PR feedback

- Ensure subscribing doesn't receive out-of-order updates
- Fix log message

Author: andrewlock

tracer/src/Datadog.Trace/Configuration/DynamicConfigurationManager.cs

@@ -82,7 +82,7 @@ private static void OnConfigurationChanged(IConfigurationSource dynamicConfig, T
             var wasUpdated = tracerSettings.Manager.UpdateSettings(dynamicConfig, manualConfig, TelemetryFactory.Config);
             if (wasUpdated)
             {
-                Log.Information("Setting updates made via configuration in code were applied");
+                Log.Information("Setting updates made via dynamic configuration were applied");
             }
 
             // TODO: This might not record the config in the correct order in future, but would require

tracer/src/Datadog.Trace/Configuration/SettingsManager.cs

@@ -53,18 +53,18 @@ public IDisposable SubscribeToChanges(Action<SettingChanges> callback)
             lock (_subscribers)
             {
                 _subscribers.Add(subscription);
-            }
 
-            if (Volatile.Read(ref _latest) is { } currentConfig)
-            {
-                try
+                if (Volatile.Read(ref _latest) is { } currentConfig)
                 {
-                    // If we already have updates, call this immediately
-                    callback(currentConfig);
-                }
-                catch (Exception ex)
-                {
-                    Log.Error(ex, "Error notifying subscriber of updated MutableSettings during subscribe");
+                    try
+                    {
+                        // If we already have updates, call this immediately
+                        callback(currentConfig);
+                    }
+                    catch (Exception ex)
+                    {
+                        Log.Error(ex, "Error notifying subscriber of updated MutableSettings during subscribe");
+                    }
                 }
             }