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/* Hook for making the close() function extensible.
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Copyright (C) 2009, 2010 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2009.
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This program is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published
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by the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "close-hook.h"
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/* Currently, this entire code is only needed for the handling of sockets
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on native Windows platforms. */
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/* The first and last link in the doubly linked list.
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Initially the list is empty. */
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static struct close_hook anchor = { &anchor, &anchor, NULL };
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execute_close_hooks (int fd, const struct close_hook *remaining_list)
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if (remaining_list == &anchor)
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/* End of list reached. */
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return remaining_list->private_fn (fd, remaining_list->private_next);
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execute_all_close_hooks (int fd)
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return execute_close_hooks (fd, anchor.private_next);
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register_close_hook (close_hook_fn hook, struct close_hook *link)
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if (link->private_next == NULL && link->private_prev == NULL)
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/* Add the link to the doubly linked list. */
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link->private_next = anchor.private_next;
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link->private_prev = &anchor;
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link->private_fn = hook;
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anchor.private_next->private_prev = link;
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anchor.private_next = link;
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/* The link is already in use. */
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if (link->private_fn != hook)
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unregister_close_hook (struct close_hook *link)
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struct close_hook *next = link->private_next;
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struct close_hook *prev = link->private_prev;
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if (next != NULL && prev != NULL)
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/* The link is in use. Remove it from the doubly linked list. */
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prev->private_next = next;
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next->private_prev = prev;
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/* Clear the link, to mark it unused. */
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link->private_next = NULL;
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link->private_prev = NULL;
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link->private_fn = NULL;