AtomicUpdateOrdering

Ordering Values

• static var relaxed: AtomicUpdateOrdering

  Guarantees the atomicity of the specific operation on which it is applied, but imposes no ordering constraints on any other variable accesses.

• static var acquiring: AtomicUpdateOrdering

  An acquiring update synchronizes with a releasing operation whose value its reads. It ensures that the releasing and acquiring threads agree that all subsequent variable accesses on the acquring thread happen after the atomic operation itself.

• static var releasing: AtomicUpdateOrdering

  A releasing update synchronizes with acquiring operations that read the value it stores. It ensures that the releasing and acquiring threads agree that all preceding variable accesses on the releasing thread happen before the atomic operation itself.

• static var acquiringAndReleasing: AtomicUpdateOrdering

  An acquiring-and-releasing operation is a combination of .acquiring and .releasing operation on the same variable.

• static var sequentiallyConsistent: AtomicUpdateOrdering

  A sequentially consistent update performs an acquiring-and-releasing update and also guarantees that it and all other sequentially consistent atomic operations (loads, stores, updates) appear to be executed in a single, total sequential ordering.