From f967e29bff4ad4fa451dbaf450772476b9d5e0e0 Mon Sep 17 00:00:00 2001
From: Julian Verdurmen <304NotModified@users.noreply.github.com>
Date: Mon, 1 May 2017 22:29:47 +0200
Subject: [PATCH] Improve performance with many threads

---
 .../LayoutRenderers/AspNetLayoutRendererBase.cs     | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/NLog.Web.AspNetCore/LayoutRenderers/AspNetLayoutRendererBase.cs b/NLog.Web.AspNetCore/LayoutRenderers/AspNetLayoutRendererBase.cs
index 64a43a1c..cf923238 100644
--- a/NLog.Web.AspNetCore/LayoutRenderers/AspNetLayoutRendererBase.cs
+++ b/NLog.Web.AspNetCore/LayoutRenderers/AspNetLayoutRendererBase.cs
@@ -38,10 +38,21 @@ protected AspNetLayoutRendererBase()
         /// <returns>HttpContextAccessor or <c>null</c></returns>
         public IHttpContextAccessor HttpContextAccessor
         {
-            get { return _httpContextAccessor ?? ServiceLocator.ServiceProvider?.GetService<IHttpContextAccessor>(); }
+            get { return _httpContextAccessor ?? (_httpContextAccessor = ServiceLocator.ServiceProvider?.GetService<IHttpContextAccessor>()); }
             set { _httpContextAccessor = value; }
         }
 
+        /// <summary>
+        ///  Initialize
+        /// </summary>
+        protected override void InitializeLayoutRenderer()
+        {
+            if (HttpContextAccessor == null)
+            {
+                Common.InternalLogger.Warn("Missing IHttpContextAccessor. Has it been registered before loading NLog Configuration? Consider reloading NLog Configuration after having registered the IHttpContextAccessor.");
+            }
+        }
+
 #else
         /// <summary>
         /// Provides access to the current request HttpContext.