1 files changed, 16 insertions, 2 deletions
diff --git a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
index 0979de606f..e75108c7e5 100644
--- a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
@@ -32,7 +32,6 @@
 #endregion
 
 using System;
-using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 
 namespace Grpc.Core
@@ -40,18 +39,22 @@ namespace Grpc.Core
     /// <summary>
     /// Return type for bidirectional streaming calls.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this call.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this call.</typeparam>
     public sealed class AsyncDuplexStreamingCall<TRequest, TResponse> : IDisposable
     {
         readonly IClientStreamWriter<TRequest> requestStream;
         readonly IAsyncStreamReader<TResponse> responseStream;
+        readonly Task<Metadata> responseHeadersAsync;
         readonly Func<Status> getStatusFunc;
         readonly Func<Metadata> getTrailersFunc;
         readonly Action disposeAction;
 
-        public AsyncDuplexStreamingCall(IClientStreamWriter<TRequest> requestStream, IAsyncStreamReader<TResponse> responseStream, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
+        internal AsyncDuplexStreamingCall(IClientStreamWriter<TRequest> requestStream, IAsyncStreamReader<TResponse> responseStream, Task<Metadata> responseHeadersAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
         {
             this.requestStream = requestStream;
             this.responseStream = responseStream;
+            this.responseHeadersAsync = responseHeadersAsync;
             this.getStatusFunc = getStatusFunc;
             this.getTrailersFunc = getTrailersFunc;
             this.disposeAction = disposeAction;
@@ -80,6 +83,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.responseHeadersAsync;
+            }
+        }
+
+        /// <summary>
         /// Gets the call status if the call has already finished.
         /// Throws InvalidOperationException otherwise.
         /// </summary>