PR feedback

Author: JamesNK

src/Shared/Diagnostics/ActivityCreator.cs

@@ -58,8 +58,8 @@ internal static class ActivityCreator
                 // Can only happen if there is a race between HasListeners and CreateActivity calls,
                 // and someone removing the listener.
                 //
-                // The only negative of calling the propagator twice is a small performance hit, but
-                // it's small and unlikely so it's not worth trying to optimize.
+                // The only negative of calling the propagator twice is a small performance hit.
+                // It's small and unlikely so it's not worth trying to optimize.
                 propagator.ExtractTraceIdAndState(
                     distributedContextCarrier,
                     propagatorGetter,

src/SignalR/server/Core/src/Internal/DefaultHubDispatcher.cs

@@ -857,11 +857,11 @@ public override IReadOnlyList<Type> GetParameterTypes(string methodName)
         ];
         IEnumerable<ActivityLink>? links = (linkedActivity is not null) ? [new ActivityLink(linkedActivity.Context)] : null;
 
-        var propagator = serviceProvider.GetService<DistributedContextPropagator>() ?? DistributedContextPropagator.Current;
-
         Activity? activity;
         if (headers != null)
         {
+            var propagator = serviceProvider.GetService<DistributedContextPropagator>() ?? DistributedContextPropagator.Current;
+
             activity = ActivityCreator.CreateFromRemote(
                 activitySource,
                 propagator,