mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-10-29 05:40:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Replace list.h with its own version

Browse source 
We copied include/list.h from Linux kernel, and it's of course in
GPLv2.  This has raised concerns to many people, as it's not clear
whether such a code is considered to be completely trivial, thus it
might be seen as a derivative work, which takes effect in GPL, as
suggested by Clemens.

For clearing the situation, this patch replaces the existing list.h
implementation from a new version.  The API is kept to be compatible,
but the codes were written from full scratch under LGPL, to be aligned
with other alsa-lib codes.

Reported-by: Clemens Lang <clemens.lang@bmw-carit.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2015-07-27 12:32:37 +02:00
parent 77b6be6387
commit d0e13f8774
1 changed files with 72 additions and 144 deletions
Download patch file Download diff file Expand all files Collapse all files

216
include/list.h
View file

@ -1,174 +1,102 @@
/* Doubly linked list macros compatible with Linux kernel's version
* Copyright (c) 2015 by Takashi Iwai <tiwai@suse.de>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*/
#ifndef _LIST_H
#define _LIST_H
/*
* This code was taken from the Linux 2.4.0 kernel. [jaroslav]
*/
#include <stddef.h>
/*
* Simple doubly linked list implementation.
*
* Some of the internal functions ("__xxx") are useful when
* manipulating whole lists rather than single entries, as
* sometimes we already know the next/prev entries and we can
* generate better code by using them directly rather than
* using the generic single-entry routines.
*/
#ifndef LIST_HEAD_IS_DEFINED
struct list_head {
struct list_head *next, *prev;
struct list_head *next;
struct list_head *prev;
};
#endif
#define LIST_HEAD_INIT(name) { &(name), &(name) }
/* one-shot definition of a list head */
#define LIST_HEAD(x) \
struct list_head x = { &x, &x }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
#define INIT_LIST_HEAD(ptr) do { \
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)
/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
static __inline__ void __list_add(struct list_head * _new,
struct list_head * prev,
struct list_head * next)
/* initialize a list head explicitly */
static inline void INIT_LIST_HEAD(struct list_head *p)
{
next->prev = _new;
_new->next = next;
_new->prev = prev;
prev->next = _new;
p->next = p->prev = p;
}
/**
* list_add - add a new entry
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
static __inline__ void list_add(struct list_head *_new, struct list_head *head)
{
__list_add(_new, head, head->next);
}
#define list_entry_offset(p, type, offset) \
((type *)((char *)(p) - (offset)))
/**
* list_add_tail - add a new entry
* @new: new entry to be added
* @head: list head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
/* list_entry - retrieve the original struct from list_head
* @p: list_head pointer
* @type: struct type
* @member: struct field member containing the list_head
*/
static __inline__ void list_add_tail(struct list_head *_new, struct list_head *head)
{
__list_add(_new, head->prev, head);
}
#define list_entry(p, type, member) \
list_entry_offset(p, type, offsetof(type, member))
/*
* Delete a list entry by making the prev/next entries
* point to each other.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
/* list_for_each - iterate over the linked list
* @p: iterator, a list_head pointer variable
* @list: list_head pointer containing the list
*/
static __inline__ void __list_del(struct list_head * prev,
struct list_head * next)
{
next->prev = prev;
prev->next = next;
}
#define list_for_each(p, list) \
for (p = (list)->next; p != (list); p = p->next)
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
* Note: list_empty on entry does not return true after this, the entry is in an undefined state.
/* list_for_each_safe - iterate over the linked list, safe to delete
* @p: iterator, a list_head pointer variable
* @s: a temporary variable to keep the next, a list_head pointer, too
* @list: list_head pointer containing the list
*/
static __inline__ void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
}
#define list_for_each_safe(p, s, list) \
for (p = (list)->next; s = p->next, p != (list); p = s)
/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.n
/* list_add - prepend a list entry at the head
* @p: the new list entry to add
* @list: the list head
*/
static __inline__ void list_del_init(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
/**
* list_empty - tests whether a list is empty
* @head: the list to test.
*/
static __inline__ int list_empty(struct list_head *head)
{
return head->next == head;
}
/**
* list_splice - join two lists
* @list: the new list to add.
* @head: the place to add it in the first list.
*/
static __inline__ void list_splice(struct list_head *list, struct list_head *head)
static inline void list_add(struct list_head *p, struct list_head *list)
{
struct list_head *first = list->next;
if (first != list) {
struct list_head *last = list->prev;
struct list_head *at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
p->next = first;
first->prev = p;
list->next = p;
p->prev = list;
}
/**
* list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
/* list_add_tail - append a list entry at the tail
* @p: the new list entry to add
* @list: the list head
*/
#define list_for_each(pos, head) \
for (pos = (head)->next ; pos != (head); pos = pos->next)
static inline void list_add_tail(struct list_head *p, struct list_head *list)
{
struct list_head *last = list->prev;
/**
* list_for_each_safe - iterate over a list safely (actual pointer can be invalidated)
* @pos: the &struct list_head to use as a loop counter.
* @next: the &struct list_head to use to save next.
* @head: the head for your list.
*/
#define list_for_each_safe(pos, npos, head) \
for (pos = (head)->next, npos = pos->next ; pos != (head); pos = npos, npos = pos->next)
last->next = p;
p->prev = last;
p->next = list;
list->prev = p;
}
/**
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_struct within the struct.
*/
#define list_entry(ptr, type, member) \
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
/* list_del - delete the given list entry */
static inline void list_del(struct list_head *p)
{
p->prev->next = p->next;
p->next->prev = p->prev;
}
/**
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @offset: offset of entry inside a struct
*/
#define list_entry_offset(ptr, type, offset) \
((type *)((char *)(ptr)-(offset)))
/* list_empty - returns 1 if the given list is empty */
static inline int list_empty(const struct list_head *p)
{
return p->next == p;
}
#endif /* _LIST_H */