std::atomic_ref::notify_all - cppreference.com (original) (raw)

| void notify_all() const noexcept; | | (constexpr since C++26) | | ---------------------------------- | | ----------------------- |

Performs atomic notifying operations.

Unblocks all threads blocked in atomic waiting operations (i.e. wait()) on *_[ptr](../atomic%5Fref.html#ptr "cpp/atomic/atomic ref")_, if there are any; otherwise does nothing. This overload participates in overload resolution only if std::is_const_v<T> is false.

[edit] Notes

This form of change-detection is often more efficient than simple polling or pure spinlocks.

[edit] Example

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 3508(P3323R1) C++20 notify_all was meaningless for const T constrained to accept only non-const T

[edit] See also