haiku/headers/private/kernel/kqueue.h
Axel Dörfler ab25550f8e Added a initque() inline function.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1972 a95241bf-73f2-0310-859d-f6bbb57e9c96
2002-11-17 01:35:01 +00:00

60 lines
1.2 KiB
C

/*
** Copyright 2002, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
** Distributed under the terms of the OpenBeOS License.
*/
#ifndef KQUEUE_H
#define KQUEUE_H
/* The name "que" actually means that it is a very
* light-weight implementation of a queue ;-))
*/
/* The object that is put into a queue must begin with these
* fields, but it doesn't have to be this structure.
*/
struct quehead {
struct quehead *next;
struct quehead *prev;
};
/** Initializes a queue to be used */
static inline void
initque(void *_head)
{
struct quehead *head = (struct quehead *)_head;
head->next = head->prev = head;
}
/** Inserts an element (_element) to the queue (_head) */
static inline void
insque(void *_element, void *_head)
{
struct quehead *element = (struct quehead *)_element,
*head = (struct quehead *)_head;
element->next = head->next;
element->prev = head;
head->next = element;
element->next->prev = element;
}
/** removes an element from the queue it's currently in */
static inline void
remque(void *_element)
{
struct quehead *element = (struct quehead *)_element;
element->next->prev = element->prev;
element->prev->next = element->next;
element->prev = 0;
}
#endif /* KQUEUE_H */