pipe of death

::1 - - [04/Jul/2006:11:00:47 +0900] "GET / HTTP/1.0" 404 198 "-" "Apache/2.2.2 (Unix) (internal dummy connection)"

| This function connects to the server, then immediately closes the
| connection.
| This permits the MPM to skip the poll when there is only one listening
| socket, because it provides a alternate way to unblock an accept()
| when the pod is used.

| The pipe of death is used to tell all child processes that it is time
| to die gracefully.