From e58ebfa6b4cf967880f12e378de7176dcf616187 Mon Sep 17 00:00:00 2001
From: Paul Higinbotham <paulhi@microsoft.com>
Date: Fri, 20 Dec 2019 13:20:10 -0800
Subject: [PATCH] Fix race condition exception on recent change to OutOfProc
 transport (#11406)

---
 .../fanin/OutOfProcTransportManager.cs        | 50 ++++++++++++++-----
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
index c94f5a7461..baef84419a 100644
--- a/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
+++ b/src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
@@ -628,7 +628,29 @@ namespace System.Management.Automation.Remoting.Client
             {
                 _cmdTransportManagers.Clear();
                 _closeTimeOutTimer.Dispose();
+
+                // Stop session processing thread.
+                try
+                {
+                    _sessionMessageQueue.CompleteAdding();
+                }
+                catch (ObjectDisposedException)
+                {
+                    // Object already disposed.
+                }
+
                 _sessionMessageQueue.Dispose();
+
+                // Stop command processing thread.
+                try
+                {
+                    _commandMessageQueue.CompleteAdding();
+                }
+                catch (ObjectDisposedException)
+                {
+                    // Object already disposed.
+                }
+                
                 _commandMessageQueue.Dispose();
             }
         }
@@ -683,10 +705,6 @@ namespace System.Management.Automation.Remoting.Client
             // stop timer
             _closeTimeOutTimer.Change(Timeout.Infinite, Timeout.Infinite);
 
-            // Stop protocol message processing threads.
-            _sessionMessageQueue.CompleteAdding();
-            _commandMessageQueue.CompleteAdding();
-
             RaiseCloseCompleted();
             CleanupConnection();
         }
@@ -753,17 +771,25 @@ namespace System.Management.Automation.Remoting.Client
 
         protected void HandleOutputDataReceived(string data)
         {
-            // Route protocol message based on whether it is a session or command message.
-            // Session messages have empty Guid values.
-            if (Guid.Equals(GetMessageGuid(data), Guid.Empty))
+            try
             {
-                // Session message
-                _sessionMessageQueue.Add(data);
+                // Route protocol message based on whether it is a session or command message.
+                // Session messages have empty Guid values.
+                if (Guid.Equals(GetMessageGuid(data), Guid.Empty))
+                {
+                    // Session message
+                    _sessionMessageQueue.Add(data);
+                }
+                else
+                {
+                    // Command message
+                    _commandMessageQueue.Add(data);
+                }
             }
-            else
+            catch (InvalidOperationException)
             {
-                // Command message
-                _commandMessageQueue.Add(data);
+                // This exception will be thrown by the BlockingCollection message queue objects
+                // after they have been closed.
             }
         }