| /* Copyright (C) 1999-2018 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <assert.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| |
| #include <libc-lock.h> |
| #include "exit.h" |
| #include <sysdep.h> |
| |
| #undef __cxa_atexit |
| |
| /* See concurrency notes in stdlib/exit.h where this lock is declared. */ |
| __libc_lock_define_initialized (, __exit_funcs_lock) |
| |
| |
| int |
| attribute_hidden |
| __internal_atexit (void (*func) (void *), void *arg, void *d, |
| struct exit_function_list **listp) |
| { |
| struct exit_function *new; |
| |
| __libc_lock_lock (__exit_funcs_lock); |
| new = __new_exitfn (listp); |
| |
| if (new == NULL) |
| { |
| __libc_lock_unlock (__exit_funcs_lock); |
| return -1; |
| } |
| |
| #ifdef PTR_MANGLE |
| PTR_MANGLE (func); |
| #endif |
| new->func.cxa.fn = (void (*) (void *, int)) func; |
| new->func.cxa.arg = arg; |
| new->func.cxa.dso_handle = d; |
| new->flavor = ef_cxa; |
| __libc_lock_unlock (__exit_funcs_lock); |
| return 0; |
| } |
| |
| |
| /* Register a function to be called by exit or when a shared library |
| is unloaded. This function is only called from code generated by |
| the C++ compiler. */ |
| int |
| __cxa_atexit (void (*func) (void *), void *arg, void *d) |
| { |
| return __internal_atexit (func, arg, d, &__exit_funcs); |
| } |
| libc_hidden_def (__cxa_atexit) |
| |
| |
| static struct exit_function_list initial; |
| struct exit_function_list *__exit_funcs = &initial; |
| uint64_t __new_exitfn_called; |
| |
| /* Must be called with __exit_funcs_lock held. */ |
| struct exit_function * |
| __new_exitfn (struct exit_function_list **listp) |
| { |
| struct exit_function_list *p = NULL; |
| struct exit_function_list *l; |
| struct exit_function *r = NULL; |
| size_t i = 0; |
| |
| if (__exit_funcs_done) |
| /* Exit code is finished processing all registered exit functions, |
| therefore we fail this registration. */ |
| return NULL; |
| |
| for (l = *listp; l != NULL; p = l, l = l->next) |
| { |
| for (i = l->idx; i > 0; --i) |
| if (l->fns[i - 1].flavor != ef_free) |
| break; |
| |
| if (i > 0) |
| break; |
| |
| /* This block is completely unused. */ |
| l->idx = 0; |
| } |
| |
| if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0])) |
| { |
| /* The last entry in a block is used. Use the first entry in |
| the previous block if it exists. Otherwise create a new one. */ |
| if (p == NULL) |
| { |
| assert (l != NULL); |
| p = (struct exit_function_list *) |
| calloc (1, sizeof (struct exit_function_list)); |
| if (p != NULL) |
| { |
| p->next = *listp; |
| *listp = p; |
| } |
| } |
| |
| if (p != NULL) |
| { |
| r = &p->fns[0]; |
| p->idx = 1; |
| } |
| } |
| else |
| { |
| /* There is more room in the block. */ |
| r = &l->fns[i]; |
| l->idx = i + 1; |
| } |
| |
| /* Mark entry as used, but we don't know the flavor now. */ |
| if (r != NULL) |
| { |
| r->flavor = ef_us; |
| ++__new_exitfn_called; |
| } |
| |
| return r; |
| } |