| name | 0.6.5-understand-rmw_ind_003 |
| description | [0.6.5] modify_phase: the purely computational step wherein the value captured in the read phase is transformed by the |
understand-rmw_ind_003
CALL NUMBER: deep_indivisibility_prope.rmw_ind_003 : deep_c11_memory_model(3)
DEFINITION: modify_phase: the purely computational step wherein the value captured in the read phase is transformed by the operation's specific function (addition, subtraction, bitwise OR, bitwise AND, exclusive OR, maximum, minimum, or conditional replacement); this phase produces the value to be written but does not interact with memory.
Invoke this skill to understand rmw_ind_003 down to its primitives. The RELATIVE ROOT below is the least-fixed-point closure of everything it bundles from — the full import cone, grouped by the lib each prim comes from. Projected from a prover-typed KB (MAP/SWI-Prolog consistency gate): every reference below resolves.
THE RELATIVE ROOT (the import cone, by lib)
from deep_c11_memory_model
- load_indivisibility (d3): A relaxed atomic load returns exactly one value from the modification order of the target variable; no torn read of a partial value encoded in fewer bits than the atomic word is possible.
- store_indivisibility (d3): A relaxed atomic store writes the complete value as one indivisible step; no intermediate write of a partial value encoded in fewer bits than the atomic word is observable by any thread.
- no_tearing_guarantee (d4): The guarantee that multi-byte atomic values cannot be observed in a torn state where some bytes reflect the old value and others reflect a new concurrent value.
from deep_indivisibility_prope
- rmw_ind_004 (d1): write_phase: the final step wherein the result of the modify phase is written atomically to the target variable; this write becomes the new current value visible in the modification order for all subsequent operations.
- rmw_ind_006 (d2): modification_order_commitment: the serialization of the RMW operation into the global modification order of the target atomic variable at the instant the write_phase becomes visible; this ordering point determines the value returned by concurrent operations.
CONSUMERS (what needs this)
rmw_ind_001, rmw_ind_002
Projected from the concurrency synchronization primitives and memory models KB (407 concepts / 477 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.
(leaf — this is an actual skill.)
