x15/kern/plist.c

/*
 * Copyright (c) 2017 Richard Braun.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Upstream site with license notes :
 * http://git.sceen.net/rbraun/librbraun.git/
 */

#include <kern/list.h>
#include <kern/plist.h>

void
plist_add (struct plist *plist, struct plist_node *pnode)
{
  if (plist_empty (plist))
    {
      list_insert_head (&plist->list, &pnode->node);
      list_insert_head (&plist->prio_list, &pnode->prio_node);
      return;
    }

  struct plist_node *next;
  list_for_each_entry (&plist->prio_list, next, prio_node)
    if (pnode->priority < next->priority)
      break;

  if (list_end (&plist->prio_list, &next->prio_node) ||
      pnode->priority != next->priority)
    list_insert_before (&pnode->prio_node, &next->prio_node);
  else
    list_init (&pnode->prio_node);

  list_insert_before (&pnode->node, &next->node);
}

void
plist_remove (struct plist *plist, struct plist_node *pnode)
{
  if (!list_node_unlinked (&pnode->prio_node))
    {
      struct plist_node *next = list_next_entry (pnode, node);

      if (!list_end (&plist->list, &next->node) &&
          list_node_unlinked (&next->prio_node))
        list_insert_after (&pnode->prio_node, &next->prio_node);

      list_remove (&pnode->prio_node);
    }

  list_remove (&pnode->node);
}