Retentive state

Gap capability: state that survives process restarts — the equivalent of NVRAM-backed retentive memory in classical PLCs.

Feature: Retentive state FEAT_0020
status: open
satisfies: FEAT_0010
is satisfied by: REQ_0090, REQ_0091, REQ_0092, REQ_0093

State that survives process restarts — the equivalent of NVRAM-backed retentive memory in classical PLCs.

Requirement: Process-restart persistence REQ_0090
status: open
satisfies: FEAT_0020

The runtime shall provide a retentive memory abstraction whose declared contents persist unchanged across cooperative process restarts.

Requirement: Memory-mapped backing REQ_0091
status: open
satisfies: FEAT_0020

Retentive memory regions shall be backed by a memory-mapped file with a checksum verified at load.

Requirement: Crash-atomic checkpoints REQ_0092
status: open
satisfies: FEAT_0020

A retentive-memory checkpoint shall be atomic with respect to process crash — a concurrent crash shall yield either the pre-checkpoint or post-checkpoint contents, never a partial state.

Requirement: Recovery status reporting REQ_0093
status: open
satisfies: FEAT_0020

At startup, the runtime shall report whether retentive state was loaded cleanly, recovered from an incomplete checkpoint (and which version was selected), or initialised from defaults because no prior state existed.