Component Time Sync Client Requirements#

Time Sync Client Requirements		status: draft security: NO safety: ASIL_B
tags: requirements, ts_client, ts_client version: 1 realizes: wp__requirements_comp

doc__ts_client_requirements		Generic Document

Functional Requirements#

Shared Memory Channel Management		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_ctrl_flow, feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall provide operations to create, open, and close shared memory channels for gPTP data exchange between time_slave and time_daemon.
comp_req__ts_client__shared_memory_mgmt		Component Requirement

Shared Memory Region Validation		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_acc_qual_api, feat_req__time__vehicle_time_sync, feat_req__time__vehicle_time_time_pt_qual satisfied by: comp__ts_client
The ts_client component shall validate shared memory region integrity on Open operations and reject regions that fail validation.
comp_req__ts_client__shm_validation		Component Requirement

Publisher Creates Channels		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client Publisher shall create shared memory channels that Receivers subsequently open.
comp_req__ts_client__publisher_creates		Component Requirement

Receiver Multi-Reader Semantics		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_ctrl_flow satisfied by: comp__ts_client
The ts_client Receiver shall support multiple concurrent readers accessing shared memory channels in read-only mode.
comp_req__ts_client__receiver_multi_reader		Component Requirement

Data Validity Indication		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_acc_qual_api, feat_req__time__vehicle_time_sync, feat_req__time__vehicle_time_time_pt_qual satisfied by: comp__ts_client
The ts_client Receiver shall indicate whether the shared memory channel is obviously corrupted.
comp_req__ts_client__data_validity		Component Requirement

Lock-Free Synchronization		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_ctrl_flow, feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall implement non-blocking synchronization between writer and readers and ensure readers can detect concurrent writes.
comp_req__ts_client__seqlock_protocol		Component Requirement

gPTP Synchronization Status Exchange		status: valid security: NO safety: QM
tags: ts_client reqtype: Interface version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall exchange gPTP synchronization status information containing synchronized state and timeout condition.
comp_req__ts_client__sync_status_data		Component Requirement

Sync/FollowUp Message Metadata Exchange		status: valid security: NO safety: QM
tags: ts_client reqtype: Interface version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall exchange gPTP Sync and FollowUp message metadata containing precise origin timestamp, reference global timestamp, reference local timestamp, sync ingress timestamp, correction field, sequence identifier, path delay, port number, and clock identity.
comp_req__ts_client__sync_fup_data		Component Requirement

PDelay Message Metadata Exchange		status: valid security: NO safety: QM
tags: ts_client reqtype: Interface version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall exchange gPTP Peer Delay (PDelay) message metadata containing request origin timestamp, request receipt timestamp, response origin timestamp, response receipt timestamp, path delay measurement, request port number, response port number, request clock identity, response clock identity, reference global timestamp, and reference local timestamp.
comp_req__ts_client__pdelay_data		Component Requirement

Time Correlation Data Exchange		status: valid security: NO safety: QM
tags: ts_client reqtype: Interface version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall exchange time correlation data containing synchronized PTP assumed time, local system time reference, and clock rate deviation.
comp_req__ts_client__time_correlation_data		Component Requirement

Platform Support		status: valid security: NO safety: QM
tags: ts_client reqtype: Functional version: 1 derived from: feat_req__time__vehicle_time_sync satisfied by: comp__ts_client
The ts_client component shall support POSIX and QNX 8.0 SDP platforms for shared memory operations and inter-process communication.
comp_req__ts_client__platform_support		Component Requirement

Cache-Optimized Memory Layout		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Non-Functional version: 1 derived from: feat_req__time__vehicle_time_ctrl_flow satisfied by: comp__ts_client
The ts_client component shall optimize shared memory layout to prevent cache contention between concurrent writer and reader processes.
comp_req__ts_client__cache_optimization		Component Requirement

Single Publisher Process		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Process version: 1
The ts_client user shall ensure that only one publisher process opens and writes to a shared memory segment to maintain data consistency. Multiple publishers writing to the same segment will cause data corruption and readers will receive invalid data.
aou_req__ts_client__single_publisher		Assumption of Use Requirement

Shared Memory Permissions		status: valid security: NO safety: ASIL_B
tags: ts_client reqtype: Process version: 1
The user shall configure system permissions to allow publisher write access and readers read access to shared memory segments. Incorrect permissions will cause channel creation or opening failures.
aou_req__ts_client__shm_permissions		Assumption of Use Requirement