Subversion Repositories HelenOS-historic

Rev

Rev 788 | Rev 1704 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. /*
  2.  * Copyright (C) 2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /**
  30.  * @file    list.c
  31.  * @brief   Functions completing doubly linked circular list implementaion.
  32.  *
  33.  * This file contains some of the functions implementing doubly linked circular lists.
  34.  * However, this ADT is mostly implemented in @ref list.h.
  35.  */
  36.  
  37. #include <adt/list.h>
  38.  
  39. /** Check for membership
  40.  *
  41.  * Check whether link is contained in the list head.
  42.  * The membership is defined as pointer equivalence.
  43.  *
  44.  * @param link Item to look for.
  45.  * @param head List to look in.
  46.  *
  47.  * @return true if link is contained in head, false otherwise.
  48.  *
  49.  */
  50. bool list_member(const link_t *link, const link_t *head)
  51. {
  52.     bool found = false;
  53.     link_t *hlp = head->next;
  54.    
  55.     while (hlp != head) {
  56.         if (hlp == link) {
  57.             found = true;
  58.             break;
  59.         }
  60.         hlp = hlp->next;
  61.     }
  62.    
  63.     return found;
  64. }
  65.  
  66.  
  67. /** Concatenate two lists
  68.  *
  69.  * Concatenate lists head1 and head2, producing a single
  70.  * list head1 containing items from both (in head1, head2
  71.  * order) and empty list head2.
  72.  *
  73.  * @param head1 First list and concatenated output
  74.  * @param head2 Second list and empty output.
  75.  *
  76.  */
  77. void list_concat(link_t *head1, link_t *head2)
  78. {
  79.     if (list_empty(head2))
  80.         return;
  81.  
  82.     head2->next->prev = head1->prev;
  83.     head2->prev->next = head1; 
  84.     head1->prev->next = head2->next;
  85.     head1->prev = head2->prev;
  86.     list_initialize(head2);
  87. }
  88.