Source to kernserv/queue.h
/*
* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
* Reserved. This file contains Original Code and/or Modifications of
* Original Code as defined in and that are subject to the Apple Public
* Source License Version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. Please obtain a copy of the
* License at http://www.apple.com/publicsource and read it before using
* this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License."
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
* Mach Operating System
* Copyright (c) 1989 Carnegie-Mellon University
* Copyright (c) 1988 Carnegie-Mellon University
* Copyright (c) 1987 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
/*
* File: queue.h
*
* Type definitions for generic queues.
*/
#ifdef KERNEL_PRIVATE
#warning Obsolete header file: <kernserv/queue.h>, use <kern/queue.h> \
instead; or better yet, just say no!!
#import <kern/queue.h>
#else /* KERNEL_PRIVATE */
#ifndef _KERN_QUEUE_H_
#define _KERN_QUEUE_H_
#import <mach/machine/vm_types.h>
#import <kernserv/lock.h>
#import <kernserv/macro_help.h>
/*
* Queue of abstract objects. Queue is maintained
* within that object.
*
* Supports fast removal from within the queue.
*
* How to declare a queue of elements of type "foo_t":
* In the "*foo_t" type, you must have a field of
* type "queue_chain_t" to hold together this queue.
* There may be more than one chain through a
* "foo_t", for use by different queues.
*
* Declare the queue as a "queue_t" type.
*
* Elements of the queue (of type "foo_t", that is)
* are referred to by reference, and cast to type
* "queue_entry_t" within this module.
*/
/*
* A generic doubly-linked list (queue).
*/
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;
/*
* enqueue puts "elt" on the "queue".
* dequeue returns the first element in the "queue".
* remqueue removes the specified "elt" from the specified "queue".
*/
#define enqueue(queue,elt) enqueue_tail(queue, elt)
#define dequeue(queue) dequeue_head(queue)
extern void enqueue_head();
extern void enqueue_tail();
extern queue_entry_t dequeue_head();
extern queue_entry_t dequeue_tail();
extern void remqueue();
/*
* Macro: queue_init
* Function:
* Initialize the given queue.
* Header:
* void queue_init(q)
* queue_t q; \* MODIFIED *\
*/
#define queue_init(q) ((q)->next = (q)->prev = q)
/*
* Macro: queue_first
* Function:
* Returns the first entry in the queue,
* Header:
* queue_entry_t queue_first(q)
* queue_t q; \* IN *\
*/
#define queue_first(q) ((q)->next)
/*
* Macro: queue_next
* Header:
* queue_entry_t queue_next(qc)
* queue_t qc;
*/
#define queue_next(qc) ((qc)->next)
/*
* Macro: queue_end
* Header:
* boolean_t queue_end(q, qe)
* queue_t q;
* queue_entry_t qe;
*/
#define queue_end(q, qe) ((q) == (qe))
#define queue_empty(q) queue_end((q), queue_first(q))
/*
* Macro: queue_enter
* Header:
* void queue_enter(q, elt, type, field)
* queue_t q;
* <type> elt;
* <type> is what's in our queue
* <field> is the chain field in (*<type>)
*/
#define queue_enter(head, elt, type, field) \
MACRO_BEGIN \
if (queue_empty((head))) { \
(head)->next = (queue_entry_t) elt; \
(head)->prev = (queue_entry_t) elt; \
(elt)->field.next = head; \
(elt)->field.prev = head; \
} \
else { \
register queue_entry_t prev; \
\
prev = (head)->prev; \
(elt)->field.prev = prev; \
(elt)->field.next = head; \
(head)->prev = (queue_entry_t)(elt); \
