XmlLoggingConfiguration - Protect against double dispose of AutoReloadConfigFileWatcher

snakefoot · snakefoot · commit 8bf70224dfc7 · 2025-09-27T09:09:51.000+02:00
diff --git a/src/NLog/Config/XmlLoggingConfiguration.cs b/src/NLog/Config/XmlLoggingConfiguration.cs
@@ -256,7 +256,7 @@ protected internal override void OnConfigurationAssigned(LogFactory? logFactory)
 
                 if (logFactory is null || !AutoReload)
                 {
-                    if (fileWatcher != null)
+                    if (fileWatcher != null && !fileWatcher.IsDisposed)
                     {
                         InternalLogger.Info("AutoReload Config File Monitor stopping, since no active configuration");
                         fileWatcher.Dispose();
@@ -661,11 +661,8 @@ private void ReloadTimer(object state)
                     }
 
                     var currentTimer = _reloadTimer;
-                    if (currentTimer != null)
-                    {
-                        _reloadTimer = null;
-                        currentTimer.Dispose();
-                    }
+                    _reloadTimer = null;
+                    currentTimer?.Dispose();
                 }
 
                 LoggingConfiguration? newConfig = null;
@@ -708,7 +705,6 @@ private void ReloadTimer(object state)
                 {
                     InternalLogger.Warn(exception, "AutoReload Config File Monitor failed to activate new NLog LoggingConfiguration.");
                     _fileWatcher.Watch((oldConfig as XmlLoggingConfiguration)?.AutoReloadFileNames ?? ArrayHelper.Empty<string>());
-
                 }
             }
 
@@ -719,14 +715,19 @@ public void RefreshFileWatcher(IEnumerable<string> fileNamesToWatch)
 
             public void Dispose()
             {
-                _isDisposing = true;
-                _fileWatcher.FileChanged -= FileWatcher_FileChanged;
+                var reloadTimer = _reloadTimer;
                 lock (_lockObject)
                 {
-                    var reloadTimer = _reloadTimer;
+                    if (_isDisposing)
+                        return;
+
+                    reloadTimer = _reloadTimer;
+                    _isDisposing = true;
                     _reloadTimer = null;
-                    reloadTimer?.Dispose();
                 }
+
+                _fileWatcher.FileChanged -= FileWatcher_FileChanged;
+                reloadTimer?.Dispose();
                 _fileWatcher.Dispose();
             }
 

Original file line number	Diff line number	Diff line change
`@@ -256,7 +256,7 @@ protected internal override void OnConfigurationAssigned(LogFactory? logFactory)`
`256`	`256`
`257`	`257`	`if (logFactory is null \|\| !AutoReload)`
`258`	`258`	`{`
`259`		`- if (fileWatcher != null)`
	`259`	`+ if (fileWatcher != null && !fileWatcher.IsDisposed)`
`260`	`260`	`{`
`261`	`261`	`InternalLogger.Info("AutoReload Config File Monitor stopping, since no active configuration");`
`262`	`262`	`fileWatcher.Dispose();`
`@@ -661,11 +661,8 @@ private void ReloadTimer(object state)`
`661`	`661`	`}`
`662`	`662`
`663`	`663`	`var currentTimer = _reloadTimer;`
`664`		`- if (currentTimer != null)`
`665`		`- {`
`666`		`- _reloadTimer = null;`
`667`		`- currentTimer.Dispose();`
`668`		`- }`
	`664`	`+ _reloadTimer = null;`
	`665`	`+ currentTimer?.Dispose();`
`669`	`666`	`}`
`670`	`667`
`671`	`668`	`LoggingConfiguration? newConfig = null;`
`@@ -708,7 +705,6 @@ private void ReloadTimer(object state)`
`708`	`705`	`{`
`709`	`706`	`InternalLogger.Warn(exception, "AutoReload Config File Monitor failed to activate new NLog LoggingConfiguration.");`
`710`	`707`	`_fileWatcher.Watch((oldConfig as XmlLoggingConfiguration)?.AutoReloadFileNames ?? ArrayHelper.Empty<string>());`
`711`		`-`
`712`	`708`	`}`
`713`	`709`	`}`
`714`	`710`
`@@ -719,14 +715,19 @@ public void RefreshFileWatcher(IEnumerable<string> fileNamesToWatch)`
`719`	`715`
`720`	`716`	`public void Dispose()`
`721`	`717`	`{`
`722`		`- _isDisposing = true;`
`723`		`- _fileWatcher.FileChanged -= FileWatcher_FileChanged;`
	`718`	`+ var reloadTimer = _reloadTimer;`
`724`	`719`	`lock (_lockObject)`
`725`	`720`	`{`
`726`		`- var reloadTimer = _reloadTimer;`
	`721`	`+ if (_isDisposing)`
	`722`	`+ return;`
	`723`	`+`
	`724`	`+ reloadTimer = _reloadTimer;`
	`725`	`+ _isDisposing = true;`
`727`	`726`	`_reloadTimer = null;`
`728`		`- reloadTimer?.Dispose();`
`729`	`727`	`}`
	`728`	`+`
	`729`	`+ _fileWatcher.FileChanged -= FileWatcher_FileChanged;`
	`730`	`+ reloadTimer?.Dispose();`
`730`	`731`	`_fileWatcher.Dispose();`
`731`	`732`	`}`
`732`	`733`