From 24a1e878396086e16c156d465528a75480e521bf Mon Sep 17 00:00:00 2001
From: Sparronator9999 <86388887+Sparronator9999@users.noreply.github.com>
Date: Tue, 31 Dec 2024 14:25:44 +1100
Subject: [PATCH] Fix performance regression in IPC library from race condition
 fix

---
 YAMDCC.IPC/NamedPipeConnection.cs | 9 +++++++--
 YAMDCC.IPC/YAMDCC.IPC.csproj      | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/YAMDCC.IPC/NamedPipeConnection.cs b/YAMDCC.IPC/NamedPipeConnection.cs
index 0c77d40..b1a1911 100644
--- a/YAMDCC.IPC/NamedPipeConnection.cs
+++ b/YAMDCC.IPC/NamedPipeConnection.cs
@@ -2,6 +2,7 @@
 using System.Collections.Concurrent;
 using System.IO.Pipes;
 using System.Runtime.InteropServices;
+using System.Threading;
 using YAMDCC.IPC.IO;
 using YAMDCC.IPC.Threading;
 
@@ -57,6 +58,7 @@ public class NamedPipeConnection<TRead, TWrite> : IDisposable
 
         private readonly PipeStreamWrapper<TRead, TWrite> _streamWrapper;
 
+        private readonly AutoResetEvent _writeSignal = new(false);
         private readonly BlockingCollection<TWrite> _writeQueue = new();
 
         private bool _notifiedSucceeded;
@@ -82,7 +84,7 @@ internal NamedPipeConnection(int id, string name, PipeStream serverStream)
         /// </param>
         public bool PushMessage(TWrite message)
         {
-            return _writeQueue.TryAdd(message);
+            return _writeQueue.TryAdd(message) && _writeSignal.Set();
         }
 
         /// <summary>
@@ -116,6 +118,7 @@ internal void Close()
         {
             _streamWrapper.Close();
             _writeQueue.CompleteAdding();
+            _writeSignal.Set();
         }
 
         /// <summary>
@@ -169,7 +172,8 @@ private void WritePipe()
         {
             while (IsConnected && _streamWrapper.CanWrite)
             {
-                if (_writeQueue.TryTake(out TWrite obj))
+                _writeSignal.WaitOne();
+                while (_writeQueue.TryTake(out TWrite obj) || _writeQueue.Count > 0)
                 {
                     _streamWrapper.WriteObject(obj);
                     _streamWrapper.WaitForPipeDrain();
@@ -193,6 +197,7 @@ private void Dispose(bool disposing)
             if (disposing)
             {
                 Close();
+                _writeSignal.Dispose();
                 _writeQueue.Dispose();
             }
 
diff --git a/YAMDCC.IPC/YAMDCC.IPC.csproj b/YAMDCC.IPC/YAMDCC.IPC.csproj
index 10e2374..8d9348b 100644
--- a/YAMDCC.IPC/YAMDCC.IPC.csproj
+++ b/YAMDCC.IPC/YAMDCC.IPC.csproj
@@ -12,7 +12,7 @@
         <RuntimeIdentifiers>win7-x64;win7-x86;win-x64;win-x86</RuntimeIdentifiers>
         <TargetFramework>net48</TargetFramework>
         <Title>Named Pipe Wrapper library</Title>
-        <VersionPrefix>2.1.1</VersionPrefix>
+        <VersionPrefix>2.1.2</VersionPrefix>
         <VersionSuffix>release</VersionSuffix>
     </PropertyGroup>
     <PropertyGroup Condition="'$(Configuration)'=='Release'">