diff --git a/library/std/src/thread/current.rs b/library/std/src/thread/current.rs index 414711298f047..b5860e24936e6 100644 --- a/library/std/src/thread/current.rs +++ b/library/std/src/thread/current.rs @@ -130,12 +130,32 @@ pub(super) fn set_current(thread: Thread) -> Result<(), Thread> { Ok(()) } -/// Gets the id of the thread that invokes it. +/// Gets the unique identifier of the thread which invokes it. +/// +/// Calling this function may be more efficient than accessing the current +/// thread id through the current thread handle. i.e. `thread::current().id()`. /// /// This function will always succeed, will always return the same value for /// one thread and is guaranteed not to call the global allocator. +/// +/// # Examples +/// +/// ``` +/// #![feature(current_thread_id)] +/// +/// use std::thread; +/// +/// let other_thread = thread::spawn(|| { +/// thread::current_id() +/// }); +/// +/// let other_thread_id = other_thread.join().unwrap(); +/// assert!(thread::current_id() != other_thread_id); +/// ``` #[inline] -pub(crate) fn current_id() -> ThreadId { +#[must_use] +#[unstable(feature = "current_thread_id", issue = "none")] +pub fn current_id() -> ThreadId { // If accessing the persistent thread ID takes multiple TLS accesses, try // to retrieve it from the current thread handle, which will only take one // TLS access. diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs index 26b2fb4472436..818fc575d8c27 100644 --- a/library/std/src/thread/mod.rs +++ b/library/std/src/thread/mod.rs @@ -183,7 +183,9 @@ mod current; #[stable(feature = "rust1", since = "1.0.0")] pub use current::current; -pub(crate) use current::{current_id, current_or_unnamed, drop_current}; +#[unstable(feature = "current_thread_id", issue = "none")] +pub use current::current_id; +pub(crate) use current::{current_or_unnamed, drop_current}; use current::{set_current, try_with_current}; mod spawnhook;