Struct mycelium_util::sync::cell::UnsafeCell

pub struct UnsafeCell<T> { /* private fields */ }

Available on non-loom only.

A variant of core::cell::UnsafeCell that may be checked when Loom model checking is enabled.

This type is similar to core::cell::UnsafeCell, except when the cfg(loom) cfg flag is enabled, it is replaced with a variant that participates in Loom model checking. See loom::cell::UnsafeCell for details on this.

When cfg(loom) is not set, this type is essentially a core::cell::UnsafeCell, but with an API that matches that of the checked Loom cell.

Instead of providing a get() API, this version of UnsafeCell provides with and with_mut. Both functions take a closure in order to track the start and end of the access to the underlying cell.

Implementations

impl<T> UnsafeCell<T>

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

Construct a new instance of UnsafeCell which will wrap the specified value.

pub fn with<F, R>(&self, f: F) -> R

where F: FnOnce(*const T) -> R,

Get an immutable pointer to the wrapped value.

Panics

When running under loom, this function will panic if the access is not valid under the Rust memory model.

pub fn with_mut<F, R>(&self, f: F) -> R

where F: FnOnce(*mut T) -> R,

Get a mutable pointer to the wrapped value.

Panics

When running under loom, this function will panic if the access is not valid under the Rust memory model.

pub fn get(&self) -> ConstPtr<T>

Get an immutable pointer to the wrapped value.

This function returns a ConstPtr guard, which is analogous to a *const T, but tracked by Loom when the cfg(loom) cfg flag is enabled. As long as the returned ConstPtr exists, Loom will consider the cell to be accessed immutably.

This means that any mutable accesses (e.g. calls to with_mut or get_mut) while the returned guard is live will result in a panic.

Panics

This function will panic if the access is not valid under the Rust memory model, if cfg(loom) is enabled.

pub fn get_mut(&self) -> MutPtr<T>

Get a mutable pointer to the wrapped value.

This function returns a MutPtr guard, which is analogous to a *mut T, but tracked by Loom when the cfg(loom) cfg flag is enabled. As long as the returned MutPtr exists, Loom will consider the cell to be accessed mutably.

This means that any concurrent mutable or immutable accesses (e.g. calls to with, with_mut, get, or get_mut) while the returned guard is live will result in a panic.

Panics

This function will panic if the access is not valid under the Rust memory model, if cfg(loom) is enabled.

Trait Implementations

impl<T: Debug> Debug for UnsafeCell<T>

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

Formats the value using the given formatter.