From a4b8b01c997bf9da8854743ae8d9b994fbc7f2c4 Mon Sep 17 00:00:00 2001
From: Stephen Halter <halter73@gmail.com>
Date: Mon, 25 Jan 2016 11:02:24 -0800
Subject: [PATCH] Remove immediate parameter from Frame.ProduceStart

- Simply call SocketOutput.WriteAsync(_emptyData) to force headers to be flushed
---
 .../Http/Frame.FeatureCollection.cs           |  5 +-
 .../Http/Frame.cs                             | 47 ++++++++-----------
 2 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.FeatureCollection.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.FeatureCollection.cs
index 8a10a7c618..f93f88915d 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.FeatureCollection.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.FeatureCollection.cs
@@ -312,7 +312,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                 }
             }
 
-            await ProduceStartAndFireOnStarting(immediate: true); 
+            await ProduceStartAndFireOnStarting();
+
+            // Force flush
+            await SocketOutput.WriteAsync(_emptyData);
 
             return DuplexStream;
         }
diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.cs
index 4c1d096e6f..7272329639 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Http/Frame.cs
@@ -392,19 +392,19 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
 
         public void Flush()
         {
-            ProduceStartAndFireOnStarting(immediate: false).GetAwaiter().GetResult();
+            ProduceStartAndFireOnStarting().GetAwaiter().GetResult();
             SocketOutput.Write(_emptyData);
         }
 
         public async Task FlushAsync(CancellationToken cancellationToken)
         {
-            await ProduceStartAndFireOnStarting(immediate: false);
+            await ProduceStartAndFireOnStarting();
             await SocketOutput.WriteAsync(_emptyData, cancellationToken: cancellationToken);
         }
 
         public void Write(ArraySegment<byte> data)
         {
-            ProduceStartAndFireOnStarting(immediate: false).GetAwaiter().GetResult();
+            ProduceStartAndFireOnStarting().GetAwaiter().GetResult();
 
             if (_autoChunk)
             {
@@ -443,7 +443,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
 
         public async Task WriteAsyncAwaited(ArraySegment<byte> data, CancellationToken cancellationToken)
         {
-            await ProduceStartAndFireOnStarting(immediate: false);
+            await ProduceStartAndFireOnStarting();
 
             if (_autoChunk)
             {
@@ -493,13 +493,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
             }
         }
 
-        public Task ProduceStartAndFireOnStarting(bool immediate)
+        public Task ProduceStartAndFireOnStarting()
         {
             if (_responseStarted) return TaskUtilities.CompletedTask;
 
             if (_onStarting != null)
             {
-                return FireOnStartingProduceStart(immediate);
+                return ProduceStartAndFireOnStartingAwaited();
             }
 
             if (_applicationException != null)
@@ -509,10 +509,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                     _applicationException);
             }
 
-            return ProduceStart(immediate, appCompleted: false);
+            ProduceStart(appCompleted: false);
+
+            return TaskUtilities.CompletedTask;
         }
 
-        private async Task FireOnStartingProduceStart(bool immediate)
+        private async Task ProduceStartAndFireOnStartingAwaited()
         {
             await FireOnStarting();
 
@@ -523,17 +525,17 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                     _applicationException);
             }
 
-            await ProduceStart(immediate, appCompleted: false);
+            ProduceStart(appCompleted: false);
         }
 
-        private Task ProduceStart(bool immediate, bool appCompleted)
+        private void ProduceStart(bool appCompleted)
         {
-            if (_responseStarted) return TaskUtilities.CompletedTask;
+            if (_responseStarted) return;
             _responseStarted = true;
 
             var statusBytes = ReasonPhrases.ToStatusBytes(StatusCode, ReasonPhrase);
 
-            return CreateResponseHeader(statusBytes, appCompleted, immediate);
+            CreateResponseHeader(statusBytes, appCompleted);
         }
 
         protected Task ProduceEnd()
@@ -556,7 +558,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                 }
             }
 
-
             if (!_responseStarted)
             {
                 return ProduceEndAwaited();
@@ -567,7 +568,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
 
         private async Task ProduceEndAwaited()
         {
-            await ProduceStart(immediate: true, appCompleted: true);
+            ProduceStart(appCompleted: true);
+
+            // Force flush
+            await SocketOutput.WriteAsync(_emptyData);
 
             await WriteSuffix();
         }
@@ -599,10 +603,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
             }
         }
 
-        private Task CreateResponseHeader(
+        private void CreateResponseHeader(
             byte[] statusBytes,
-            bool appCompleted,
-            bool immediate)
+            bool appCompleted)
         {
             var end = SocketOutput.ProducingStart();
             if (_keepAlive)
@@ -658,16 +661,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
             end.CopyFrom(_bytesEndHeaders, 0, _bytesEndHeaders.Length);
 
             SocketOutput.ProducingComplete(end);
-
-            if (immediate)
-            {
-                // Force a call to uv_write
-                return SocketOutput.WriteAsync(default(ArraySegment<byte>));
-            }
-            else
-            {
-                return TaskUtilities.CompletedTask;
-            }
         }
 
         protected bool TakeStartLine(SocketInput input)