1use crate::alloc::System;
2use crate::cell::RefCell;
3use crate::sys::thread_local::guard;
4
5#[thread_local]
6static DTORS: RefCell<Vec<(*mut u8, unsafe extern "C" fn(*mut u8)), System>> =
7 RefCell::new(Vec::new_in(alloc:System));
8
9pub unsafe fn register(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
10 let Ok(mut dtors: RefMut<'_, Vec<(*mut u8, …), …>>) = DTORS.try_borrow_mut() else {
11 rtabort!("the System allocator may not use TLS with destructors")
12 };
13 guard::enable();
14 dtors.push((t, dtor));
15}
16
17/// The [`guard`] module contains platform-specific functions which will run this
18/// function on thread exit if [`guard::enable`] has been called.
19///
20/// # Safety
21///
22/// May only be run on thread exit to guarantee that there are no live references
23/// to TLS variables while they are destroyed.
24pub unsafe fn run() {
25 loop {
26 let mut dtors: RefMut<'_, Vec<(*mut u8, …), …>> = DTORS.borrow_mut();
27 match dtors.pop() {
28 Some((t: *mut u8, dtor: unsafe fn(*mut u8))) => {
29 drop(dtors);
30 unsafe {
31 dtor(t);
32 }
33 }
34 None => {
35 // Free the list memory.
36 *dtors = Vec::new_in(alloc:System);
37 break;
38 }
39 }
40 }
41}
42