Re: pidfile_lock(3)

[Roy Marples <roy%marples.name@localhost>]

On Sunday 20 March 2016 23:05:12 Christos Zoulas wrote:
> In article <1547312.W6Y7Ml981D%uberpc.marples.name@localhost>,
> Roy Marples  <roy%marples.name@localhost> wrote:
> 
> There is no need for pidfile_lock(), just fix pid_file() to return pid_t.
> I've audited the code in the tree and the code that checks, checks for -1.
> The compat code below is probably wrong anyway.

Ah, but it needs to check for != 0 as it can return the pid who has the lock, 
which is itself an error.

> 
> christos
> 
> >+/* The old function.
> >+ * Historical behaviour is that pidfile is not re-written
> >+ * if path has not changed.
> >+ *
> >+ * Returns 0 on success, otherwise -1.
> >+ * As such we have no way of knowing the pid who owns the lock. */
> >
> > int
> > pidfile(const char *path)
> > {
> >
> >+	pid_t pid;
> >
> >-	if (path == NULL || strchr(path, '/') == NULL) {
> >-		char *default_path;
> >-
> >-		if ((default_path = generate_varrun_path(path)) == NULL)
> >-			return -1;
> >-
> >-		if (create_pidfile(default_path) == -1) {
> >-			free(default_path);
> >-			return -1;
> >-		}
> >-
> >-		free(default_path);
> >-		return 0;
> >-	} else
> >-		return create_pidfile(path);
> >+	pid = pidfile_lock(path);
> >+	return pid == 0 ? 0 : -1;
> >
> > }
> >
> >-=-=-=-=-=-