From 4337d2a4a751ee7ccb0e0c460670c0abd044d040 Mon Sep 17 00:00:00 2001
From: Stephen Halter <halter73@gmail.com>
Date: Thu, 28 Jul 2016 16:02:30 -0700
Subject: [PATCH] Implement Begin/End Read/Write methods in LibuvStream

---
 .../Filter/Internal/LibuvStream.cs            | 78 +++++++++++++++++++
 .../Filter/Internal/StreamSocketOutput.cs     | 47 +++--------
 2 files changed, 90 insertions(+), 35 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/LibuvStream.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/LibuvStream.cs
index 3ae1ddbd69..0127d156a0 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/LibuvStream.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/LibuvStream.cs
@@ -132,5 +132,83 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Filter.Internal
         {
             return _input.ReadAsync(buffer.Array, buffer.Offset, buffer.Count);
         }
+
+#if NET451
+        public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
+        {
+            var task = ReadAsync(buffer, offset, count, default(CancellationToken), state);
+            if (callback != null)
+            {
+                task.ContinueWith(t => callback.Invoke(t));
+            }
+            return task;
+        }
+
+        public override int EndRead(IAsyncResult asyncResult)
+        {
+            return ((Task<int>)asyncResult).GetAwaiter().GetResult();
+        }
+
+        private Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken, object state)
+        {
+            var tcs = new TaskCompletionSource<int>(state);
+            var task = ReadAsync(buffer, offset, count, cancellationToken);
+            task.ContinueWith((task2, state2) =>
+            {
+                var tcs2 = (TaskCompletionSource<int>)state2;
+                if (task2.IsCanceled)
+                {
+                    tcs2.SetCanceled();
+                }
+                else if (task2.IsFaulted)
+                {
+                    tcs2.SetException(task2.Exception);
+                }
+                else
+                {
+                    tcs2.SetResult(task2.Result);
+                }
+            }, tcs, cancellationToken);
+            return tcs.Task;
+        }
+
+        public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
+        {
+            var task = WriteAsync(buffer, offset, count, default(CancellationToken), state);
+            if (callback != null)
+            {
+                task.ContinueWith(t => callback.Invoke(t));
+            }
+            return task;
+        }
+
+        public override void EndWrite(IAsyncResult asyncResult)
+        {
+            ((Task<object>)asyncResult).GetAwaiter().GetResult();
+        }
+
+        private Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken, object state)
+        {
+            var tcs = new TaskCompletionSource<object>(state);
+            var task = WriteAsync(buffer, offset, count, cancellationToken);
+            task.ContinueWith((task2, state2) =>
+            {
+                var tcs2 = (TaskCompletionSource<object>)state2;
+                if (task2.IsCanceled)
+                {
+                    tcs2.SetCanceled();
+                }
+                else if (task2.IsFaulted)
+                {
+                    tcs2.SetException(task2.Exception);
+                }
+                else
+                {
+                    tcs2.SetResult(null);
+                }
+            }, tcs, cancellationToken);
+            return tcs.Task;
+        }
+#endif
     }
 }
diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/StreamSocketOutput.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/StreamSocketOutput.cs
index bfd7d5201b..52397633fc 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/StreamSocketOutput.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Filter/Internal/StreamSocketOutput.cs
@@ -24,8 +24,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Filter.Internal
 
         private bool _canWrite = true;
 
-        private object _writeLock = new object();
-
         public StreamSocketOutput(string connectionId, Stream outputStream, MemoryPool memory, IKestrelTrace logger)
         {
             _connectionId = connectionId;
@@ -36,54 +34,33 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Filter.Internal
 
         public void Write(ArraySegment<byte> buffer, bool chunk)
         {
-            lock (_writeLock)
+            if (buffer.Count == 0 )
             {
-                if (buffer.Count == 0 )
-                {
-                    return;
-                }
+                return;
+            }
 
-                try
-                {
-                    if (!_canWrite)
-                    {
-                        return;
-                    }
+            if (chunk && buffer.Array != null)
+            {
+                var beginChunkBytes = ChunkWriter.BeginChunkBytes(buffer.Count);
+                _outputStream.Write(beginChunkBytes.Array, beginChunkBytes.Offset, beginChunkBytes.Count);
+            }
 
-                    if (chunk && buffer.Array != null)
-                    {
-                        var beginChunkBytes = ChunkWriter.BeginChunkBytes(buffer.Count);
-                        _outputStream.Write(beginChunkBytes.Array, beginChunkBytes.Offset, beginChunkBytes.Count);
-                    }
+            _outputStream.Write(buffer.Array ?? _nullBuffer, buffer.Offset, buffer.Count);
 
-                    _outputStream.Write(buffer.Array ?? _nullBuffer, buffer.Offset, buffer.Count);
-
-                    if (chunk && buffer.Array != null)
-                    {
-                        _outputStream.Write(_endChunkBytes, 0, _endChunkBytes.Length);
-                    }
-                }
-                catch (Exception ex)
-                {
-                    _canWrite = false;
-                    _logger.ConnectionError(_connectionId, ex);
-                }
+            if (chunk && buffer.Array != null)
+            {
+                _outputStream.Write(_endChunkBytes, 0, _endChunkBytes.Length);
             }
         }
 
         public Task WriteAsync(ArraySegment<byte> buffer, bool chunk, CancellationToken cancellationToken)
         {
-#if NET451
-            Write(buffer, chunk);
-            return TaskUtilities.CompletedTask;
-#else
             if (chunk && buffer.Array != null)
             {
                 return WriteAsyncChunked(buffer, cancellationToken);
             }
 
             return _outputStream.WriteAsync(buffer.Array ?? _nullBuffer, buffer.Offset, buffer.Count, cancellationToken);
-#endif
         }
 
         private async Task WriteAsyncChunked(ArraySegment<byte> buffer, CancellationToken cancellationToken)