news:1131564602.694642.104070@g14g2000cwa.googlegroups.com...
>I have a .net app that uses a lot of calls to System.Net.WebRequest,
> and it appears to be leaking memory.  I've spent a couple of days
> working with the excellent .net memory profiler from Scitech
> (http://www.scitech.se/) trying to find the leak, and all I've managed
> to find is that the win32 (unmanaged) heap seems to keep growing.  I
> wrote this (pretty non-realistic) code in a test app to try duplicating
> the problem:
>
> while(true)
> {
>     try
>     {
>          System.Net.WebRequest
> req=System.Net.WebRequest.Create(@"http://chris/TestWebService/TestService.asmx?WSDL");
>          System.Net.WebResponse resp=req.GetResponse();
>          resp.Close();
>     }
>     catch(Exception ex)
>     {
>          MessageBox.Show(ex.ToString());
>    }
> }
>
>
> Note that this was just inside a button click event of a winform
> application.  The exception condition never got hit, and the app just
> kept hammering away at my local web server.  Checking the profiler, I
> saw the number of undisposed instances of System.Net.HttpWebResponse,
> System.Net.ConnectStream, and System.Threading.ManualResetEvent
> increasing with each iteration.  Shouldn't the resp.Close() statement
> release the resources?  There's nothing in the documentation about
> doing any sort of disposal on the request object, so it appears that
> only the response needs to be disposed, and so far, that doesn't seem
> to be happening. I've also tried the above code casting the response to
> an HTTPWebResponse, but that has no effect.  I also tried removing the
> resp.Close() statement, which had no effect (the undisposed objects
> still showed up in the profiler).  Is there something else I need to do
> to fix this memory leak?
>
> Thanks for your help,
>
> Chris
>

news:1131569401.178280.239950@g44g2000cwa.googlegroups.com...
> Thanks for the reply Michael.  I tried your suggestion just after I
> posted actually, and I found that putting the using statement in got
> rid of the undisposed webResponse objects, but left the
> System.Net.ConnectStream and System.Threading.ManualResetEvent objects
> undisposed.  I know that the ManualResetEvent is created by
> HTTPWebRequest.GetResponse, and the ConnectStream is called by
> HttpWebRequest.BeginSubmitRequest.
>
> The first problem is that these last two undisposed instances are
> created by the request, which does not implement IDisposable, and does
> not have anything in the documentation regarding unmanaged resources.
> Is there something that I need to do to clean up after a WebRequest?
>
> Second, why does the using statement work for the response, but not the
> close() method?  The documentation explicitly states  :
>
> "The Close method closes the response stream and releases the
> connection to the Internet resource for reuse by other requests.  Note
> You must call either the Stream.Close or the HttpWebResponse.Close
> method to close the stream and release the connection for reuse. It is
> not necessary to call both Stream.Close and HttpWebResponse.Close, but
> doing so does not cause an error. Failure to close the stream will
> cause your application to run out of connections."
>
> Does this mean that Close() doesn't actually call Dispose()?  I'm a
> little confused-I thought that this was the reason that the close
> method existed on stream objects.  The code that I'm using is almost
> identical to the MSDN sample code.
>