[jira] [Comment Edited] (LUCENENET-511) ObjectDisposedException thrown when IndexWriter disposed by finalizer

["Simon Svensson (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LUCENENET-511?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13467532#comment-13467532 ] 

Simon Svensson edited comment on LUCENENET-511 at 10/2/12 5:43 PM:
-------------------------------------------------------------------

Your code does not properly implement the IDisposable pattern. See http://msdn.microsoft.com/en-us/library/system.idisposable.aspx for an example, the Dispose(Boolean) method should only dispose of managed resources when the parameter is true.  The problem is caused since garbage collection is nondeterministic; the order of destructor calls are _not guaranteed_.

{code}
    if (isDisposing) {
        if (_indexWriter != null) {
            _indexWriter.Dispose();
            _indexWriter = null;
        }
    }
{/code}
                
      was (Author: sisve):
    Your code does not properly implement the IDisposable pattern. See http://msdn.microsoft.com/en-us/library/system.idisposable.aspx for an example, the Dispose(Boolean) method should only dispose of managed resources when the parameter is true.  The problem is caused since garbage collection is nondeterministic; the order of destructor calls are _not guaranteed_.

{code}
if (isDisposing) {
    if (_indexWriter != null) {
        _indexWriter.Dispose();
        _indexWriter = null;
    }
}
{/code}
                  
> 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