| #include <stddef.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| #include <limits.h> |
| #include "libc.h" |
| |
| /* Ensure that at least 32 atexit handlers can be registered without malloc */ |
| #define COUNT 32 |
| |
| static struct fl |
| { |
| struct fl *next; |
| void (*f[COUNT])(void *); |
| void *a[COUNT]; |
| } builtin, *head; |
| |
| static int lock[2]; |
| |
| void __funcs_on_exit() |
| { |
| int i; |
| void (*func)(void *), *arg; |
| LOCK(lock); |
| for (; head; head=head->next) for (i=COUNT-1; i>=0; i--) { |
| if (!head->f[i]) continue; |
| func = head->f[i]; |
| arg = head->a[i]; |
| head->f[i] = 0; |
| UNLOCK(lock); |
| func(arg); |
| LOCK(lock); |
| } |
| } |
| |
| void __cxa_finalize(void *dso) |
| { |
| } |
| |
| int __cxa_atexit(void (*func)(void *), void *arg, void *dso) |
| { |
| int i; |
| |
| LOCK(lock); |
| |
| /* Defer initialization of head so it can be in BSS */ |
| if (!head) head = &builtin; |
| |
| /* If the current function list is full, add a new one */ |
| if (head->f[COUNT-1]) { |
| struct fl *new_fl = calloc(sizeof(struct fl), 1); |
| if (!new_fl) { |
| UNLOCK(lock); |
| return -1; |
| } |
| new_fl->next = head; |
| head = new_fl; |
| } |
| |
| /* Append function to the list. */ |
| for (i=0; i<COUNT && head->f[i]; i++); |
| head->f[i] = func; |
| head->a[i] = arg; |
| |
| UNLOCK(lock); |
| return 0; |
| } |
| |
| static void call(void *p) |
| { |
| ((void (*)(void))(uintptr_t)p)(); |
| } |
| |
| int atexit(void (*func)(void)) |
| { |
| return __cxa_atexit(call, (void *)(uintptr_t)func, 0); |
| } |