64 lines
1.4 KiB
C
64 lines
1.4 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;
|
|
};
|
|
|
|
/* You can use this macro to iterate through the queue. */
|
|
#define kqueue_foreach(head, element) \
|
|
for ((element) = (void *)(head)->next; (element) != (void *)(head); (element) = (void *)((struct quehead *)(element))->next)
|
|
|
|
|
|
/** 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 */
|