[LUCENENET-511] ObjectDisposedException thrown when IndexWriter disposed by finalizer

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: Lucene.Net 3.0.3
• Component/s: Lucene.Net Core

Environment

Windows 7 x64, .NET Framework 4.5

• Assignee: Unassigned
• Reporter: Maximilian Haru Raditya
• Created: 02/Oct/12 02:40
• Updated: 03/Nov/12 00:19
• Resolved: 03/Nov/12 00:19

Description

I'm having an issue of ObjectDisposedException with an error message "Cannot access a closed file." when working IndexWriter.

I manage to reproduce it when I create a new WPF (4.5) app and install 3.0.3-RC2 from NuGet. I then create a LuceneManager which implements IDisposable, and I create a finalizer for it. I wrap IndexWriter inside it, and dispose it inside Dispose(bool). The implementation code looks like this:

namespace WpfApplication
{
    using System;
    using System.Collections.Generic;
    using System.IO;

    using Lucene.Net.Analysis.Standard;
    using Lucene.Net.Index;
    using Lucene.Net.Store;

    using Version = Lucene.Net.Util.Version;

    public class LuceneManager : IDisposable
    {
        public static readonly string IndexPath =
            Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Index");

        private IndexWriter _indexWriter;

        private bool _isDisposed;

        public LuceneManager()
        {
            var directory = FSDirectory.Open(IndexPath);
            var analyzer = new StandardAnalyzer(Version.LUCENE_30, new HashSet<string>());
            this._indexWriter = new IndexWriter(directory, analyzer, IndexWriter.MaxFieldLength.UNLIMITED);
        }

        ~LuceneManager()
        {
            this.Dispose(false);
        }

        public void Dispose()
        {
            this.Dispose(true);
            GC.SuppressFinalize(this);
        }

        private void Dispose(bool isDisposing)
        {
            if (!this._isDisposed)
            {
                if (this._indexWriter != null)
                {
                    this._indexWriter.Dispose();
                }
                this._indexWriter = null;

                this._isDisposed = true;
            }
        }
    }
}

And the calling code looks like this:

namespace WpfApplication
{
    using System.Windows;

    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();
        }

        private void OnLoaded(object sender, RoutedEventArgs e)
        {
            var lucenceManager = new LuceneManager();
        }
    }
}

The app run just fine until I close it and it throws ObjectDisposedException as described above.

The exception details:

System.ObjectDisposedException was unhandled
  HResult=-2146232798
  Message=Cannot access a closed file.
  Source=mscorlib
  ObjectName=""
  StackTrace:
       at System.IO.__Error.FileNotOpen()
       at System.IO.FileStream.get_Length()
       at Lucene.Net.Store.NativeFSLock.Release()
       at Lucene.Net.Index.IndexWriter.CloseInternal(Boolean waitForMerges)
       at Lucene.Net.Index.IndexWriter.Dispose(Boolean disposing, Boolean waitForMerges)
       at Lucene.Net.Index.IndexWriter.Dispose(Boolean waitForMerges)
       at Lucene.Net.Index.IndexWriter.Dispose()
       at WpfApplication.LuceneManager.Dispose(Boolean isDisposing)
       at WpfApplication.LuceneManager.Finalize()
  InnerException: