class ara::nm::NmException

The exception class serves as a standardized error type for synchronous runtime and API errors within the Network Management functional cluster according to [SWS_ANM_01100]. Instances encapsulate the underlying error cause and are created by passing a specific error code [SWS_ANM_01102]. By specializing the general base exception, the type enables targeted exception handling for failing Network Management operations. As an essential constraint, the constructor guarantees full thread safety and compliance with the not-throw guarantee during object creation.

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Context

Within the Network Management functional cluster (ara::nm), class ara::nm::NmException acts as the central exception type for signaling errors at the API level [SWS_ANM_01100]. It is declared in header file ara/nm/nm_error_domain.h and publicly derives from the general base class ara::core::Exception [SWS_ANM_01100]. In the architecture of the AUTOSAR Adaptive Platform, it thus bridges the module-specific error states of Network Management and the standardized C++ exception handling mechanism of the base infrastructure.

Interaction partners include the Network Management API interfaces as well as application-specific components that utilize services of this cluster. If a severe or synchronously handleable error condition occurs during the execution of such an interface, the exception object encapsulates this error for propagation to higher-level callers [SWS_ANM_01100]. Through the inheritance hierarchy, NmException integrates seamlessly into general exception handling routines and can be caught both module-specifically and polymorphically via references to ara::core::Exception.

Lifecycle

The lifecycle of an instance of ara::nm::NmException begins with its explicit instantiation via the constructor, to which an error code of type ara::core::ErrorCode is passed [SWS_ANM_01102]. By marking the constructor with the keyword explicit, the specification prevents implicit type conversions from error codes, thereby enforcing deliberate and type-correct object creation [SWS_ANM_01102].

Regarding concurrency, the construction of the exception is specified as thread-safe (thread-safe) [SWS_ANM_01102]. Instantiation can therefore safely take place concurrently on different threads without calling components having to establish external synchronization mechanisms. In addition, the constructor is declared with noexcept [SWS_ANM_01102], which formally guarantees that no further exceptions can be thrown during object creation itself.

After creation, the instance is transported to the responsible exception handler via the C++ stack mechanism. Destruction occurs automatically upon leaving the associated catch block in accordance with standard C++ programming language rules for exception objects.

Usage Path

The regular usage path comprises the occurrence of an error during interaction with the Network Management API, the creation of the exception object, and its subsequent evaluation by the application. Presumably, the exception is triggered primarily when synchronous calls fail or errors from return values are explicitly unpacked as an exception. Question Q-636ec24993a10a5b (open)

Sequence diagram: Typical flow of error handling via an exception during calls to the Network Management API. Sources: [SWS_ANM_01100], [SWS_ANM_01102]

The typical flow is divided into the following steps:

• Call to the API operation: The application calls a Network Management function.
• Error detection and construction: If the API implementation detects an error condition, it creates an instance of NmException by passing the specific error code [SWS_ANM_01102].
• Throwing the exception: The exception is raised (throw), interrupting the normal control flow [SWS_ANM_01100].
• Catching and error handling: The application catches the exception by reference as const ara::nm::NmException& and initiates appropriate recovery or logging actions.

Error Scenarios

As an exception class, ara::nm::NmException represents the tool for error representation and is not itself subject to complex error scenarios during operation [SWS_ANM_01100]. The essential precondition for creation consists in providing an initialized ara::core::ErrorCode object [SWS_ANM_01102]. This error code is likely to represent the error domain and the numeric identifier of the specific NM issue. Question (open)

Since the constructor is declared as noexcept, failure during creation of the exception object is ruled out [SWS_ANM_01102]. The primary error scenario at the system level is the failure to implement appropriate exception handling: If a thrown NmException remains uncaught, this results in a call to std::terminate and thus in the uncontrolled termination of the process. Applications must therefore ensure that calling code sections are protected with corresponding handling blocks.