1 files changed, 30 insertions, 9 deletions

diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
index d3a2be553f..171d0c799d 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
@@ -43,7 +43,7 @@ using Grpc.Core.Utils;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// Handles server side native call lifecycle.
+    /// Manages server side native call lifecycle.
     /// </summary>
     internal class AsyncCallServer<TRequest, TResponse> : AsyncCallBase<TResponse, TRequest>
     {
@@ -57,24 +57,22 @@ namespace Grpc.Core.Internal
 
         public void Initialize(CallSafeHandle call)
         {
+            DebugStats.ActiveServerCalls.Increment();
             InitializeInternal(call);
         }
 
         /// <summary>
-        /// Starts a server side call. Currently, all server side calls are implemented as duplex 
-        /// streaming call and they are adapted to the appropriate streaming arity.
+        /// Starts a server side call.
         /// </summary>
-        public Task ServerSideCallAsync(IObserver<TRequest> readObserver)
+        public Task ServerSideCallAsync()
         {
             lock (myLock)
             {
                 Preconditions.CheckNotNull(call);
 
                 started = true;
-                this.readObserver = readObserver;
 
                 call.StartServerSide(finishedServersideHandler);
-                StartReceiveMessage();
                 return finishedServersideTcs.Task;
             }
         }
@@ -83,17 +81,26 @@ namespace Grpc.Core.Internal
         /// Sends a streaming response. Only one pending send action is allowed at any given time.
         /// completionDelegate is called when the operation finishes.
         /// </summary>
-        public void StartSendMessage(TResponse msg, AsyncCompletionDelegate completionDelegate)
+        public void StartSendMessage(TResponse msg, AsyncCompletionDelegate<object> completionDelegate)
         {
             StartSendMessageInternal(msg, completionDelegate);
         }
 
         /// <summary>
+        /// Receives a streaming request. Only one pending read action is allowed at any given time.
+        /// completionDelegate is called when the operation finishes.
+        /// </summary>
+        public void StartReadMessage(AsyncCompletionDelegate<TRequest> completionDelegate)
+        {
+            StartReadMessageInternal(completionDelegate);
+        }
+
+        /// <summary>
         /// Sends call result status, also indicating server is done with streaming responses.
         /// Only one pending send action is allowed at any given time.
         /// completionDelegate is called when the operation finishes.
         /// </summary>
-        public void StartSendStatusFromServer(Status status, AsyncCompletionDelegate completionDelegate)
+        public void StartSendStatusFromServer(Status status, AsyncCompletionDelegate<object> completionDelegate)
         {
             lock (myLock)
             {
@@ -106,18 +113,32 @@ namespace Grpc.Core.Internal
             }
         }
 
+        protected override void OnReleaseResources()
+        {
+            DebugStats.ActiveServerCalls.Decrement();
+        }
+
         /// <summary>
         /// Handles the server side close completion.
         /// </summary>
         private void HandleFinishedServerside(bool wasError, BatchContextSafeHandleNotOwned ctx)
         {
+            bool cancelled = ctx.GetReceivedCloseOnServerCancelled();
+
             lock (myLock)
             {
                 finished = true;
 
+                if (cancelled)
+                {
+                    // Once we cancel, we don't have to care that much 
+                    // about reads and writes.
+                    Cancel();
+                }
+
                 ReleaseResourcesIfPossible();
             }
-            // TODO: handle error ...
+            // TODO(jtattermusch): handle error
 
             finishedServersideTcs.SetResult(null);
         }