Component Time Sync Client Requirements#

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

Functional Requirements#

Shared Memory Channel Management
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client component shall provide operations to create, open, and close shared memory channels for gPTP data exchange between time daemon and time-aware applications.

Shared Memory Region Validation
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client component shall validate shared memory region integrity on Open operations and reject regions that fail validation.

Publisher Creates Channels
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client Publisher shall create shared memory channels that Receivers subsequently open.

Receiver Multi-Reader Semantics
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client Receiver shall support multiple concurrent readers accessing shared memory channels in read-only mode.

Data Validity Indication
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client Receiver shall indicate whether received data is valid or corrupted.

Lock-Free Synchronization
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Functional
version: 1

The ts_client component shall implement lock-free synchronization between writer and readers to prevent blocking and ensure readers can detect concurrent writes.

gPTP Synchronization Status Exchange
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Interface
version: 1

The ts_client component shall exchange gPTP synchronization status information containing synchronized state, timeout condition, time discontinuity detection (future and past), and correctness indication.

Sync/FollowUp Message Metadata Exchange
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Interface
version: 1

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.

PDelay Message Metadata Exchange
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Interface
version: 1

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, and request clock identity.

Time Correlation Data Exchange
status: valid
security: NO
safety: ASIL_B
tags: time, ts_client
reqtype: Interface
version: 1

The ts_client component shall exchange time correlation data containing synchronized PTP assumed time, local system time reference, and clock rate deviation.

Non-Functional Requirements#

Cache-Optimized Memory Layout
status: valid
security: NO
safety: ASIL_B
tags: ts_client
reqtype: Non-Functional
version: 1

The ts_client component shall optimize shared memory layout to prevent cache contention between concurrent writer and reader processes.

Assumption of Use Requirements#

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.