El mar, 02-09-2008 a las 17:58 +0200, phcoder escribió: > > but it seems terser > > than mine even though it's a bit more difficult to understand because > > you use double pointers to avoid my handling of the head case. I don't > > understand the purpose of doubly-linking the list though... > > > The goal is to avoid walking through list when deleting an entry from it. But you negate any performance gain when you _do_ traverse the list to add an entry to it instead of just make it the new head as I do. Besides, even for that, double indirection should be avoided in the structure previous pointer because it makes things oh-so-incredibly confusing.
Besides, I think the "user" (i.e. module) visible type returned by _add and taken by _remove should be a "blank hidden type", i.e. you don't need to declare "struct grub_preboot_t" in loader.h because the public interface only uses _pointers_ to it, whose size is known. This is all the C compiler requires and you avoid polluting the namespace with internal implementation details. I recommend the following typedefs: typedef struct grub_preboot_t* grub_preboot_hnd; typedef grub_err_t *(grub_preboot_func)(int noreturn); So that the prototypes would look grub_preboot_hnd add(grub_preboot_func f); void remove(grub_preboot_hnd handle); > >> Whether we need also interface for adding "postboot" commands? (in case > >> boot_function returns) > > I don't think it would offer a lot of functionality because most loaders > > don't return on failure, they just get stuck or their payload > > triple-faults and reboots. > > It's the case for i386-pc loaders but not the case of some other targets > (e.g. EFI). So the question remains. And same question for abortion procedures. This is a spinous matter because clean handling is difficult, not always possible and requires registering "undo" functions, i.e. more bloat in kernel. -Habbit
signature.asc
Description: Esta parte del mensaje está firmada digitalmente
_______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
