Struct IrqCell 

pub struct IrqCell<T: ?Sized> { /* private fields */ }

Available on crate feature full and non-crate feature use_std only.

An interrupt safe, single-threaded mutable memory location.

This prevents deadlocks between interrupt handlers and main kernel code by keeping interrupts disabled during the time a lock is held.

Implementations

impl<T> IrqCell<T>

pub const fn new(val: T) -> Self

Creates a new IrqCell containing val.

Examples

use kernel_api::sync::IrqCell;

let c = IrqCell::new(5);

impl<T: ?Sized> IrqCell<T>

pub fn lock(&self) -> IrqGuard<'_, T>

Locks the IrqCell, disabling interrupts on the current CPU.

Panics

This function will panic if the IrqCell is already locked by the current CPU.

Examples

use kernel_api::sync::IrqCell;

let c = IrqCell::new(5);
{
    let mut guard = c.lock();
    // Interrupts are now disabled to the end of this block
    *guard = 10;
}

assert_eq!(*c.lock(), 10);

Causing a deadlock will cause a panic:

use kernel_api::sync::IrqCell;

let c = IrqCell::new(5);
let x = c.lock();
let y = c.lock();

pub unsafe fn make_guard_unchecked(&self) -> IrqGuard<'_, T>

Creates a new IrqGuard without checking if the IrqCell is locked.

Safety

The IrqCell must already be logically locked by the current CPU.

Only one IrqGuard must exist at any one time.

pub unsafe fn unlock(&self)

Forcibly unlocks the IrqCell.

This is useful when combined with mem::forget to keep an IrqCell locked without holding onto a IrqGuard.

Safety

The current CPU must logically own an IrqGuard that has discarded in a way that prevents its [Drop] impl being called.

Trait Implementations

impl<T: Debug> Debug for IrqCell<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.