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/* 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]); 
    } 
  } 
}