3 * Coda: an Experimental Distributed File System
6 * Copyright (c) 1987-1998 Carnegie Mellon University
9 * Permission to use, copy, modify and distribute this software and its
10 * documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation, and
14 * that credit is given to Carnegie Mellon University in all documents
15 * and publicity pertaining to direct or indirect use of this code or its
18 * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
19 * SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
20 * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
21 * DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
22 * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
23 * ANY DERIVATIVE WORK.
25 * Carnegie Mellon encourages users of this software to return any
26 * improvements or extensions that they make, and to grant Carnegie
27 * Mellon the rights to redistribute these changes without encumbrance.
29 * @(#) src/sys/coda/coda_kernel.h,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
34 /* Macros to manipulate the queue */
37 struct queue *forw, *back;
40 #define INIT_QUEUE(head) \
42 (head).forw = (struct queue *)&(head); \
43 (head).back = (struct queue *)&(head); \
46 #define GETNEXT(head) (head).forw
48 #define EMPTY(head) ((head).forw == &(head))
50 #define EOQ(el, head) ((struct queue *)(el) == (struct queue *)&(head))
52 #define INSQUE(el, head) \
54 (el).forw = ((head).back)->forw; \
55 (el).back = (head).back; \
56 ((head).back)->forw = (struct queue *)&(el); \
57 (head).back = (struct queue *)&(el); \
62 ((el).forw)->back = (el).back; \
63 (el).back->forw = (el).forw; \