Module kernel::sync::atomic::ordering

Memory orderings.

The semantics of these orderings follows the LKMM definitions and rules.

• Acquire provides ordering between the load part of the annotated operation and all the following memory accesses, and if there is a store part, the store part has the Relaxed ordering.
• Release provides ordering between all the preceding memory accesses and the store part of the annotated operation, and if there is a load part, the load part has the Relaxed ordering.
• Full means “fully-ordered”, that is:
  • It provides ordering between all the preceding memory accesses and the annotated operation.
  • It provides ordering between the annotated operation and all the following memory accesses.
  • It provides ordering between all the preceding memory accesses and all the following memory accesses.
  • All the orderings are the same strength as a full memory barrier (i.e. smp_mb()).
• Relaxed provides no ordering except the dependency orderings. Dependency orderings are described in “DEPENDENCY RELATIONS” in LKMM’s explanation.

Structs

• Acquire
  The annotation type for acquire memory ordering, for the description of acquire memory ordering, see module-level documentation.
• Full
  The annotation type for fully-ordered memory ordering, for the description fully-ordered memory ordering, see module-level documentation.
• Relaxed
  The annotation type for relaxed memory ordering, for the description of relaxed memory ordering, see module-level documentation.
• Release
  The annotation type for release memory ordering, for the description of release memory ordering, see module-level documentation.

Traits

• AcquireOrRelaxed
  The trait bound for operations that only support acquire or relaxed ordering.
• Ordering
  The trait bound for annotating operations that support any ordering.
• ReleaseOrRelaxed
  The trait bound for operations that only support release or relaxed ordering.