[pacman-dev] FS#9424 : storing pid in db.lck

[Xavier]

On Tue, Feb 19, 2008 at 05:26:00PM +0100, Nagy Gabor wrote:
> Hi!
> 1. I don't really understand why this /tmp/* stuff is needed (and tmpfile
> shouldn't be PACMAN specific). We could write the pid to the lockfile directly.

There is an explanation in the comments :
"Also, I was wondering why good locking systems create symlinks to temporary
files. I found why: the pid that pacman had when the db.lck file was created
can be assigned to another process after a reboot, so the workaround for this
is to create db.lck in /tmp and symlink it to /var/lib/pacman. This way
nonroot users still can't lock pacman db, but after a reboot the lock file is
gone."


> 2. Just for safety we could compare our current pid and the lock-pid on lockfile
> removal.
> 

Maybe (patches always welcome :)).