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* [PATCH][2.5] Single linked lists for Linux,v2
@ 2002-09-25 22:50 Lightweight Patch Manager
  2002-09-25 23:02 ` Thunder from the hill
  2002-09-26  0:08 ` Rik van Riel
  0 siblings, 2 replies; 8+ messages in thread
From: Lightweight Patch Manager @ 2002-09-25 22:50 UTC (permalink / raw)
  To: Linux Kernel Mailing List; +Cc: Tomas Szepe, Ingo Molnar

Again single linked lists...

--- /dev/null	Wed Dec 31 17:00:00 1969
+++ slist-2.5/include/linux/slist.h	Wed Sep 25 16:47:26 2002
@@ -0,0 +1,109 @@
+#ifdef __KERNEL__
+#ifndef _LINUX_SLIST_H
+#define _LINUX_SLIST_H
+
+#include <asm/processor.h>
+
+/*
+ * Type-safe single linked list helper-functions.
+ * (originally taken from list.h)
+ *
+ * Thomas 'Dent' Mirlacher, Daniel Phillips,
+ * Andreas Borgk, Thunder from the hill
+ */
+
+#define INIT_SLIST_HEAD(name)			\
+	(name->next = name)
+
+#define SLIST_HEAD(type,name)			\
+	typeof(type) name = INIT_SLIST_HEAD(name)
+
+/**
+ * slist_add_front - add a new entry at the first slot, moving the old head
+ *		     to the second slot
+ * @new:	new entry to be added
+ * @head:	head of the single linked list
+ *
+ * Insert a new entry before the specified head.
+ * This is good for implementing stacks.
+ */
+
+#define slist_add_front(_new, _head)		\
+do {						\
+	(_new)->next = (_head);			\
+	(_head) = (_new);			\
+} while (0)
+
+
+
+/**
+ * slist_add - add a new entry
+ * @new:       new entry to be added
+ * @head:      head of the single linked list
+ *
+ * Insert a new entry before the specified head.
+ * This is good for implementing stacks.
+ *
+ * Careful: if you do this concurrently, _head
+ * might get into nirvana...
+ */
+#define slist_add(_new, _head)			\
+do {						\
+	(_new)->next = (_head)->next;		\
+	(_head)->next = (_new);			\
+	(_new) = (_head);			\
+} while (0)
+
+/**
+ * slist_del -	remove an entry from list
+ * @head:	head to remove it from
+ * @entry:	entry to be removed
+ */
+#define slist_del(_head, _entry)		\
+do {						\
+	(_head)->next = (_entry)->next;		\
+	(_entry)->next = NULL;			\
+} while (0)
+
+/**
+ * slist_del_single -	untag a list from an entry
+ * @list:	list entry to be untagged
+ */
+#define slist_del_single(_list)			\
+	((_list)->next = NULL)
+
+/**
+ * slist_pop	-	pop out list entry
+ * @list:	entry to be popped out
+ *
+ * Pop out an entry from a list.
+ */
+#define slist_pop(_list) ({			\
+	typeof(_list) _NODE_ = _list;		\
+	if (_list) {				\
+	    (_list) = (_list)->next;		\
+	    _NODE_->next = NULL;		\
+	}					\
+	_NODE_; })
+
+/**
+ * slist_for_each	-	iterate over a list
+ * @pos:	the pointer to use as a loop counter.
+ * @head:	the head for your list (this is also the first entry).
+ */
+#define slist_for_each(pos, head)				\
+	for (pos = head; pos && ({ prefetch(pos->next); 1; });	\
+	    pos = pos->next)
+
+/**
+ * slist_for_each_del	-	iterate over a list, popping off entries
+ * @pos:       the pointer to use as a loop counter.
+ * @head:      the head for your list (this is also the first entry).
+ */
+#define slist_for_each_del(pos, head)			\
+	for (pos = slist_pop(head); pos &&		\
+    	    ({ prefetch(pos->next); 1; });		\
+	    pos = slist_pop(head))
+
+#endif /* _LINUX_SLIST_H */
+#endif /* __KERNEL__ */

