gdb/osf-share/cma_list.h

   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
  72 typedef 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