1 /* Copyright (C) 1999-2013 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
21 #include <bits/libc-lock.h>
31 __internal_atexit (void (*func) (void *), void *arg, void *d,
32 struct exit_function_list **listp)
34 struct exit_function *new = __new_exitfn (listp);
42 new->func.cxa.fn = (void (*) (void *, int)) func;
43 new->func.cxa.arg = arg;
44 new->func.cxa.dso_handle = d;
45 atomic_write_barrier ();
51 /* Register a function to be called by exit or when a shared library
52 is unloaded. This function is only called from code generated by
55 __cxa_atexit (void (*func) (void *), void *arg, void *d)
57 return __internal_atexit (func, arg, d, &__exit_funcs);
62 /* We change global data, so we need locking. */
63 __libc_lock_define_initialized (static, lock)
66 static struct exit_function_list initial;
67 struct exit_function_list *__exit_funcs = &initial;
68 uint64_t __new_exitfn_called;
70 struct exit_function *
71 __new_exitfn (struct exit_function_list **listp)
73 struct exit_function_list *p = NULL;
74 struct exit_function_list *l;
75 struct exit_function *r = NULL;
78 __libc_lock_lock (lock);
80 for (l = *listp; l != NULL; p = l, l = l->next)
82 for (i = l->idx; i > 0; --i)
83 if (l->fns[i - 1].flavor != ef_free)
89 /* This block is completely unused. */
93 if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
95 /* The last entry in a block is used. Use the first entry in
96 the previous block if it exists. Otherwise create a new one. */
100 p = (struct exit_function_list *)
101 calloc (1, sizeof (struct exit_function_list));
117 /* There is more room in the block. */
122 /* Mark entry as used, but we don't know the flavor now. */
126 ++__new_exitfn_called;
129 __libc_lock_unlock (lock);