1 /* Copyright (C) 1999,2001,2002,2005,2006,2009 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, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 #include <bits/libc-lock.h>
32 __internal_atexit (void (*func) (void *), void *arg, void *d,
33 struct exit_function_list **listp)
35 struct exit_function *new = __new_exitfn (listp);
43 new->func.cxa.fn = (void (*) (void *, int)) func;
44 new->func.cxa.arg = arg;
45 new->func.cxa.dso_handle = d;
46 atomic_write_barrier ();
52 /* Register a function to be called by exit or when a shared library
53 is unloaded. This function is only called from code generated by
56 __cxa_atexit (void (*func) (void *), void *arg, void *d)
58 return __internal_atexit (func, arg, d, &__exit_funcs);
63 /* We change global data, so we need locking. */
64 __libc_lock_define_initialized (static, lock)
67 static struct exit_function_list initial;
68 struct exit_function_list *__exit_funcs = &initial;
69 uint64_t __new_exitfn_called;
71 struct exit_function *
72 __new_exitfn (struct exit_function_list **listp)
74 struct exit_function_list *p = NULL;
75 struct exit_function_list *l;
76 struct exit_function *r = NULL;
79 __libc_lock_lock (lock);
81 for (l = *listp; l != NULL; p = l, l = l->next)
83 for (i = l->idx; i > 0; --i)
84 if (l->fns[i - 1].flavor != ef_free)
90 /* This block is completely unused. */
94 if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
96 /* The last entry in a block is used. Use the first entry in
97 the previous block if it exists. Otherwise create a new one. */
101 p = (struct exit_function_list *)
102 calloc (1, sizeof (struct exit_function_list));
118 /* There is more room in the block. */
123 /* Mark entry as used, but we don't know the flavor now. */
127 ++__new_exitfn_called;
130 __libc_lock_unlock (lock);