Help us, please :)

We use SessionManager, so default isolation level, as I understand, is ReadCommitted.

We call one method asynchronously by ajax request, there are two simultaneous request.

And we always get deadlock. (code is simplified and "unrefactored")

  public PhotoDto AddPhoto(int id, HttpPostedFileBase file)
        var block = Session.Demand().Query.All<PhotoGalleryBlock>().FirstOrDefault(b => b.Id == id);

        var photo = new Photo
            FileName = "z"

        //after uncommenting this line there is no deadlock on #1, but it happens on #2

        var user = block.Page.Site.User;

        var blocks = user.Site.PageSet.FirstOrDefault(p => p.IsMain).BlockSet;

        var photoGalleryBlocks = blocks.OfType<PhotoGalleryBlock>();

        foreach (var photoGalleryBlock in photoGalleryBlocks)
            foreach (var photoi in photoGalleryBlock.PhotoSet)
                var x = 5;

        //DiskSpaces - Structure
        user.DiskSpaces.PhotoGallery = 5;

        return new PhotoDto(photo);


We get deadlock on foreach, trying to enumerate photoGalleryBlock.PhotoSet.

After uncommenting ### we get another deadlock on #2.

Actually, not on #2, but when transaction is completed, Sql Server throws an error "deadlock on update User set [DiskSpaces.PhotoGallery] = 5"

Thanks in advance.

asked Mar 21 '12 at 14:01

Ness's gravatar image


One Answer:

This information is not enough for catch this deadlock. You can use SQL Server Profiler with TSQL_Locks template or implement correct handling of this deadlock with reprocessing library

answered Mar 27 '12 at 11:23

proff's gravatar image


Thanks, din't know about this library.

(Mar 27 '12 at 12:04) Ness Ness's gravatar image
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