1/*
2 * (c) Copyright 1990-1996 OPEN SOFTWARE FOUNDATION, INC.
3 * (c) Copyright 1990-1996 HEWLETT-PACKARD COMPANY
4 * (c) Copyright 1990-1996 DIGITAL EQUIPMENT CORPORATION
5 * (c) Copyright 1991, 1992 Siemens-Nixdorf Information Systems
6 * To anyone who acknowledges that this file is provided "AS IS" without
7 * any express or implied warranty: permission to use, copy, modify, and
8 * distribute this file for any purpose is hereby granted without fee,
9 * provided that the above copyright notices and this notice appears in
10 * all source code copies, and that none of the names listed above be used
11 * in advertising or publicity pertaining to distribution of the software
12 * without specific, written prior permission.  None of these organizations
13 * makes any representations about the suitability of this software for
14 * any purpose.
15 */
16/*
17 *	Header file for generic list functions operating on singly linked
18 *	null-terminated lists.  Items may not be REMOVED from the list!  The
19 *	intent is that the list can be traversed (for read-only operations)
20 *	without locking, since insertion is "safe" (though not truely
21 *	atomic).  THIS ASSUMES THAT THE HARDWARE MAKES WRITES VISIBLE TO READS
22 *	IN THE ORDER IN WHICH THEY OCCURRED!  WITHOUT SUCH READ/WRITE
23 *	ORDERING, IT MAY BE NECESSARY TO INSERT "BARRIERS" TO PRODUCE THE
24 *	REQUIRED VISIBILITY!
25 */
26
27#ifndef CMA_LIST
28#define CMA_LIST
29
30/*
31 *  INCLUDE FILES
32 */
33
34#include <cma.h>
35
36/*
37 * CONSTANTS AND MACROS
38 */
39
40#define cma__c_null_list	((cma__t_list *)cma_c_null_ptr)
41
42/*
43 * Test whether a list is empty.  Return cma_c_true if so, else
44 * cma_c_false.
45 */
46#define cma__list_empty(head)	((head)->link == cma__c_null_list)
47
48/*
49 * Initialize a queue header to empty.
50 */
51#define cma__list_init(head)	(void)((head)->link = cma__c_null_list)
52
53/*
54 * Insert an element in a list following the specified item (or at the
55 * beginning of the list if "list" is the list head).  NOTE: insertion
56 * operations should be interlocked by the caller!
57 */
58#define cma__list_insert(element,list)    (void)(	\
59    (element)->link		= (list)->link,		\
60    (list)->link		= (element))
61
62/*
63 * Return the next item in a list (or the first, if the address is of the
64 * list header)
65 */
66#define cma__list_next(element)    ((element)->link)
67
68/*
69 * TYPEDEFS
70 */
71
72typedef struct CMA__T_LIST {
73    struct CMA__T_LIST	*link;		/* Forward link */
74    } cma__t_list;
75
76/*
77 *  GLOBAL DATA
78 */
79
80/*
81 * INTERNAL INTERFACES
82 */
83
84#endif
85