[cs631apue] [CS 631] Semaphores

[tparisi]

Hi,
I am trying to use semaphores in the web server to prevent a file from 
being altered by another process when being read by the server.  The 
current logic of the locking procedure for every request is:

1. create the lock/test for existence
2. lock the file
3. serve the file
4. release the lock

That all works.  My main concern is that in class we were shown that 
the locks that we create (my understanding is that semaphore lock is 
attached to a single file) stay around long after a process terminates, 
I would like to destroy the lock when the daemon exits.  However, there 
is only one semaphore ID in the parent process so I'll only be able to 
destroy on such lock right?  Right now, I'm of the understanding that 
destroying the lock in the child is a poor choice because another forked 
child of the parent could be trying to acquire that lock and destroying 
it would mess the operations up.

I'm really stumped here so any helpful clues would be just great.

Also, on a side note, are we allowed to use outside code as long as its 
cited in someway?
Thanks,
Tom