On Jul 21, 2006, at 5:15 AM, Jachym Holecek wrote:

> Hello,
>
> I made some changes to the device tree traversal API [*]:
>
>   * Change names as per chap's comment (s/DIF_TOPDOWN/DIF_PREORDER,
>     s/DIF_DOWNTOP/DIF_POSTORDER).
>   * Remove traversal stack depth limit from device_iterator_alloc().
>   * Make it possible to reuse one iterator object for either traversal
>     direction.
>   * Fix allocation bug (thanks Magnus Larsson).
>
> New usage example:
>
> 	deviter_t 		di;
> 	device_t 		dv;
>
> 	di = device_iterator_alloc();
> 	if (di == NULL)
> 		panic("borked");
>
> 	device_iterator_init(di, TAILQ_FIRST(&alldevs),
> 	    DIF_PREORDER | DIF_WAITOK);
>
> 	while ((dv = device_iterator_foreach(di)) != NULL)
> 		printf("FOO %s\n", device_xname(dv));
>
> 	device_iterator_init(di, TAILQ_FIRST(&alldevs),
> 	    DIF_POSTORDER | DIF_WAITOK);
>
> 	while ((dv = device_iterator_foreach(di)) != NULL)
> 		printf("BAR %s\n", device_xname(dv));
>
> 	device_iterator_free(di);

Why do you need to pass TAILQ_FIRST(&alldevs)?  Why wouldn't that be
used every time?  I think removing that argument would be cleaner.