Auto merge of #102919 - luojia65:update-stdarch, r=Amanieu

[rust.git] / library / core / src / sync / atomic.rs

diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
index 3c96290fc537e19bbe1e2b400a5eabf13ece5a0c..6c70517d965b2b08aa6edd29726d3ec37f18b269 100644 (file)
--- a/library/core/src/sync/atomic.rs
+++ b/library/core/src/sync/atomic.rs
@@ -955,6 +955,14 @@ pub fn as_mut_ptr(&self) -> *mut bool {
     /// **Note:** This method is only available on platforms that support atomic
     /// operations on `u8`.
     ///
+    /// # Considerations
+    ///
+    /// This method is not magic;  it is not provided by the hardware.
+    /// It is implemented in terms of [`AtomicBool::compare_exchange_weak`], and suffers from the same drawbacks.
+    /// In particular, this method will not circumvent the [ABA Problem].
+    ///
+    /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem
+    ///
     /// # Examples
     ///
     /// ```rust
@@ -1422,6 +1430,14 @@ pub fn compare_exchange_weak(
     /// **Note:** This method is only available on platforms that support atomic
     /// operations on pointers.
     ///
+    /// # Considerations
+    ///
+    /// This method is not magic;  it is not provided by the hardware.
+    /// It is implemented in terms of [`AtomicPtr::compare_exchange_weak`], and suffers from the same drawbacks.
+    /// In particular, this method will not circumvent the [ABA Problem].
+    ///
+    /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem
+    ///
     /// # Examples
     ///
     /// ```rust
@@ -2510,6 +2526,16 @@ pub fn fetch_xor(&self, val: $int_type, order: Ordering) -> $int_type {
             /// **Note**: This method is only available on platforms that support atomic operations on
             #[doc = concat!("[`", $s_int_type, "`].")]
             ///
+            /// # Considerations
+            ///
+            /// This method is not magic;  it is not provided by the hardware.
+            /// It is implemented in terms of
+            #[doc = concat!("[`", stringify!($atomic_type), "::compare_exchange_weak`],")]
+            /// and suffers from the same drawbacks.
+            /// In particular, this method will not circumvent the [ABA Problem].
+            ///
+            /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem
+            ///
             /// # Examples
             ///
             /// ```rust