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