-- 
Lightweight Patch Manager, without pine.
If you have any objections (apart from who I am), tell me


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-25 22:50 [PATCH][2.5] Single linked lists for Linux,v2 Lightweight Patch Manager
@ 2002-09-25 23:02 ` Thunder from the hill
  2002-09-26  0:08 ` Rik van Riel
  1 sibling, 0 replies; 8+ messages in thread
From: Thunder from the hill @ 2002-09-25 23:02 UTC (permalink / raw)
  To: Lightweight Patch Manager
  Cc: Linux Kernel Mailing List, Tomas Szepe, Ingo Molnar

Hi,

On Wed, 25 Sep 2002, Lightweight Patch Manager wrote:
> + * Andreas Borgk, Thunder from the hill

That poor guy's name is Andreas Bogk, for chrissake...

			Thunder
-- 
assert(typeof((fool)->next) == typeof(fool));	/* wrong */


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-25 22:50 [PATCH][2.5] Single linked lists for Linux,v2 Lightweight Patch Manager
  2002-09-25 23:02 ` Thunder from the hill
@ 2002-09-26  0:08 ` Rik van Riel
  2002-09-26  6:36   ` Thunder from the hill
  1 sibling, 1 reply; 8+ messages in thread
From: Rik van Riel @ 2002-09-26  0:08 UTC (permalink / raw)
  To: Lightweight Patch Manager
  Cc: Linux Kernel Mailing List, Tomas Szepe, Ingo Molnar

On Wed, 25 Sep 2002, Lightweight Patch Manager wrote:

> Again single linked lists...

And again with errors ;)


> +#define INIT_SLIST_HEAD(name)			\
> +	(name->next = name)
> +
> +#define SLIST_HEAD(type,name)			\
> +	typeof(type) name = INIT_SLIST_HEAD(name)

Fun, so the list head points to itself ...

> +#define slist_for_each(pos, head)				\
> +	for (pos = head; pos && ({ prefetch(pos->next); 1; });	\
> +	    pos = pos->next)

... imagine what that would do in combination with this macro.

Rik
-- 
Bravely reimplemented by the knights who say "NIH".

http://www.surriel.com/		http://distro.conectiva.com/

Spamtraps of the month:  september@surriel.com trac@trac.org


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-26  0:08 ` Rik van Riel
@ 2002-09-26  6:36   ` Thunder from the hill
  2002-09-26 14:58     ` Rik van Riel
  0 siblings, 1 reply; 8+ messages in thread
From: Thunder from the hill @ 2002-09-26  6:36 UTC (permalink / raw)
  To: Rik van Riel
  Cc: Lightweight Patch Manager, Linux Kernel Mailing List,
	Tomas Szepe, Ingo Molnar

Hi,

On Wed, 25 Sep 2002, Rik van Riel wrote:
> > +#define INIT_SLIST_HEAD(name)			\
> > +	(name->next = name)
> > +
> > +#define SLIST_HEAD(type,name)			\
> > +	typeof(type) name = INIT_SLIST_HEAD(name)
> 
> Fun, so the list head points to itself ...
> 
> > +#define slist_for_each(pos, head)				\
> > +	for (pos = head; pos && ({ prefetch(pos->next); 1; });	\
> > +	    pos = pos->next)
> 
> ... imagine what that would do in combination with this macro.

I'm aware of that possibility. What would you initialize it to, if not the 
list itself? (And BTW, anyone have a solution for slist_add()?)

We could set it to NULL, but where would we end?

#define INIT_SLIST_HEAD(name)				\
	(name->next = NULL)

#define SLIST_HEAD_INIT(name)	name

			Thunder
-- 
assert(typeof((fool)->next) == typeof(fool));	/* wrong */


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-26  6:36   ` Thunder from the hill
@ 2002-09-26 14:58     ` Rik van Riel
  2002-09-26 15:39       ` Thunder from the hill
  0 siblings, 1 reply; 8+ messages in thread
From: Rik van Riel @ 2002-09-26 14:58 UTC (permalink / raw)
  To: Thunder from the hill
  Cc: Lightweight Patch Manager, Linux Kernel Mailing List,
	Tomas Szepe, Ingo Molnar

On Thu, 26 Sep 2002, Thunder from the hill wrote:

> I'm aware of that possibility. What would you initialize it to, if not
> the list itself? (And BTW, anyone have a solution for slist_add()?)

