On Sun, 2007-06-10 at 10:20 -0700, Linus Torvalds wrote: > > On Sun, 10 Jun 2007, Rusty Russell wrote: > > > > The current list.h has the same type for list elements and list heads > > even though most code and coders treat them as distinct. > > I think the old list.h is technically superior to yours. > > Exactly *because* nodes and heads are interchangeable. > > In fact, you are incorrect that "most code" treat them as distinct. Most > code that uses list.h in fact uses it as a list of entries, often without > any head at all (and each *entry* is a point of removal), because the way > to actually *find* the structure that contains the lists is separate from > the lists themselves.
Sorry, do you really believe a ring is "often" the case? It's not entirely trivial to audit, but I can do a random sample of 100 list_heads. The list iterators reinforce the "standalone head" model (ie. it's not called list_for_each_other_entry), and they're pretty popular. > The Linux kernel list.h is _better_ than most stupid list implementations > that think that a head node is different from the list node. Exactly > because it very naturally supports the notion of "this structure exists in > a 'ring of entries'" where each node is 100% equivalent to any other node, > and there _is_ no head. I agree it's a wonderful feature, but you talk about "no head" but they're all called "list_head"? In my version, they'd all be list_node, and you can trivially treat it as a head with ->h. It's a little more work for rings, but it's more explicit and gives us type checking on the common case. Thanks for your consideration, Rusty. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
