/* Copyright (C) 1991, 1996 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <bits/libc-lock.h> #include <stdlib.h> #include "exit.h" /* Register FUNC to be executed by `exit'. */ int atexit (void (*func) (void)) { struct exit_function *new = __new_exitfn (); if (new == NULL) return -1; new->flavor = ef_at; new->func.at = func; return 0; } /* We change global data, so we need locking. */ __libc_lock_define_initialized (static, lock) static struct exit_function_list fnlist = { NULL, 0, }; struct exit_function_list *__exit_funcs = &fnlist; struct exit_function * __new_exitfn (void) { struct exit_function_list *l; size_t i = 0; __libc_lock_lock (lock); for (l = __exit_funcs; l != NULL; l = l->next) { for (i = 0; i < l->idx; ++i) if (l->fns[i].flavor == ef_free) break; if (i < l->idx) break; if (l->idx < sizeof (l->fns) / sizeof (l->fns[0])) { i = l->idx++; break; } } if (l == NULL) { l = (struct exit_function_list *) malloc (sizeof (struct exit_function_list)); if (l != NULL) { l->next = __exit_funcs; __exit_funcs = l; l->idx = 1; i = 0; } } /* Mark entry as used, but we don't know the flavor now. */ if (l != NULL) l->fns[i].flavor = ef_us; __libc_lock_unlock (lock); return l == NULL ? NULL : &l->fns[i]; }