/* Copyright (C) 2004 by Daniel Stenberg et al

 *

 * Permission to use, copy, modify, and distribute this software and its

 * documentation for any purpose and without fee is hereby granted, provided

 * that the above copyright notice appear in all copies and that both that

 * copyright notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in advertising or

 * publicity pertaining to distribution of the software without specific,

 * written prior permission.  M.I.T. makes no representations about the

 * suitability of this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include "ares_setup.h"

#include <assert.h>

#include "ares.h"

#include "ares_private.h"

/*

 * ares_cancel() cancels all ongoing requests/resolves that might be going on

 * on the given channel. It does NOT kill the channel, use ares_destroy() for

 * that.

 */

void ares_cancel(ares_channel channel)

{

  struct query *query;

  struct list_node list_head_copy;

  struct list_node* list_head;

  struct list_node* list_node;

  int i;

  if (!ares__is_list_empty(&(channel->all_queries)))

  {

    /* Swap list heads, so that only those queries which were present on entry

     * into this function are cancelled. New queries added by callbacks of

     * queries being cancelled will not be cancelled themselves.

     */

    list_head = &(channel->all_queries);

    list_head_copy.prev = list_head->prev;

    list_head_copy.next = list_head->next;

    list_head_copy.prev->next = &list_head_copy;

    list_head_copy.next->prev = &list_head_copy;

    list_head->prev = list_head;

    list_head->next = list_head;

    for (list_node = list_head_copy.next; list_node != &list_head_copy; )

    {

      query = list_node->data;

      list_node = list_node->next;  /* since we're deleting the query */

      query->callback(query->arg, ARES_ECANCELLED, 0, NULL, 0);

      ares__free_query(query);

    }

  }

  if (!(channel->flags & ARES_FLAG_STAYOPEN) && ares__is_list_empty(&(channel->all_queries)))

  {

    if (channel->servers)

    {

      for (i = 0; i < channel->nservers; i++)

        ares__close_sockets(channel, &channel->servers[i]);

    }

  }

}