lucenenet-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Simon Svensson (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENENET-511) ObjectDisposedException thrown when IndexWriter disposed by finalizer
Date Tue, 02 Oct 2012 07:31:08 GMT

    [ https://issues.apache.org/jira/browse/LUCENENET-511?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13467564#comment-13467564
] 

Simon Svensson commented on LUCENENET-511:
------------------------------------------

Actually, that meant that the IndexWriter wasn't disposed by _your_ finalizer (destructor).
The garbage collection will finalize (call the destructor) the IndexWriter, but it may happen
either before or after your finalizer has executed. It's up the the nondeterministic nature
of the garbage collection to surprise us when the IndexWriter is actually finalized.

The NativeFSLock (default lock for FSDirectory) does not depend on the mere existence of the
write.lock file, it uses an exclusive lock using FileStream.Lock[1] to ensure a proper lock.
A lingering write.lock file should not cause any problems.

This wouldn't be a problem if you implemented a deterministic approach to disposing your manager,
simply by calling manager.Dispose() when closing the window. This would call Dispose(true),
and your writer will be disposed, and the lock will be "cleanly" released.

[1] http://msdn.microsoft.com/en-us/library/system.io.filestream.lock.aspx
                
> ObjectDisposedException thrown when IndexWriter disposed by finalizer
> ---------------------------------------------------------------------
>
>                 Key: LUCENENET-511
>                 URL: https://issues.apache.org/jira/browse/LUCENENET-511
>             Project: Lucene.Net
>          Issue Type: Bug
>          Components: Lucene.Net Core
>    Affects Versions: Lucene.Net 3.0.3
>         Environment: Windows 7 x64, .NET Framework 4.5
>            Reporter: Maximilian Haru Raditya
>
> 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:
> {code}
> 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;
>             }
>         }
>     }
> }
> {code}
> And the calling code looks like this:
> {code}
> 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();
>         }
>     }
> }
> {code}
> The app run just fine until I close it and it throws ObjectDisposedException as described
above.
> The exception details:
> {code}
> 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: 
> {code}

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message