lepreau@utah-cs.UUCP (Jay Lepreau) (03/16/84)
That's the whole point, that EVERY program that writes on /usr/spool/mail/user must observe the same locking protocol. Another problem with the locking as distributed (in 4.x bsd at least) is that the timeout in binmail is too short: only 30 seconds. After that binmail declares the lock defunct and merrily appends to the mail file. That can easily be exceeded on a not very loaded system by a user with a big mailbox, and many keep their boxes full of pending mail. As distributed, UCB Mail has the long timeout of 5 minutes, but that is the program that normally only needs a short timeout, as /bin/mail will append quickly. Anyway, I have extracted the relevant locking code into a module mlock.c containing, ah hah, mlock and mfree, which lock on /tmp. If people want I'll send it out (it's pretty minor, but it's done). I didn't use 4.2 file locking locking so it is portable. Jay Lepreau
phil@amd70.UUCP (Phil Ngai) (03/22/84)
Some time ago there was discussion on the proper mode of /usr/spool/mail
and it was pointed out that /usr/ucb/Mail does its locking there so it
needs to be writable. Someone said they moved the locking to /tmp.
Isn't it also necessary to worry about the locking protocol used by
/bin/mail, which /etc/delivermail uses for local mail delivery?
--
Phil Ngai (408) 988-7777 {ucbvax,decwrl,ihnp4,allegra,intelca}!amd70!phil