Captures detailed timestamps and measurement values of a peer delay initiator for validating network latencies.
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translated from the German guidegemini-3.8-flash-low · 2026-10-13 · German original
Captures detailed timestamps and measurement values of a peer delay initiator for validating network latencies.
The structure ara::tsync::PdelayInitiatorMeasurementType stores detailed timestamps and measurement values recorded by a peer delay initiator during message exchange for time validation. It combines local transmission and reception timestamps with the values transmitted by the responder and records the calculated latency pDelay[SWS_TS_14166]. For unique assignment, the sequence number sequenceId[SWS_TS_14167] is maintained, while a reference tuple of local and global time secures the correlation. As a passive data container, the structure requires external synchronization during concurrent accesses.
Context
The data structure ara::tsync::PdelayInitiatorMeasurementType is part of the module tsync in the AUTOSAR Adaptive Platform and is provided via the header file ara/tsync/time_validation_measurement_types.h. Its primary responsibility is to encapsulate detailed timestamps and measurement values that arise on the part of the peer delay initiator (pDelay initiator) during propagation delay determination and time validation. As part of protocol execution, the initiator interacts across the network with a communication partner (responder) that receives and answers the peer delay requests. The acquired data makes it possible to precisely trace signal propagation delays between network nodes and analyze deviations between time bases. Typically, instances of this structure are passed to higher-level monitoring and validation entities after completion of a measurement cycle, so that the structure functions as an interface record between network protocol and diagnostic evaluation.
Lifecycle
The structure is declared as struct PdelayInitiatorMeasurementType final and serves as a pure data container without polymorphic properties or dynamic memory management. Instances typically originate on the stack or in the memory area of the synchronization subsystem at the beginning of or during a measurement process. During message exchange, the individual attributes are populated step by step with timestamps and protocol data. After completion of calculations, the consolidated object is passed by value or reference to consuming functions. Because no resources are allocated, the lifetime automatically ends upon leaving the enclosing scope. For concurrent usage, it must be taken into account that simultaneous write accesses to the same instance are not thread-safe; acquisition and consolidation of values take place sequentially in the execution context of the initiator before release for read-only further processing.
Usage Path
The typical usage path comprises the phase-appropriate recording of protocol timestamps and identifiers over the course of a complete peer delay measurement cycle:
When sending the request message Pdelay_Req, the initiator registers the message identifier in field sequenceId[SWS_TS_14167] and stores the local transmission time in Virtual Local Time as requestOriginTimestamp[SWS_TS_14160].
When the initiator receives the response Pdelay_Resp, it records the ingress time in Virtual Local Time in field responseReceiptTimestamp[SWS_TS_14161] and extracts the request arrival time in Global Time, recorded by the responder, from the response packet in order to store it in requestReceiptTimestamp[SWS_TS_14162].
Upon arrival of the follow-up message Pdelay_Resp_Follow_Up, the transmission time of the response in Global Time is extracted and stored in responseOriginTimestamp[SWS_TS_14163].
Once all time values are available, the initiator calculates the current delay pDelay[SWS_TS_14166]. For correlation between local and global time bases, the reference tuple consisting of referenceLocalTimestamp[SWS_TS_14164] (in Virtual Local Time) and referenceGlobalTimestamp[SWS_TS_14165] (in Global Time) is deposited in the measurement record.
The following sequence diagram illustrates the flow of message exchange and the step-by-step population of the measurement data structure:
After complete initialization of all fields, the data record is available for evaluations, plausibility checks, or logging to verify the integrity of the network synchronization.
This guide is based on the AUTOSAR Adaptive R25-11 specification (module tsync) and describes the structure PdelayInitiatorMeasurementType.
gemini-3.8-flash-low· 2026-10-13 · German original