NLogLoggingConfiguration - Fix memory-leak when using AutoReload

NLog · Aug 24, 2024 · c3db743 · c3db743
1 parent c2875ea
commit c3db743
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Showing 2 changed files with 28 additions and 1 deletion.
diff --git a/src/NLog.Extensions.Logging/Config/NLogLoggingConfiguration.cs b/src/NLog.Extensions.Logging/Config/NLogLoggingConfiguration.cs
@@ -59,6 +59,7 @@ public override IEnumerable<string> FileNamesToWatch
                 {
                     // Prepare for setting up reload notification handling
                     _reloadConfiguration = state => ReloadConfigurationSection((IConfigurationSection)state);
+                    LogFactory.ConfigurationChanged -= LogFactory_ConfigurationChanged; // Avoid double registration
                     LogFactory.ConfigurationChanged += LogFactory_ConfigurationChanged;
                 }
 
@@ -102,6 +103,7 @@ private void LogFactory_ConfigurationChanged(object sender, LoggingConfiguration
             else if (ReferenceEquals(e.ActivatedConfiguration, this) && _autoReload && _reloadConfiguration != null)
             {
                 // Setup reload notification
+                LogFactory.ConfigurationChanged -= LogFactory_ConfigurationChanged; // Avoid double registration
                 LogFactory.ConfigurationChanged += LogFactory_ConfigurationChanged;
                 MonitorForReload(_originalConfigSection);
             }

diff --git a/test/NLog.Extensions.Logging.Tests/NLogLoggingConfigurationTests.cs b/test/NLog.Extensions.Logging.Tests/NLogLoggingConfigurationTests.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -386,6 +387,30 @@ public void ReloadLogFactoryConfiguration()
             configuration.Reload(); // Nothing should happen
         }
 
+        [Fact]
+        public void ReloadLogFactoryConfigurationWithoutLeak()
+        {
+            var memoryConfig = CreateMemoryConfigConsoleTargetAndRule();
+            memoryConfig["NLog:Targets:file:type"] = "File";
+            memoryConfig["NLog:Targets:file:fileName"] = "hello.txt";
+            memoryConfig["NLog:AutoReload"] = "true";
+            var logFactory = new LogFactory();
+            var newConfig = CreateConfiguration(logFactory, memoryConfig);
+            logFactory.Configuration = null;
+            GC.Collect();
+            Assert.False(newConfig.TryGetTarget(out _));
+        }
+
+        static WeakReference<NLogLoggingConfiguration> CreateConfiguration(LogFactory logFactory, IEnumerable<KeyValuePair<string, string>> config)
+        {
+            var configuration = new ConfigurationBuilder().AddInMemoryCollection(config).Build();
+            var nlogConfig = new NLogLoggingConfiguration(configuration.GetSection("NLog"), logFactory);
+            logFactory.Configuration = nlogConfig;
+            configuration.Reload();
+            (configuration as IDisposable)?.Dispose();
+            return new WeakReference<NLogLoggingConfiguration>(nlogConfig);
+        }
+
         [Fact]
         public void ReloadLogFactoryConfigurationKeepVariables()
         {