We have been experimenting with a Delphi Indy (SVN trunk) client and Apache with mod_php. A PHP script is called which registers a shutdown function.
During testing this shutdown function is called only once the script has ended and connection_status() comes back zero.
If I use CURL and hit Ctrl-C during the script's execution, CURL sends a TCP packet with the RST flag set to boolean true. This does trigger the shutdown function and connection_status() comes back one. If the connection times out, a TCP FIN flag is switched on but the shutdown function does not trigger - in fact the Apache process goes into CLOSE_WAIT until the PHP script has finished executing. If I use Indy, the only flag that gets set is FIN.
With all this in mind can we get Indy to send a TCP packet with an RST flag set to true? We want to do this when the connection times out (solving the problem we are testing for).
Indy always tries to close a connection gracefully, which will not send a RST flag. If you need that, you will have to forcibly close the connection yourself.