sync: reorder const_new before new_with

tokio/src/sync/once_cell.rs

@@ -132,36 +132,22 @@ impl<T> OnceCell<T> {
  }
  }
 
- /// Creates a new `OnceCell` that contains the provided value, if any.
+ /// Creates a new empty `OnceCell` instance.
  ///
- /// If the `Option` is `None`, this is equivalent to `OnceCell::new`.
+ /// Equivalent to `OnceCell::new`, except that it can be used in static
+ /// variables.
  ///
- /// [`OnceCell::new`]: crate::sync::OnceCell::new
- // Once https:/rust-lang/rust/issues/73255 lands
- // and tokio MSRV is bumped to the rustc version with it stablised,
- // we can made this function available in const context,
- // by creating `Semaphore::const_new_closed`.
- pub fn new_with(value: Option<T>) -> Self {
- if let Some(v) = value {
- OnceCell::from(v)
- } else {
- OnceCell::new()
- }
- }
-
- /// Creates a new `OnceCell` that contains the provided value.
+ /// When using the `tracing` [unstable feature], a `OnceCell` created with
+ /// `const_new` will not be instrumented. As such, it will not be visible
+ /// in [`tokio-console`]. Instead, [`OnceCell::new`] should be used to
+ /// create an instrumented object if that is needed.
  ///
  /// # Example
  ///
- /// When using the `tracing` [unstable feature], a `OnceCell` created with
- /// `const_new_with` will not be instrumented. As such, it will not be
- /// visible in [`tokio-console`]. Instead, [`OnceCell::new_with`] should be
- /// used to create an instrumented object if that is needed.
- ///
  /// ```
  /// use tokio::sync::OnceCell;
  ///
- /// static ONCE: OnceCell<u32> = OnceCell::const_new_with(1);
+ /// static ONCE: OnceCell<u32> = OnceCell::const_new();
  ///
  /// async fn get_global_integer() -> &'static u32 {
  /// ONCE.get_or_init(|| async {
@@ -172,37 +158,51 @@ impl<T> OnceCell<T> {
  /// #[tokio::main]
  /// async fn main() {
  /// let result = get_global_integer().await;
- /// assert_eq!(*result, 1);
+ /// assert_eq!(*result, 2);
  /// }
  /// ```
  ///
  /// [`tokio-console`]: https:/tokio-rs/console
  /// [unstable feature]: crate#unstable-features
  #[cfg(not(all(loom, test)))]
- pub const fn const_new_with(value: T) -> Self {
+ pub const fn const_new() -> Self {
  OnceCell {
- value_set: AtomicBool::new(true),
- value: UnsafeCell::new(MaybeUninit::new(value)),
- semaphore: Semaphore::const_new_closed(),
+ value_set: AtomicBool::new(false),
+ value: UnsafeCell::new(MaybeUninit::uninit()),
+ semaphore: Semaphore::const_new(1),
  }
  }
 
- /// Creates a new empty `OnceCell` instance.
+ /// Creates a new `OnceCell` that contains the provided value, if any.
  ///
- /// Equivalent to `OnceCell::new`, except that it can be used in static
- /// variables.
+ /// If the `Option` is `None`, this is equivalent to `OnceCell::new`.
  ///
- /// When using the `tracing` [unstable feature], a `OnceCell` created with
- /// `const_new` will not be instrumented. As such, it will not be visible
- /// in [`tokio-console`]. Instead, [`OnceCell::new`] should be used to
- /// create an instrumented object if that is needed.
+ /// [`OnceCell::new`]: crate::sync::OnceCell::new
+ // Once https:/rust-lang/rust/issues/73255 lands
+ // and tokio MSRV is bumped to the rustc version with it stablised,
+ // we can made this function available in const context,
+ // by creating `Semaphore::const_new_closed`.
+ pub fn new_with(value: Option<T>) -> Self {
+ if let Some(v) = value {
+ OnceCell::from(v)
+ } else {
+ OnceCell::new()
+ }
+ }
+
+ /// Creates a new `OnceCell` that contains the provided value.
  ///
  /// # Example
  ///
+ /// When using the `tracing` [unstable feature], a `OnceCell` created with
+ /// `const_new_with` will not be instrumented. As such, it will not be
+ /// visible in [`tokio-console`]. Instead, [`OnceCell::new_with`] should be
+ /// used to create an instrumented object if that is needed.
+ ///
  /// ```
  /// use tokio::sync::OnceCell;
  ///
- /// static ONCE: OnceCell<u32> = OnceCell::const_new();
+ /// static ONCE: OnceCell<u32> = OnceCell::const_new_with(1);
  ///
  /// async fn get_global_integer() -> &'static u32 {
  /// ONCE.get_or_init(|| async {
@@ -213,18 +213,18 @@ impl<T> OnceCell<T> {
  /// #[tokio::main]
  /// async fn main() {
  /// let result = get_global_integer().await;
- /// assert_eq!(*result, 2);
+ /// assert_eq!(*result, 1);
  /// }
  /// ```
  ///
  /// [`tokio-console`]: https:/tokio-rs/console
  /// [unstable feature]: crate#unstable-features
  #[cfg(not(all(loom, test)))]
- pub const fn const_new() -> Self {
+ pub const fn const_new_with(value: T) -> Self {
  OnceCell {
- value_set: AtomicBool::new(false),
- value: UnsafeCell::new(MaybeUninit::uninit()),
- semaphore: Semaphore::const_new(1),
+ value_set: AtomicBool::new(true),
+ value: UnsafeCell::new(MaybeUninit::new(value)),
+ semaphore: Semaphore::const_new_closed(),
  }
  }