diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs index e29c28f3c7ec2..fd57d65cafc3e 100644 --- a/library/std/src/thread/mod.rs +++ b/library/std/src/thread/mod.rs @@ -1503,6 +1503,52 @@ impl Thread { self.inner.name.as_str() } + /// Consumes the `Thread`, returning a raw pointer. + /// + /// To avoid a memory leak the pointer must be converted + /// back into a `Thread` using [`Thread::from_raw`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(thread_raw)] + /// + /// use std::thread::{self, Thread}; + /// + /// let thread = thread::current(); + /// let id = thread.id(); + /// let ptr = Thread::into_raw(thread); + /// unsafe { + /// assert_eq!(Thread::from_raw(ptr).id(), id); + /// } + /// ``` + #[unstable(feature = "thread_raw", issue = "97523")] + pub fn into_raw(self) -> *const () { + Arc::into_raw(Pin::into_inner(self.inner)) as *const () + } + + /// Constructs a `Thread` from a raw pointer. + /// + /// The raw pointer must have been previously returned + /// by a call to [`Thread::into_raw`]. + /// + /// # Safety + /// + /// This function is unsafe because improper use may lead + /// to memory unsafety, even if the returned `Thread` is never + /// accessed. + /// + /// Creating a `Thread` from a pointer other than one returned + /// from [`Thread::into_raw`] is **undefined behavior**. + /// + /// Calling this function twice on the same raw pointer can lead + /// to a double-free if both `Thread` instances are dropped. + #[unstable(feature = "thread_raw", issue = "97523")] + pub unsafe fn from_raw(ptr: *const ()) -> Thread { + // SAFETY: upheld by caller + unsafe { Thread { inner: Pin::new_unchecked(Arc::from_raw(ptr as *const Inner)) } } + } + fn cname(&self) -> Option<&CStr> { self.inner.name.as_cstr() }