DevTeach 2009 Vancouver

PeterRitchie — Thu, 26 Mar 2009 05:00:00 GMT

The schedule for DevTeach 2009 Vancouver has been announced (http://www.devteach.com/). There’s lots of great software development sessions from some of the leaders in our industry.

If you’re planning on improving yourself, this is the conference to go to. Not only can you attend excellent sessions; but you can hob-knob with the presenters and pick their brains.

If you have a friend or co-worker who’s interested, there’s a limited-time two-for-one offer for an even better price: http://www.devteach.com/Register.aspx

Who's Referencing Whom?

PeterRitchie — Fri, 12 Oct 2007 05:00:00 GMT

When developing any sort of application, debugging in inevitable. Sometimes, part of that debugging means trying to figure out why objects haven't been collected and therefore figuring out what object is referencing the object that has yet to be collected.

There's many reasons why you'd want to find out what object is referencing, like suspected memory "leaks".

With Visual Studio (and MDbg) you can use a tool called SOS (or Son Of Strike). This is included in the .NET installation. To use SOS you first need to enable unmanaged debugging in your project (Project\Properties, Debug tab, check "Enable unmanaged code debugging" in the "Enable Debuggers" section). Once unmanaged debugging is enabled you can then debug your application. To use SOS once debugging, you need to load the extension (every time a new debugging session is started). Once a breakpoint has been hit, open the Immediate Window and type .load sos which should result in the following:

.load sos
extension C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\sos.dll loaded

With SOS loaded, you can find out if any objects of a particular type are currently in memory with the "dumpheap -type" command, for example:

!dumpheap -type NamespaceName.TypeName
Address       MT     Size
012b2db8 009159c4      328
total 1 objects
Statistics:
      MT    Count    TotalSize Class Name
009159c4        1          328 NamespaceName.TypeName
Total 1 objects

This lists all objects of the requested type, their address, their MethodTable (MT), and the count of each object per MethodTable.

Once you have the object's address you can then find out what objects are referencing that particular instance. This is done with the gcroot command:

!gcroot 012b2db8
Note: Roots found on stacks may be false positives. Run "!help gcroot" for
more info.
Error during command: warning! Extension is using a feature which Visual Studio does not implement.

Scan Thread 4756 OSTHread 1294
ESP:12f0dc:Root:012b2db8(WindowsApplication1.Form1)->
012bb104(WindowsApplication1.Form2)->
012bb254(System.Collections.Generic.List`1[[NamespaceName.TypeName, WindowsApplication1]])->
012bc178(System.Object[])->
012bc16c(NamespaceName.TypeName)
Scan Thread 3496 OSTHread da8

In this particular example, the above tells us that our object (012bc16c(NamespaceName.TypeName)) is referenced by an Object array (012bc178(System.Object[])), which is referenced by a List<T> object (012bb254(System.Collections.Generic.List`1[[NamespaceName.TypeName, WindowsApplication1]])), which is referenced by Form2 (012bb104(WindowsApplication1.Form2)), which is referenced by a Form1 object(ESP:12f0dc:Root:012b2db8(WindowsApplication1.Form1)).

.NET Framework 2.0 Service Pack 1

PeterRitchie — Tue, 22 May 2007 05:00:00 GMT

I noticed mention of .NET Framework 2.0 Service Pack 1 on a Microsoft site today.

The BCL Team's latest blog entry http://blogs.msdn.com/bclteam/archive/2007/05/21/the-regexoptions-compiled-flag-and-slow-performance-on-64-bit-net-framework-2-0-josh-free.aspx mentions a fix that will make it into the .NET Framework 2.0 SP 1. Seems an inevitable release of SP1 for .NET Framework 2.0 is pretty official.

Search results for 'app:weblogs' matching tags 'Visual Studio 2005' and '.NET 2.0'

DevTeach 2009 Vancouver

Who's Referencing Whom?

.NET Framework 2.0 Service Pack 1