From 30d79c7b316ae5cc7ba590bf6537e684e4a8216b Mon Sep 17 00:00:00 2001
From: Igor Milavec <igor.milavec@gmail.com>
Date: Sun, 28 Nov 2021 15:42:04 +0100
Subject: [PATCH] Start MessageListener with
 ThreadAbstraction.ExecuteThreadLongRunning (#902)

* Fix Thread pool exhaustion due to MessageListener running on ThreadPool
* Mark long running thread as background
---
 src/Renci.SshNet/Abstractions/ThreadAbstraction.cs | 9 +++++++--
 src/Renci.SshNet/Session.cs                        | 3 ++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/Renci.SshNet/Abstractions/ThreadAbstraction.cs b/src/Renci.SshNet/Abstractions/ThreadAbstraction.cs
index ee21ec7ef..8c344404b 100644
--- a/src/Renci.SshNet/Abstractions/ThreadAbstraction.cs
+++ b/src/Renci.SshNet/Abstractions/ThreadAbstraction.cs
@@ -21,12 +21,17 @@ public static void Sleep(int millisecondsTimeout)
 
         public static void ExecuteThreadLongRunning(Action action)
         {
+            if (action == null)
+                throw new ArgumentNullException("action");
+
 #if FEATURE_THREAD_TAP
             var taskCreationOptions = System.Threading.Tasks.TaskCreationOptions.LongRunning;
             System.Threading.Tasks.Task.Factory.StartNew(action, taskCreationOptions);
 #else
-            var thread = new System.Threading.Thread(() => action());
-            thread.Start();
+            new System.Threading.Thread(() => action())
+            {
+                IsBackground = true
+            }.Start();
 #endif
         }
 
diff --git a/src/Renci.SshNet/Session.cs b/src/Renci.SshNet/Session.cs
index 0748b8dac..d2bf4bdf1 100644
--- a/src/Renci.SshNet/Session.cs
+++ b/src/Renci.SshNet/Session.cs
@@ -618,7 +618,8 @@ public void Connect()
                     _messageListenerCompleted.Reset();
 
                     // Start incoming request listener
-                    ThreadAbstraction.ExecuteThread(() => MessageListener());
+                    // ToDo: Make message pump async, to not consume a thread for every session
+                    ThreadAbstraction.ExecuteThreadLongRunning(() => MessageListener());
 
                     // Wait for key exchange to be completed
                     WaitOnHandle(_keyExchangeCompletedWaitHandle);