If I were you, I'd take a large piece of paper and make
a drawing of what the data structure looks like and what
the various macros/functions are supposed to do.

That should make things easier.

regards,

Rik
-- 
A: No.
Q: Should I include quotations after my reply?

http://www.surriel.com/		http://distro.conectiva.com/


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-26 14:58     ` Rik van Riel
@ 2002-09-26 15:39       ` Thunder from the hill
  2002-09-26 16:17         ` Nicolas Pitre
  2002-09-26 16:37         ` Rik van Riel
  0 siblings, 2 replies; 8+ messages in thread
From: Thunder from the hill @ 2002-09-26 15:39 UTC (permalink / raw)
  To: Rik van Riel; +Cc: Linux Kernel Mailing List, Tomas Szepe, Ingo Molnar

Hi,

On Thu, 26 Sep 2002, Rik van Riel wrote:
> If I were you, I'd take a large piece of paper and make
> a drawing of what the data structure looks like and what
> the various macros/functions are supposed to do.

Well, I know what they _should_ do. But I don't know what I should 
initialize an empty list entry to. That's not got much spam in it...

			Thunder
-- 
assert(typeof((fool)->next) == typeof(fool));	/* wrong */


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-26 15:39       ` Thunder from the hill
@ 2002-09-26 16:17         ` Nicolas Pitre
  2002-09-26 16:37         ` Rik van Riel
  1 sibling, 0 replies; 8+ messages in thread
From: Nicolas Pitre @ 2002-09-26 16:17 UTC (permalink / raw)
  To: Thunder from the hill
  Cc: Rik van Riel, Linux Kernel Mailing List, Tomas Szepe, Ingo Molnar

On Thu, 26 Sep 2002, Thunder from the hill wrote:

> Hi,
> 
> On Thu, 26 Sep 2002, Rik van Riel wrote:
> > If I were you, I'd take a large piece of paper and make
> > a drawing of what the data structure looks like and what
> > the various macros/functions are supposed to do.
> 
> Well, I know what they _should_ do. But I don't know what I should 
> initialize an empty list entry to. That's not got much spam in it...

Try with NULL.


Nicolas


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH][2.5] Single linked lists for Linux,v2
  2002-09-26 15:39       ` Thunder from the hill
  2002-09-26 16:17         ` Nicolas Pitre
@ 2002-09-26 16:37         ` Rik van Riel
  1 sibling, 0 replies; 8+ messages in thread
From: Rik van Riel @ 2002-09-26 16:37 UTC (permalink / raw)
  To: Thunder from the hill; +Cc: Linux Kernel Mailing List, Tomas Szepe, Ingo Molnar

On Thu, 26 Sep 2002, Thunder from the hill wrote:
> On Thu, 26 Sep 2002, Rik van Riel wrote:
> > If I were you, I'd take a large piece of paper and make
> > a drawing of what the data structure looks like and what
> > the various macros/functions are supposed to do.
>
> Well, I know what they _should_ do. But I don't know what I should
> initialize an empty list entry to.

And now you contradict yourself ;)

Please make a detailed picture of the data structure on
a piece of paper so you can check the code against the
picture and see if it really is doing the right thing.

Rik
-- 
A: No.
Q: Should I include quotations after my reply?

http://www.surriel.com/		http://distro.conectiva.com/


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2002-09-26 16:32 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2002-09-25 22:50 [PATCH][2.5] Single linked lists for Linux,v2 Lightweight Patch Manager
2002-09-25 23:02 ` Thunder from the hill
2002-09-26  0:08 ` Rik van Riel
2002-09-26  6:36   ` Thunder from the hill
2002-09-26 14:58     ` Rik van Riel
2002-09-26 15:39       ` Thunder from the hill
2002-09-26 16:17         ` Nicolas Pitre
2002-09-26 16:37         ` Rik van Riel

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