1 files changed, 10 insertions, 0 deletions
diff --git a/src/csharp/Grpc.Core/Internal/CompletionRegistry.cs b/src/csharp/Grpc.Core/Internal/CompletionRegistry.cs
index a4aa8d3ffe..075286d33e 100644
--- a/src/csharp/Grpc.Core/Internal/CompletionRegistry.cs
+++ b/src/csharp/Grpc.Core/Internal/CompletionRegistry.cs
@@ -52,6 +52,7 @@ namespace Grpc.Core.Internal
 
         readonly GrpcEnvironment environment;
         readonly ConcurrentDictionary<IntPtr, OpCompletionDelegate> dict = new ConcurrentDictionary<IntPtr, OpCompletionDelegate>(new IntPtrComparer());
+        IntPtr lastRegisteredKey;  // only for testing
 
         public CompletionRegistry(GrpcEnvironment environment)
         {
@@ -62,6 +63,7 @@ namespace Grpc.Core.Internal
         {
             environment.DebugStats.PendingBatchCompletions.Increment();
             GrpcPreconditions.CheckState(dict.TryAdd(key, callback));
+            this.lastRegisteredKey = key;
         }
 
         public void RegisterBatchCompletion(BatchContextSafeHandle ctx, BatchCompletionDelegate callback)
@@ -84,6 +86,14 @@ namespace Grpc.Core.Internal
             return value;
         }
 
+        /// <summary>
+        /// For testing purposes only.
+        /// </summary>
+        public IntPtr LastRegisteredKey
+        {
+            get { return this.lastRegisteredKey; }
+        }
+
         private static void HandleBatchCompletion(bool success, BatchContextSafeHandle ctx, BatchCompletionDelegate callback)
         {
             try