10.2.3 queue.h: Generic queues

 

SYNOPSIS

#include <oskit/queue.h>

struct queue_entry  {

		struct queue_entry	*next;		/* next element */
		struct queue_entry	*prev;		/* previous element */
	 

};

typedef struct queue_entry *queue_t ;
typedef struct queue_entry queue_head_t ;
typedef struct queue_entry queue_chain_t ;
typedef struct queue_entry *queue_entry_t ;

DESCRIPTION

Macros and structures for implementation of a ``queue'' data type. The implementation uses a doubly-linked list and supports operations to insert and delete anywhere in the list.

queue_init(q)

  Initialize the given queue.

queue_first(q)

  Returns the first entry in the queue.

queue_next(q)

  Returns the entry after an item in the queue.

queue_last(q)

  Returns the last entry in the queue.

queue_prev(q)

  Returns the entry before an item in the queue.

queue_end(q, qe)

  Tests whether a new entry is really the end of the queue.

queue_empty(q)

  Tests whether a queue is empty.

queue_enter(q, elt, type, field)

  Insert a new element at the tail of the queue.

queue_enter_first(head, elt, type, field)

  Insert a new element at the head of the queue.

queue_enter_before(head, nelt, elt, type, field)

  Insert a new element before the indicated element.

queue_enter_after(head, pelt, elt, type, field)

  Insert a new element after the indicated element.

queue_remove(head, elt, type, field)

  Remove an arbitrary item from the queue.

queue_remove_first(head, entry, type, field)

  Remove and return the entry at the head of the queue.

queue_remove_last(head, entry, type, field)

  Remove and return the entry at the tail of the queue.

queue_assign(to, from, type, field)

  Move an element in a queue to a new piece of memory.

queue_iterate(head, elt, type, field)

  Iterate over each item in the queue. Generates a 'for' loop, setting elt to each item in turn (by reference).

This header file is taken from CMU's Mach kernel.