From bc92dc631cebd9e5253648427935ccad47203836 Mon Sep 17 00:00:00 2001
From: parallelbgls <parallelbgls@outlook.com>
Date: Thu, 4 Jan 2018 14:18:45 +0800
Subject: [PATCH] Fix

---
 Modbus.Net/Modbus.Net/FifoController.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Modbus.Net/Modbus.Net/FifoController.cs b/Modbus.Net/Modbus.Net/FifoController.cs
index 6535461..4bcf679 100644
--- a/Modbus.Net/Modbus.Net/FifoController.cs
+++ b/Modbus.Net/Modbus.Net/FifoController.cs
@@ -116,7 +116,12 @@ namespace Modbus.Net
         /// <inheritdoc />
         protected override MessageWaitingDef GetMessageFromWaitingList(byte[] receiveMessage)
         {
-            return WaitingMessages.FirstOrDefault();
+            MessageWaitingDef ans;
+            lock (WaitingMessages)
+            {
+                ans = WaitingMessages.FirstOrDefault();
+            }
+            return ans;
         }
 
         /// <inheritdoc />