freebsd-nq/sys/coda/coda_kernel.h

67 lines
2.4 KiB
C

/*-
*
* Coda: an Experimental Distributed File System
* Release 3.1
*
* Copyright (c) 1987-1998 Carnegie Mellon University
* All Rights Reserved
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation, and
* that credit is given to Carnegie Mellon University in all documents
* and publicity pertaining to direct or indirect use of this code or its
* derivatives.
*
* CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
* SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
* FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
* DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
* RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
* ANY DERIVATIVE WORK.
*
* Carnegie Mellon encourages users of this software to return any
* improvements or extensions that they make, and to grant Carnegie
* Mellon the rights to redistribute these changes without encumbrance.
*
* @(#) src/sys/coda/coda_kernel.h,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
* $FreeBSD$
*
*/
/* Macros to manipulate the queue */
#ifndef INIT_QUEUE
struct queue {
struct queue *forw, *back;
};
#define INIT_QUEUE(head) \
do { \
(head).forw = (struct queue *)&(head); \
(head).back = (struct queue *)&(head); \
} while (0)
#define GETNEXT(head) (head).forw
#define EMPTY(head) ((head).forw == &(head))
#define EOQ(el, head) ((struct queue *)(el) == (struct queue *)&(head))
#define INSQUE(el, head) \
do { \
(el).forw = ((head).back)->forw; \
(el).back = (head).back; \
((head).back)->forw = (struct queue *)&(el); \
(head).back = (struct queue *)&(el); \
} while (0)
#define REMQUE(el) \
do { \
((el).forw)->back = (el).back; \
(el).back->forw = (el).forw; \
} while (0)
#endif