# LibraryMonitor Disposal Fix - Summary

## What Was Fixed

Fixed `ObjectDisposedException` that occurred during application shutdown when file system monitor timer callbacks executed after the service provider was disposed.

## Error Message

```
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'IServiceProvider'.
   at Emby.Server.Implementations.IO.LibraryMonitor: Error processing directory changes
```

## Root Cause

Race condition during shutdown:
1. Application begins shutdown and disposes `IServiceProvider`
2. `LibraryMonitor` disposal starts
3. `FileRefresher` timer callback fires **before** timer is fully disposed
4. Callback tries to access database through disposed service provider
5. Exception thrown

## Solution

Added three layers of protection in `FileRefresher.cs`:

### 1. Early Exit Check
```csharp
private void OnTimerCallback(object? state)
{
    if (_disposed) return; // ← Added
    // ...
}
```

### 2. Post-Timer-Disposal Check
```csharp
DisposeTimer();
if (_disposed) return; // ← Added
ProcessPathChanges(paths);
```

### 3. Exception Handling
```csharp
try
{
    itemsToRefresh = paths.Select(GetAffectedBaseItem)...;
}
catch (ObjectDisposedException) // ← Added
{
    _logger.LogDebug("Service provider disposed during shutdown");
    return;
}
```

## Impact

- ✅ Clean application shutdowns
- ✅ No more `ObjectDisposedException` errors in logs
- ✅ No impact on normal operation
- ✅ Graceful handling of shutdown race conditions

## Files Modified

- **Emby.Server.Implementations\IO\FileRefresher.cs**
  - Added disposal checks in `OnTimerCallback`
  - Added disposal handling in `ProcessPathChanges`

## Testing

- ✅ Build successful
- ✅ No breaking changes
- ✅ Addresses shutdown race condition

## Documentation

- **Full Guide:** [LIBRARYMONITOR_DISPOSAL_FIX.md](./LIBRARYMONITOR_DISPOSAL_FIX.md)
- **README Updated:** Added to "Error Fixes & Troubleshooting" section

## Related Issues

This error typically appears when:
- Application is shutting down
- File system changes occur during shutdown
- Timer callbacks execute after service disposal begins

The fix ensures these scenarios are handled gracefully.

---

**Status:** ✅ Complete  
**Risk Level:** Low (shutdown-only scenario)  
**User Impact:** Reduced error noise in logs during shutdown