struct ara::diag::GenericDataIdentifier::OperationOutput

The data structure ara::diag::GenericDataIdentifier::OperationOutput encapsulates payload for positive response messages in the context of generic DID diagnostic operations ([SWS_DM_00641]). Upon an incoming diagnostic request, the application instantiates the structure and populates member responseData with the determined output data before passing it to Diagnostic Management ([SWS_DM_00631]). In doing so, the essential constraint applies that responseData must contain exclusively the pure payload and under no circumstances the actual Data Identifier. After transfer into the UDS response message, the lifecycle of the short-lived value object ends.

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Context

The data structure ara::diag::GenericDataIdentifier::OperationOutput is part of the diag module in the AUTOSAR Adaptive Platform and is provided via header ara/diag/generic_data_identifier.h ([SWS_DM_00641], [SWS_DM_00631]). Within the diagnostic architecture, the structure acts as a specialized data container for the result data of a positive diagnostic response message regarding a generic data identifier (DID) (AUTOSAR_AP_SWS_Diagnostics §8.19.2 “Struct: OperationOutput”).

In the interaction of the participating architectural components, OperationOutput forms the link between the application-specific diagnostic service function and the central Diagnostic Management. While the application is responsible for reading and preparing payload, the diagnostic runtime system handles higher-level protocol processing toward the external diagnostic tester. To pass the response data, the structure declares the public member variable responseData of type ara::core::Vector<std::uint8_t> ([SWS_DM_00631], AUTOSAR_AP_SWS_Diagnostics §8.19.2.1.1 “responseData”). This byte vector transports the payload of the positive response message, whereby the data identifier itself must not be contained in the vector ([SWS_DM_00631]).

Lifecycle

As a lightweight data transfer struct without its own methods, ara::diag::GenericDataIdentifier::OperationOutput is subject to a simple, transient value lifecycle ([SWS_DM_00641]). Instantiation occurs on demand within the application-specific handler routine as soon as a corresponding read or query operation for a generic DID has been processed successfully. The contained vector responseData is populated with the requested diagnostic payload ([SWS_DM_00631]).

Ownership is strictly sequential: The creating application initially holds the instance locally and passes it to the diagnostic framework upon completion. The lifetime of the instance ends as soon as Diagnostic Management has incorporated payload into the outgoing diagnostic response message. The handover back to the runtime system presumably takes place in a resource-efficient manner via move semantics or packaged in an asynchronous container such as ara::core::Future or ara::core::Result. Question Q-6e8dadb21e01d4fb (open) The structure does not provide internal synchronization for concurrent access; however, because it is populated and passed transiently within the executing worker thread of the operation, interpretation: cross-thread protection is not required in regular operation.

Usage Path

The typical invocation sequence during the processing of a generic diagnostic data query is divided into the following steps:

1. An external diagnostic tester initiates a query (for example, a UDS service for reading by data identifier) that is received by the Diagnostic Management of the vehicle.
2. The diagnostic system delegates the read request to the responsible instance of ara::diag::GenericDataIdentifier of the application.
3. The application determines the requested sensor data or internal parameters and instantiates ara::diag::GenericDataIdentifier::OperationOutput ([SWS_DM_00641]).
4. The application assigns the determined bytes to vector responseData ([SWS_DM_00631]). In doing so, the DID value itself must not be stored in responseData (AUTOSAR_AP_SWS_Diagnostics §8.19.2.1.1 “responseData”).
5. The populated instance is returned to Diagnostic Management, which prepends the DID, assembles the complete positive response message, and transmits it to the diagnostic tester.

Sequence diagram: Processing sequence of a generic data query using OperationOutput. Sources: [SWS_DM_00641], [SWS_DM_00631], AUTOSAR_AP_SWS_Diagnostics §8.19.2 “Struct: OperationOutput”.