1/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
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 <https://www.gnu.org/licenses/>. */
17
18#ifndef _EXIT_H
19#define _EXIT_H 1
20
21#include <stdbool.h>
22#include <stdint.h>
23#include <libc-lock.h>
24
25enum
26{
27 ef_free, /* `ef_free' MUST be zero! */
28 ef_us,
29 ef_on,
30 ef_at,
31 ef_cxa
32};
33
34struct exit_function
35 {
36 /* `flavour' should be of type of the `enum' above but since we need
37 this element in an atomic operation we have to use `long int'. */
38 long int flavor;
39 union
40 {
41 void (*at) (void);
42 struct
43 {
44 void (*fn) (int status, void *arg);
45 void *arg;
46 } on;
47 struct
48 {
49 void (*fn) (void *arg, int status);
50 void *arg;
51 void *dso_handle;
52 } cxa;
53 } func;
54 };
55struct exit_function_list
56 {
57 struct exit_function_list *next;
58 size_t idx;
59 struct exit_function fns[32];
60 };
61
62extern struct exit_function_list *__exit_funcs attribute_hidden;
63extern struct exit_function_list *__quick_exit_funcs attribute_hidden;
64extern uint64_t __new_exitfn_called attribute_hidden;
65
66/* True once all registered atexit/at_quick_exit/onexit handlers have been
67 called */
68extern bool __exit_funcs_done attribute_hidden;
69
70/* This lock protects __exit_funcs, __quick_exit_funcs, __exit_funcs_done
71 and __new_exitfn_called globals against simultaneous access from
72 atexit/on_exit/at_quick_exit in multiple threads, and also from
73 simultaneous access while another thread is in the middle of calling
74 exit handlers. See BZ#14333. Note: for lists, the entire list, and
75 each associated entry in the list, is protected for all access by this
76 lock. */
77__libc_lock_define (extern, __exit_funcs_lock);
78
79
80extern struct exit_function *__new_exitfn (struct exit_function_list **listp)
81 attribute_hidden;
82
83extern void __run_exit_handlers (int status,
84 struct exit_function_list **listp,
85 bool run_list_atexit, bool run_dtors)
86 attribute_hidden __attribute__ ((__noreturn__));
87
88extern int __internal_atexit (void (*func) (void *), void *arg, void *d,
89 struct exit_function_list **listp)
90 attribute_hidden;
91extern int __cxa_at_quick_exit (void (*func) (void *), void *d);
92
93
94#endif /* exit.h */
95