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-rw-r--r--stdlib/atexit.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/stdlib/atexit.c b/stdlib/atexit.c
new file mode 100644
index 0000000..a2ab453
--- /dev/null
+++ b/stdlib/atexit.c
@@ -0,0 +1,65 @@
+/* Copyright (C) 1991 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <ansidecl.h>
+#include <stdlib.h>
+#include "exit.h"
+
+
+/* Register FUNC to be executed by `exit'. */
+int
+DEFUN(atexit, (func), void EXFUN((*func), (NOARGS)))
+{
+ struct exit_function *new = __new_exitfn();
+
+ if (new == NULL)
+ return -1;
+
+ new->flavor = ef_at;
+ new->func.at = func;
+ return 0;
+}
+
+
+static struct exit_function_list fnlist = { NULL, 0, };
+struct exit_function_list *__exit_funcs = &fnlist;
+
+struct exit_function *
+DEFUN_VOID(__new_exitfn)
+{
+ register struct exit_function_list *l;
+
+ for (l = __exit_funcs; l != NULL; l = l->next)
+ {
+ register size_t i;
+ for (i = 0; i < l->idx; ++i)
+ if (l->fns[i].flavor == ef_free)
+ return &l->fns[i];
+ if (l->idx < sizeof(l->fns) / sizeof(l->fns[0]))
+ return &l->fns[l->idx++];
+ }
+
+ l = (struct exit_function_list *) malloc(sizeof(struct exit_function_list));
+ if (l == NULL)
+ return NULL;
+ l->next = __exit_funcs;
+ __exit_funcs = l;
+
+ l->idx = 1;
+ return &l->fns[0];
+}