diff options
| -rw-r--r-- | library/core/src/sync/atomic.rs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs index bac92ef94e7..ae28ec4baa0 100644 --- a/library/core/src/sync/atomic.rs +++ b/library/core/src/sync/atomic.rs @@ -44,8 +44,9 @@ //! The most important aspect of this model is that *data races* are undefined behavior. A data race //! is defined as conflicting non-synchronized accesses where at least one of the accesses is //! non-atomic. Here, accesses are *conflicting* if they affect overlapping regions of memory and at -//! least one of them is a write. They are *non-synchronized* if neither of them *happens-before* -//! the other, according to the happens-before order of the memory model. +//! least one of them is a write. (A `compare_exchange` or `compare_exchange_weak` that does not +//! succeed is not considered a write.) They are *non-synchronized* if neither of them +//! *happens-before* the other, according to the happens-before order of the memory model. //! //! The other possible cause of undefined behavior in the memory model are mixed-size accesses: Rust //! inherits the C++ limitation that non-synchronized conflicting atomic accesses may not partially |