1 files changed, 78 insertions, 2 deletions
diff --git a/csharp/ProtocolBuffers/IRpcController.cs b/csharp/ProtocolBuffers/IRpcController.cs
index 81348fde..f4e29ad4 100644
--- a/csharp/ProtocolBuffers/IRpcController.cs
+++ b/csharp/ProtocolBuffers/IRpcController.cs
@@ -1,8 +1,84 @@
 using System;
-using System.Collections.Generic;
-using System.Text;
 
 namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Mediates a single method call. The primary purpose of the controller
+  /// is to provide a way to manipulate settings specific to the
+  /// RPC implementation and to find out about RPC-level errors.
+  /// 
+  /// The methods provided by this interface are intended to be a "least
+  /// common denominator" set of features which we expect all implementations to
+  /// support. Specific implementations may provide more advanced features,
+  /// (e.g. deadline propagation).
+  /// </summary>
   public interface IRpcController {
+
+    #region Client side calls
+    // These calls may be made from the client side only.  Their results
+    // are undefined on the server side (may throw exceptions).
+
+    /// <summary>
+    /// Resets the controller to its initial state so that it may be reused in
+    /// a new call.  This can be called from the client side only.  It must not
+    /// be called while an RPC is in progress.
+    /// </summary>
+    void Reset();
+
+    /// <summary>
+    /// After a call has finished, returns true if the call failed.  The possible
+    /// reasons for failure depend on the RPC implementation. Failed must
+    /// only be called on the client side, and must not be called before a call has
+    /// finished.
+    /// </summary>
+    bool Failed { get; }
+
+    /// <summary>
+    /// If Failed is true, ErrorText returns a human-readable description of the error.
+    /// </summary>
+    string ErrorText { get; }
+
+    /// <summary>
+    /// Advises the RPC system that the caller desires that the RPC call be
+    /// canceled. The RPC system may cancel it immediately, may wait awhile and
+    /// then cancel it, or may not even cancel the call at all. If the call is
+    /// canceled, the "done" callback will still be called and the RpcController
+    /// will indicate that the call failed at that time.
+    /// </summary>
+    void StartCancel();
+    #endregion
+
+    #region Server side calls
+    // These calls may be made from the server side only.  Their results
+    // are undefined on the client side (may throw exceptions).
+
+    /// <summary>
+    /// Causes Failed to return true on the client side. <paramref name="reason"/>
+    /// will be incorporated into the message returned by ErrorText.
+    /// If you find you need to return machine-readable information about
+    /// failures, you should incorporate it into your response protocol buffer
+    /// and should *not* call SetFailed.
+    /// </summary>
+    void SetFailed(string reason);
+
+    /// <summary>
+    /// If true, indicates that the client canceled the RPC, so the server may as
+    /// well give up on replying to it. This method must be called on the server
+    /// side only. The server should still call the final "done" callback.
+    /// </summary>
+    bool isCanceled();
+
+    /// <summary>
+    /// Requests that the given callback be called when the RPC is canceled.
+    /// The parameter passed to the callback will always be null. The callback will
+    /// be called exactly once. If the RPC completes without being canceled, the
+    /// callback will be called after completion. If the RPC has already been canceled
+    /// when NotifyOnCancel is called, the callback will be called immediately.
+    /// 
+    /// NotifyOnCancel must be called no more than once per request. It must be
+    /// called on the server side only.
+    /// </summary>
+    /// <param name="callback"></param>
+    void NotifyOnCancel(Action<object> callback);
+    #endregion
   }
 }