Closing an open file from a resource manager

Is there a correct way to close an open file from wihin a resource manager?

To explain, one of my resource managers provides some resources which we
download to remote PCs using a browser. If Internet Explorer is used, and
the transfer is cancelled from the download dialog, the connection to the
resource manager remains open. Using “sin fds” I can see that httpd
(Apache) retains a connection. Closing the browser window ends the
connection. If I use Opera instead of IE, this behaviour is not present.

I would like the resource manager to discard idle connections after some
period. Is there a way to tell QNX to close the file and trigger the
normal close sequence (calling io_close etc) from within the resource
manager?

Regards

William Morris