1 files changed, 63 insertions, 0 deletions
diff --git a/src/c-ares/ares_cancel.c b/src/c-ares/ares_cancel.c
new file mode 100644
index 00000000..465cc9e9
--- /dev/null
+++ b/src/c-ares/ares_cancel.c
@@ -0,0 +1,63 @@
+
+/* 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]);
+    }
+  }
+}