os/sync/
up.rs

1//! Uniprocessor interior mutability primitives
2
3use core::cell::{RefCell, RefMut};
4
5/// Wrap a static data structure inside it so that we are
6/// able to access it without any `unsafe`.
7///
8/// We should only use it in uniprocessor.
9///
10/// In order to get mutable reference of inner data, call
11/// `exclusive_access`.
12pub struct UPSafeCell<T> {
13    /// inner data
14    inner: RefCell<T>,
15}
16
17unsafe impl<T> Sync for UPSafeCell<T> {}
18
19impl<T> UPSafeCell<T> {
20    /// User is responsible to guarantee that inner struct is only used in
21    /// uniprocessor.
22    pub unsafe fn new(value: T) -> Self {
23        Self {
24            inner: RefCell::new(value),
25        }
26    }
27    /// Exclusive access inner data in UPSafeCell. Panic if the data has been borrowed.
28    pub fn exclusive_access(&self) -> RefMut<'_, T> {
29        self.inner.borrow_mut()
30    }
31}
os/sync/up.rs

os/sync/
up.rs