((type)prev)->field.next = (queue_entry_t)(elt);\
} \
MACRO_END
/*
* Macro: queue_field [internal use only]
* Function:
* Find the queue_chain_t (or queue_t) for the
* given element (thing) in the given queue (head)
*/
#define queue_field(head, thing, type, field) \
(((head) == (thing)) ? (head) : &((type)(thing))->field)
/*
* Macro: queue_remove
* Header:
* void queue_remove(q, qe, type, field)
* arguments as in queue_enter
*/
#define queue_remove(head, elt, type, field) \
MACRO_BEGIN \
register queue_entry_t next, prev; \
\
next = (elt)->field.next; \
prev = (elt)->field.prev; \
\
queue_field((head), next, type, field)->prev = prev; \
queue_field((head), prev, type, field)->next = next; \
MACRO_END
/*
* Macro: queue_assign
*/
#define queue_assign(to, from, type, field) \
MACRO_BEGIN \
((type)((from)->prev))->field.next = (to); \
((type)((from)->next))->field.prev = (to); \
*to = *from; \
MACRO_END
#define queue_remove_first(h, e, t, f) \
MACRO_BEGIN \
e = (t) queue_first((h)); \
queue_remove((h), (e), t, f); \
MACRO_END
#define queue_remove_last(h, e, t, f) \
MACRO_BEGIN \
e = (t) queue_last((h)); \
queue_remove((h), (e), t, f); \
MACRO_END
/*
* Macro: queue_enter_first
* Header:
* void queue_enter_first(q, elt, type, field)
* queue_t q;
* <type> elt;
* <type> is what's in our queue
* <field> is the chain field in (*<type>)
*/
#define queue_enter_first(head, elt, type, field) \
MACRO_BEGIN \
if (queue_empty((head))) { \
(head)->next = (queue_entry_t) elt; \
(head)->prev = (queue_entry_t) elt; \
(elt)->field.next = head; \
(elt)->field.prev = head; \
} \
else { \
register queue_entry_t next; \
\
next = (head)->next; \
(elt)->field.prev = head; \
(elt)->field.next = next; \
(head)->next = (queue_entry_t)(elt); \
((type)next)->field.prev = (queue_entry_t)(elt);\
} \
MACRO_END
/*
* Macro: queue_last
* Function:
* Returns the last entry in the queue,
* Header:
* queue_entry_t queue_last(q)
* queue_t q; \* IN *\
*/
#define queue_last(q) ((q)->prev)
/*
* Macro: queue_prev
* Header:
* queue_entry_t queue_prev(qc)
* queue_t qc;
*/
#define queue_prev(qc) ((qc)->prev)
/*
* Macro: queue_iterate
* Function:
* iterate over each item in the queue.
* Generates a 'for' loop, setting elt to
* each item in turn (by reference).
* Header:
* queue_iterate(q, elt, type, field)
* queue_t q;
* <type> elt;
* <type> is what's in our queue
* <field> is the chain field in (*<type>)
*/
#define queue_iterate(head, elt, type, field) \
for ((elt) = (type) queue_first(head); \
!queue_end((head), (queue_entry_t)(elt)); \
(elt) = (type) queue_next(&(elt)->field))
#ifdef KERNEL
/*
* Define macros for queues with locks.
*/
struct mpqueue_head {
struct queue_entry head; /* header for queue */
simple_lock_data_t lock; /* lock for queue */
};
typedef struct mpqueue_head mpqueue_head_t;
#define round_mpq(size) (size)
#define mpqueue_init(q) \
MACRO_BEGIN \
queue_init(&(q)->head); \
simple_lock_init(&(q)->lock); \
MACRO_END
#define mpenqueue_tail(q, elt) \
MACRO_BEGIN \
simple_lock(&(q)->lock); \
enqueue_tail(&(q)->head, elt); \
simple_unlock(&(q)->lock); \
MACRO_END
#define mpdequeue_head(q, elt) \
MACRO_BEGIN \
simple_lock(&(q)->lock); \
if (queue_empty(&(q)->head)) \
*(elt) = 0; \
else \
*(elt) = dequeue_head(&(q)->head); \
simple_unlock(&(q)->lock); \
MACRO_END
#endif /* KERNEL */
#endif /* _KERN_QUEUE_H_ */
#endif /* KERNEL_PRIVATE */