Avoiding memory leaks in SharePoint custom development

When you doing custom development in SharePoint like webparts, event receiver, etc.. it is important to consider memory leaks. Creating the component in safe way lead to improve the performance.  There are some points we can consider to avoid memory leaks.

1.       Use Dispose() method. 

2.       Use SPDisposeCheck utility to identify issues.

Dispose() is not related to SharePoint, it is provided in .NET. As a .NET developer we have to know how to correctly release the resources while working with the objects. .NET framework has a concept of garbage collection, provided by Common Language Runtime. Whenever you create an instance of managed type, when it is no longer used, the Garbage Collector will automatically release the allocated memory. But this is non deterministics (unpredictable).

.NET framework provide IDisposable interface which expose a Dispose() method that you can call explicitly to release the unmanaged resources.

To use Dispose technique you can follow one of the following methods. 

1. Use the using keyword

    Ex:

   using (SPSite site = new SPSite(“http://address”))

        {

           //your code

        }

 2. Use try/finally code block

    Ex:

  SPSite site = null;

  try               

     {

         site = new SPSite(“http://address”);

         //your code

     }

  finally

     {

       if (site != null)

          site.Dispose();

      }

 3. Explicitly call Dispose() method.

      Ex:

    SPSite site = new SPSite(“http://address”);

       //your code

    site.Dispose();

SPDisposeCheck is a tool that helps the developers and administrators to check custom SharePoint solutions that use the SharePoint Object Model. It measures against dispose best practices. Following is the way how to use SPDisposeCheck utility. 

SPDisposeCheck is a command line tool normally installed to this location “C:\Program Files (x86)\Microsoft\SharePoint Dispose Check”.

Go to any dll that you have developed using Visual Studio. My dll path is: “C:\Users\t-ictdev05\Documents\Visual Studio 2010\Projects\TestSPProjects\BlogPost\BlogPost\bin\Debug”.

Now open the command prompt and enter the following command:

“C:\Program Files (x86)\Microsoft\SharePoint Dispose Check\ SPDisposeCheck.exe” “C:\Users\t-ictdev05\Documents\Visual Studio 2010\Projects\TestSPProjects\BlogPost\BlogPost\bin\Debug”

It will show the problems in the specified dll.

If you want you can write this result to a txt file by using following command.

“C:\Program Files (x86)\Microsoft\SharePoint Dispose Check\ SPDisposeCheck.exe” “C:\Users\t-ictdev05\Documents\Visual Studio 2010\Projects\TestSPProjects\BlogPost\BlogPost\bin\Debug” >result.txt

By using this utility you can identify what are the object we can dispose to develop a safe code.