From: Alex Riesen <raa.lkml@gmail.com>
Date: Tue, 24 Apr 2007 09:30:07 GMT
Subject: Re: [PATCH] Fix handle leak in write_tree
Message-ID: <81b0412b0704240230x3a5b473k5da3d45d9c997c3b@mail.gmail.com>
In-Reply-To: <7vps5u9wsk.fsf@assigned-by-dhcp.cox.net>

On 4/24/07, Junio C Hamano <junkio@cox.net> wrote:
> > How about something like this (just interface):
> >
> > struct lock_file
> > {
> >       struct lock_file *next;
> >       pid_t owner;
> >       int fd;
> >       char on_list;
> >       char filename[PATH_MAX];
> > };
> >
> > struct lock_file *open_locked(const char *path, int die_on_error);
> > struct lock_file *open_index_locked(int die_on_error);
> > void commit_lock_file(struct lock_file *); /* always assuming .lock */
> > void rollback_lock_file(struct lock_file *);
>
> I agree that making commit and rollback close the file
> descriptor and lock holders to use lock->fd for write() makes
> more sense, although it is a bit unclear from the above set of
> function signatures what your plan on the lifetime rule for
> "struct lock_file" is.  If it will be linked to the list given
> to the atexit() handler and the caller of open_locked() never
> frees it, I think I am fine with the interface.

I actually expected the caller to define the lifetime. atexit is not exactly
libification-effort friendly. I could imagine open*locked with an additional
argument for atexit registration, I just don't like the idea (dislike
die_on_error
too). Isn't such kind of resource control _generally_ nicer to implement
in the top levels of a program?