How to detect a handle leak with a GC

[joproulx]

After trying to investigate a handle leak problem in my application, I
found out this post which pretty much describes the behavior that I
have experienced:
http://www.dotnet247.com/247reference/msgs/51/255221.aspx

And here is part of my code:

private void Socket_AcceptConnectCallback(IAsyncResult ar)
{
Socket socket = (Socket)ar.AsyncState;

if( socket==null )
return;

if ( socket.Connected)
{
socket.EndConnect(ar);
// Connection succeeded
CreateNewConnection(socket, out
m_iClientMainConnection);
}
else
{
socket.Close(); // Doesn't release all the handles!!!
socket = null;
}
}

The problem is that even though I close my socket when it fails to
connect, the handle count keeps going up. From the post mentionned
above, this doesn't seem to be a leak but the way the GC manage the
lifetime of the handles. After a certain time where the handle count
can reach a really high number, the GC will release a bunch of them.

My questions are: How can you determine that you really are confronted
to a handle leak when you never know when the GC will release the
handle? Is there a way to tell the GC to always release the handle when
requested by the code for testing purpose? If I do not call Close() on
the socket, will it really leak or is the GC will eventually release
the handle?

Best regards,
Jonathan

 

[joproulx]

Well, after isolating the problem further more it seems that the leak
doesn't occur at this point. I guess that the behaviour described in
the link I was referencing to in my precedent post is not vaild
anymore.

But still I was wondering if the GC can hold a reference to a handle
even though an object that was holding this reference was diposed
correctly?

 

[ghytred]

I notice you only call socket.EmdConnect(ar) if the connect succeeds.
Didn't you say that it usually fails?

What happens if you try to call EndConnect whether or not it succeeds?

Cheers -

Simon

private void Socket_AcceptConnectCallback(IAsyncResult ar)
{
Socket socket = (Socket)ar.AsyncState;

if( socket==null )
return;

if ( socket.Connected)
{
socket.EndConnect(ar);
// Connection succeeded
CreateNewConnection(socket, out
m_iClientMainConnection);
}
else
{

// always call end for async functions
socket.EndConnect(ar);

 

[joproulx]

Yes I have tried it but I have an SocketException with the messge: "No
connection could be made because the target machine actively refused
it". So I figured that it should only be called when the connection
succeed.

Jonathan