Fix InvalidOp when enumerating the SystemClockChanged hashset

dotnet · Apr 8, 2019 · c889767 · c889767
1 parent 04d98ea
commit c889767
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/Rx.NET/Source/src/System.Reactive/Internal/SystemClock.cs b/Rx.NET/Source/src/System.Reactive/Internal/SystemClock.cs
@@ -59,7 +59,9 @@ private static void OnSystemClockChanged(object sender, SystemClockChangedEventA
         {
             lock (SystemClockChanged)
             {
-                foreach (var entry in SystemClockChanged)
+                // create a defensive copy as the callbacks may change the hashset
+                var copySystemClockChanged = new List<WeakReference<LocalScheduler>>(SystemClockChanged);
+                foreach (var entry in copySystemClockChanged)
                 {
                     if (entry.TryGetTarget(out var scheduler))
                     {