summaryrefslogtreecommitdiff
path: root/lib/fd-hook.c
diff options
context:
space:
mode:
authorLudovic Courtès <ludo@gnu.org>2011-04-25 23:27:31 +0200
committerLudovic Courtès <ludo@gnu.org>2011-04-25 23:59:37 +0200
commitdd7d0148f221c3180ab6f31c8742aaf4d0e5926a (patch)
tree1aec441600e3d3ff9aec482ba26656e523b90a72 /lib/fd-hook.c
parenteb0ffdd8190bff165120b881ca3e1702be82c83a (diff)
downloadguile-dd7d0148f221c3180ab6f31c8742aaf4d0e5926a.tar.gz
Update Gnulib to v0.0-5158-g7d06b32; remove `strcase' and `version-etc-fsf'.
* m4/gnulib-cache.m4: Remove `strcase' and `version-etc-fsf'. * configure.ac (POTENTIAL_GCC_CFLAGS): Remove `-Wundef'. * libguile/script.c: Don't include <version-etc.h>.
Diffstat (limited to 'lib/fd-hook.c')
-rw-r--r--lib/fd-hook.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/lib/fd-hook.c b/lib/fd-hook.c
new file mode 100644
index 000000000..40fbeeb34
--- /dev/null
+++ b/lib/fd-hook.c
@@ -0,0 +1,116 @@
+/* Hook for making making file descriptor functions close(), ioctl() extensible.
+ Copyright (C) 2009-2011 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2009.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "fd-hook.h"
+
+#include <stdlib.h>
+
+/* Currently, this entire code is only needed for the handling of sockets
+ on native Windows platforms. */
+#if WINDOWS_SOCKETS
+
+/* The first and last link in the doubly linked list.
+ Initially the list is empty. */
+static struct fd_hook anchor = { &anchor, &anchor, NULL, NULL };
+
+int
+execute_close_hooks (const struct fd_hook *remaining_list, gl_close_fn primary,
+ int fd)
+{
+ if (remaining_list == &anchor)
+ /* End of list reached. */
+ return primary (fd);
+ else
+ return remaining_list->private_close_fn (remaining_list->private_next,
+ primary, fd);
+}
+
+int
+execute_all_close_hooks (gl_close_fn primary, int fd)
+{
+ return execute_close_hooks (anchor.private_next, primary, fd);
+}
+
+int
+execute_ioctl_hooks (const struct fd_hook *remaining_list, gl_ioctl_fn primary,
+ int fd, int request, void *arg)
+{
+ if (remaining_list == &anchor)
+ /* End of list reached. */
+ return primary (fd, request, arg);
+ else
+ return remaining_list->private_ioctl_fn (remaining_list->private_next,
+ primary, fd, request, arg);
+}
+
+int
+execute_all_ioctl_hooks (gl_ioctl_fn primary,
+ int fd, int request, void *arg)
+{
+ return execute_ioctl_hooks (anchor.private_next, primary, fd, request, arg);
+}
+
+void
+register_fd_hook (close_hook_fn close_hook, ioctl_hook_fn ioctl_hook, struct fd_hook *link)
+{
+ if (close_hook == NULL)
+ close_hook = execute_close_hooks;
+ if (ioctl_hook == NULL)
+ ioctl_hook = execute_ioctl_hooks;
+
+ if (link->private_next == NULL && link->private_prev == NULL)
+ {
+ /* Add the link to the doubly linked list. */
+ link->private_next = anchor.private_next;
+ link->private_prev = &anchor;
+ link->private_close_fn = close_hook;
+ link->private_ioctl_fn = ioctl_hook;
+ anchor.private_next->private_prev = link;
+ anchor.private_next = link;
+ }
+ else
+ {
+ /* The link is already in use. */
+ if (link->private_close_fn != close_hook
+ || link->private_ioctl_fn != ioctl_hook)
+ abort ();
+ }
+}
+
+void
+unregister_fd_hook (struct fd_hook *link)
+{
+ struct fd_hook *next = link->private_next;
+ struct fd_hook *prev = link->private_prev;
+
+ if (next != NULL && prev != NULL)
+ {
+ /* The link is in use. Remove it from the doubly linked list. */
+ prev->private_next = next;
+ next->private_prev = prev;
+ /* Clear the link, to mark it unused. */
+ link->private_next = NULL;
+ link->private_prev = NULL;
+ link->private_close_fn = NULL;
+ link->private_ioctl_fn = NULL;
+ }
+}
+
+#endif