From 94cd29ea76e26393cf074f0e7251abd2a3f064d8 Mon Sep 17 00:00:00 2001
From: Jason Brooks <jason.brooks@smokeball.com>
Date: Fri, 8 Nov 2024 15:45:10 +1100
Subject: [PATCH] Ensure synchronous handling does not block new requests and
 allow clearing SyncInfoCache

---
 src/ServiceWire/StreamingChannel.cs |  5 ++
 src/ServiceWire/TcpIp/TcpHost.cs    | 89 +++++++++++++++++------------
 2 files changed, 56 insertions(+), 38 deletions(-)

diff --git a/src/ServiceWire/StreamingChannel.cs b/src/ServiceWire/StreamingChannel.cs
index 6f7c6d2..de3ad51 100644
--- a/src/ServiceWire/StreamingChannel.cs
+++ b/src/ServiceWire/StreamingChannel.cs
@@ -28,6 +28,11 @@ public StreamingChannel(ISerializer serializer, ICompressor compressor)
             _parameterTransferHelper = new ParameterTransferHelper(_serializer, _compressor);
         }
 
+        public static void ClearCachedSyncInfo()
+        {
+            SyncInfoCache.Clear();
+        }
+
         protected virtual IChannelIdentifier ChannelIdentifier { get; }
 
         /// <summary>
diff --git a/src/ServiceWire/TcpIp/TcpHost.cs b/src/ServiceWire/TcpIp/TcpHost.cs
index 5b7015f..ead07d9 100644
--- a/src/ServiceWire/TcpIp/TcpHost.cs
+++ b/src/ServiceWire/TcpIp/TcpHost.cs
@@ -94,9 +94,11 @@ private void Listen()
                     _acceptEventArg.AcceptSocket = null;
                     try
                     {
+                        // If AcceptAsync returns false - it must be handled synchronously.
+                        // https://learn.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.acceptasync#system-net-sockets-socket-acceptasync(system-net-sockets-socketasynceventargs)
                         if (!_listener.AcceptAsync(_acceptEventArg))
                         {
-                            AcceptNewClient(_acceptEventArg);
+                            AcceptNewClient(_acceptEventArg, true);
                         }
                     }
                     catch (Exception ex)
@@ -117,10 +119,10 @@ private void Listen()
 
         private void acceptEventArg_Completed(object sender, SocketAsyncEventArgs e)
         {
-            AcceptNewClient(e);
+            AcceptNewClient(e, false);
         }
 
-        private void AcceptNewClient(SocketAsyncEventArgs e)
+        private void AcceptNewClient(SocketAsyncEventArgs e, bool processRequestsOnTask)
         {
             try
             {
@@ -130,54 +132,65 @@ private void AcceptNewClient(SocketAsyncEventArgs e)
                     return;
                 }
 
-                Socket activeSocket = null;
-                BufferedStream stream = null;
-                try
-                {
-                    activeSocket = e.AcceptSocket;
+                Socket activeSocket = e.AcceptSocket;
 
-                    // Signal the listening thread to continue.
-                    _listenResetEvent.Set();
+                // Signal the listening thread to continue.
+                _listenResetEvent.Set();
 
-                    stream = new BufferedStream(new NetworkStream(activeSocket), 8192);
-                    base.ProcessRequest(stream);
+                if (processRequestsOnTask)
+                {
+                    Task.Factory.StartNew(() => StartProcessingRequestsOnSocket(activeSocket), TaskCreationOptions.LongRunning);
+                }
+                else
+                {
+                    StartProcessingRequestsOnSocket(activeSocket);
                 }
-                catch (Exception ex)
+            }
+            catch (Exception fatalException)
+            {
+                _log.Fatal("AcceptNewClient fatal error: {0}", fatalException.ToString().Flatten());
+            }
+        }
+
+        private void StartProcessingRequestsOnSocket(Socket activeSocket)
+        {
+            BufferedStream stream = null;
+            try
+            {
+                stream = new BufferedStream(new NetworkStream(activeSocket), 8192);
+                base.ProcessRequest(stream);
+            }
+            catch (Exception ex)
+            {
+                _log.Error("AcceptNewClient_ProcessRequest error: {0}", ex.ToString().Flatten());
+            }
+            finally
+            {
+                if (null != stream)
                 {
-                    _log.Error("AcceptNewClient_ProcessRequest error: {0}", ex.ToString().Flatten());
+                    stream.Close();
                 }
-                finally
+                if (null != activeSocket && activeSocket.Connected)
                 {
-                    if (null != stream)
+                    try
                     {
-                        stream.Close();
+                        activeSocket.Shutdown(SocketShutdown.Both);
                     }
-                    if (null != activeSocket && activeSocket.Connected)
+                    catch (Exception shutdownException)
                     {
-                        try
-                        {
-                            activeSocket.Shutdown(SocketShutdown.Both);
-                        }
-                        catch (Exception shutdownException)
-                        {
-                            _log.Error("AcceptNewClient_ActiveSocketShutdown error: {0}", shutdownException.ToString().Flatten());
-                        }
+                        _log.Error("AcceptNewClient_ActiveSocketShutdown error: {0}", shutdownException.ToString().Flatten());
+                    }
 
-                        try
-                        {
-                            activeSocket.Close();
-                        }
-                        catch (Exception closeException)
-                        {
-                            _log.Error("AcceptNewClient_ActiveSocketClose error: {0}", closeException.ToString().Flatten());
-                        }
+                    try
+                    {
+                        activeSocket.Close();
+                    }
+                    catch (Exception closeException)
+                    {
+                        _log.Error("AcceptNewClient_ActiveSocketClose error: {0}", closeException.ToString().Flatten());
                     }
                 }
             }
-            catch (Exception fatalException)
-            {
-                _log.Fatal("AcceptNewClient fatal error: {0}", fatalException.ToString().Flatten());
-            }
         }
 
         #region IDisposable Members