Why does httpd seem to still be bound to an address when the service is supposedly stopped?

Question

This may be similar, but the reverse, of another question I asked. In that question, the issue was the service was running but not yet listening on the port. That I can understand, but this situation makes less sense to me: my service has already stopped, but is still listening.

Almost every time I go to restart my development Apache 2.2 service on my CentOS 6.4 box--if it's been some undefined amount of time or hits or something since the last restart--I have to do it twice, because it's still listening. Thereafter it seems to work fine.

$ sudo service httpd-dev restart
[sudo] password for kev: 
Stopping httpd:                                            [  OK  ]
Starting httpd: (98)Address already in use: make_sock: could not bind to address 192.168.99.44:80
no listening sockets available, shutting down
Unable to open logs
                                                           [FAILED]
$ sudo service httpd-dev restart
Stopping httpd: cat: /var/run/httpd/httpd-dev-80.pid: No such file or directory
kill: usage: kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]
                                                           [FAILED]
Starting httpd:                                            [  OK  ]
$ sudo service httpd-dev restart
Stopping httpd:                                            [  OK  ]
Starting httpd:                                            [  OK  ]

How can this be? Doesn't it stop listening the moment the service script shuts it down?

Answer 1

If I put a sleep 1 line between stop and start in the init.d script, the problem goes away. Perhaps the main httpd process has shut down but the child processes are still somehow listening for an extra moment.