+			// permute addrs so we try different sets first each time.
+			for _, i := range rand.Perm(len(remoteAddrs)) {
+				select {
+				case <-foundConn: // if one of them succeeded already
+					break
+				case <-worker.Closing(): // our context was cancelled
+					break
+				default:
+				}
+
+				workerAddr := remoteAddrs[i] // shadow variable to avoid race
+				limiter.LimitedGo(func(worker process.Process) {
+					dialSingleAddr(workerAddr)
+				})
 			}
-
-			workerAddr := remoteAddrs[i] // shadow variable to avoid race
-			limiter.Go(func(worker process.Process) {
-				dialSingleAddr(workerAddr)
-			})
-		}
+		})
 	}()
 
 	// wair fot the results.