exit.h (2856B) - Raw
1 /* Copyright (C) 1991-2025 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 25 enum 26 { 27 ef_free, /* `ef_free' MUST be zero! */ 28 ef_us, 29 ef_on, 30 ef_at, 31 ef_cxa 32 }; 33 34 struct 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 }; 55 struct exit_function_list 56 { 57 struct exit_function_list *next; 58 size_t idx; 59 struct exit_function fns[32]; 60 }; 61 62 extern struct exit_function_list *__exit_funcs attribute_hidden; 63 extern struct exit_function_list *__quick_exit_funcs attribute_hidden; 64 extern uint64_t __new_exitfn_called attribute_hidden; 65 66 /* True once all registered atexit/at_quick_exit/onexit handlers have been 67 called */ 68 extern 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 80 extern struct exit_function *__new_exitfn (struct exit_function_list **listp) 81 attribute_hidden; 82 83 extern 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 88 extern int __internal_atexit (void (*func) (void *), void *arg, void *d, 89 struct exit_function_list **listp) 90 attribute_hidden; 91 extern int __cxa_at_quick_exit (void (*func) (void *), void *d); 92 93 94 #endif /* exit.h */