Persistency Assumptions of Use

Persistency Feature AoU		status: valid security: NO safety: ASIL_B
tags: persistency version: 1 realizes: wp__requirements_feat_aou
doc__persistency_feat_aou		Generic Document

Assumptions of use of the feature, resulting from Persistency FMEA (doc__persistency_fmea) and Persistency DFA (doc__persistency_dfa).

AoU

Persistency Error handling		status: valid security: NO safety: ASIL_B
tags: persistency, environment reqtype: Functional version: 2 mitigates: feat_saf_dfa__persistency__data_corruption, feat_saf_dfa__persistency__execution_blocking, feat_saf_fmea__persistency__constraint_max, feat_saf_fmea__persistency__corrupt_load, feat_saf_fmea__persistency__corrupt_store, feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
The user shall detect and handle the unavailability of the feature persistency. Unavailability covers errors reported by the persistency API.
aou_req__persistency__error_handling		Assumption of Use Requirement

Separate KVS Instances per Software Element		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Process version: 1 mitigates: feat_saf_dfa__persistency__shared_instance
The user shall ensure that each FFI element (process) uses KVS storage, identified by directory and instance ID, which is not used by any other FFI element, so that persisted data of one FFI element cannot be read or modified by another FFI element. Note: The KVS does not synchronise access between processes. Processes which open the same directory and instance ID access the same files.
aou_req__persistency__instance_separation		Assumption of Use Requirement

Start without Persisted Data		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional version: 1 mitigates: comp_saf_fmea__kvs__empty_storage_used, feat_saf_fmea__persistency__corrupt_load
The user shall configure, for each KVS instance, whether existing persisted data is required when opening it, or handle that the KVS instance provides only default values because no persisted data is available.
aou_req__persistency__start_without_data		Assumption of Use Requirement

Flush of Safety Relevant Changes		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional version: 1 mitigates: comp_saf_fmea__kvs__unflushed_lost, feat_saf_fmea__persistency__corrupt_store
The user shall flush changes which shall be persisted and shall consider changes as persisted only after the flush has returned without error. If the flush reports an error, the user shall treat the changes as not persisted.
aou_req__persistency__flush		Assumption of Use Requirement