Comments on: SPLimitedWebPartManager Memory Leak?

By: bryan

bryan — Fri, 18 Nov 2011 13:45:00 +0000

Ah, you’re right Adrian! When I looked earlier I just took a quick glance at Dispose() and noticed it still wasn’t cleaning it up, but you’re right, it’s no longer creating the instance inside of SPLimitedWebPartManager, instead it’s point to an instance created by SPWebPartManager, and SPWebPartManager cleans up the SPWeb object.

Thanks for the correction!

By: Adrian Iurov

Adrian Iurov — Fri, 18 Nov 2011 13:31:44 +0000

From what I’ve seen in the code, this is NOT a memory leak in SP2010.

These 2 fields are part of the SPLimitedWebPartManager class:

SPWeb m_web;
SPWebPartManager m_manager;

When Dispose() is called on SPLimitedWebPartManager, inside it calls m_manager.Dispose() which calls m_web.Dipose()

The m_web of the SPWebPartManager instance references the same SPWeb instance as the m_web of the SPLimitedWebPartManager instance.

In order to see that the 2 fields reference the same SPWeb instance, take a look at the way this m_web is opened inside SPWeb.GetLimitedWebPartManagerInternal. Later on is assigned to the m_web of a SPWebPartCollectionInitialState instance and in the end to the newly created SPWebPartManager instance.

It’s a bit hard to follow, but if you need more details about the entire flow, I could provide them to you.

By: bryan

bryan — Tue, 01 Nov 2011 15:32:50 +0000

From what I’ve seen, yes. I poked around in SPLimitedWebPartManager for 2010 and it still does not appear to close the SPWeb object that it opens up, so I would recommend still explicitly closing it. If anyone has seen differently in 2010 let me know!

By: Tudor Iliescu

Tudor Iliescu — Tue, 01 Nov 2011 10:44:38 +0000

Very interesting! It the same in 2010?

By: ArianaSype

ArianaSype — Wed, 13 May 2009 12:18:32 +0000

Wow! Thank you very much! I always wanted to write in my site something like that

By: JessicaRich

JessicaRich — Sun, 10 May 2009 17:20:29 +0000

Thanks for posting, definitely going to subscribe! See you on my reader.

By: Incanna

Incanna — Fri, 08 May 2009 05:37:35 +0000

ehh. interesting..

By: admin

admin — Wed, 24 Oct 2007 12:38:43 +0000

The difference is that the web part manager is not using your w instance, it creates its own instance on the following line:

SPWeb web = this.Site.OpenWeb();

In your example you actually have 2 instances of SPWeb, you have your instance “w”, and then there is an instance encapsulated in the web part manager “web”. The web part manager should dispose of the “web” instance, not your “w” instance.

By: Shai

Shai — Wed, 24 Oct 2007 11:07:59 +0000

Hi,
I fail to understand why you feel that disposing of the web part manager should also dispose its owner web?

for instance, if you have code like this:
spweb w = …..
SPLimitedWebPartManager mgr = w.OpenFile(“…”).GetLimitedWebPartManager(…);
mgr.AddWebPart(…);
mgr.Dispose();

w.Title += ” Done!”;
w.Update();
w.Dispose();

See, I continue to work on the web object after disposing of the limited web part manager… It would be a bug if my w.TItle update will fail… no?

By: Peter {faa780ce-0f0a-4c28-81d2-3667b71287fd}

Peter {faa780ce-0f0a-4c28-81d2-3667b71287fd} — Fri, 28 Sep 2007 19:15:20 +0000

Yes, this is exactly what I saw. It didn’t surprise me at all when I got my “outofmemoryexception”; I already had a healthy fear of SharePoint.