Tracking Issue for {Mutex, RwLock}::data_ptr

[jplatte]

Feature gate: #![feature(mutex_data_ptr)], #![feature(rwlock_data_ptr)]

This is a tracking issue for allowing unguarded access to the inner value of a Mutex or RwLock. Previous discussion here: rust-lang/libs-team#531

Public API

// std::sync

impl<T: ?Sized> Mutex<T> {
    pub fn data_ptr(&self) -> *mut T;
}

impl<T: ?Sized> RwLock<T> {
    pub fn data_ptr(&self) -> *mut T;
}

Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

• Implementation: Add data_ptr method to Mutex and RwLock #140369
• Add examples to documentation
• Final comment period (FCP)¹
• Stabilization PR

Unresolved Questions

• Return a LockResult or not?
• Return *mut T like existing APIs (Cell::as_ptr / MaybeUninit::as[_mut]_ptr / Vec::as_ptr / ...) or be more precise and return NonNull<T>?

Footnotes

1. https://std-dev-guide.rust-lang.org/feature-lifecycle/stabilization.html ↩