class ara::shwa::Device

Serves to abstract and manage hardware accelerators within the Adaptive Platform AUTOSAR_AP_SWS_SafeHardwareAcceleration p. 12. Instances are created exclusively via factory methods such as Create() and offer operations for checking the device type as well as reading specific characteristics [AP_SWS_SHWA_00308], [AP_SWS_SHWA_00313]. Because the operations are not thread-safe, usage in multi-threaded environments requires external synchronization.

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Context

The class ara::shwa::Device serves in the Safe Hardware Acceleration module as the primary abstraction for physical compute units AUTOSAR_AP_SWS_SafeHardwareAcceleration p. 12. Within the Adaptive Platform, it enables Adaptive Applications as well as other functional clusters to access and manage accelerator resources. A typical overall system combines instances of Device with execution queues and memory buffers to delegate compute-intensive tasks to accelerator hardware in a structured manner SWS_SafeHardwareAcceleration p. 22.

Context diagram: Integration of ara::shwa::Device in interaction with application, queues, and hardware. Sources: AUTOSAR_AP_SWS_SafeHardwareAcceleration p. 12, SWS_SafeHardwareAcceleration p. 22

Lifecycle

The creation of ara::shwa::Device objects is strictly controlled: the default constructor is explicitly deleted [AP_SWS_SHWA_00302]. Instances can be created exclusively via the static factory methods Create(), either without parameters for a default device [AP_SWS_SHWA_00308] or parameterized via a selector object by means of Create(const DeviceSelector&) [AP_SWS_SHWA_00309]. Both methods return a ara::core::Result<Device>.

Regarding resource ownership, the class possesses regular copy and move semantics: both copy constructor [AP_SWS_SHWA_00303] and copy assignment operator [AP_SWS_SHWA_00304] as well as move constructor [AP_SWS_SHWA_00305] and move assignment operator [AP_SWS_SHWA_00306] are declared as noexcept=default. Interpretation: Internally, the object is likely designed as a lightweight handle to the actual hardware resource, so that copies are possible without overhead and in an exception-safe manner. Question Q-a6ff4d89f19b0f36 (open) The lifetime of the physical hardware interface is tied to the runtime of the underlying driver or subsystem, while the instance can be passed along at the application level like a regular value type. All factory calls and methods of the class are specified as not thread-safe.

Usage Path

A typical usage path begins with instantiation via one of the factory methods. Following a successful return, the instance is inspected to determine the type of compute unit and query device-specific parameters. Subsequently, the device is typically assigned to queues and buffers to execute processing tasks.

1. Instantiation: Calling Create() or Create(deviceSelector) to provide the device [AP_SWS_SHWA_00308], [AP_SWS_SHWA_00309].
2. Type check: Validation of the hardware category via the predicates IsCpu() [AP_SWS_SHWA_00310], IsGpu() [AP_SWS_SHWA_00311], or IsAccelerator() [AP_SWS_SHWA_00312].
3. Configuration query: Reading detailed device information via the template method GetInfo<InfoType>() [AP_SWS_SHWA_00313].

Sequence diagram: Typical sequence of initialization, type checking, and information querying. Sources: [AP_SWS_SHWA_00309], [AP_SWS_SHWA_00311], [AP_SWS_SHWA_00313]

Error Scenarios

Methods of ara::shwa::Device communicate error states deterministically via the error type ara::core::Result. The following error cases are specified:

• ShwaErrorCode::kResourceBusy: Occurs when a resource is busy at the time of the request. This can be triggered both during instance creation [AP_SWS_SHWA_00308], [AP_SWS_SHWA_00309] and during check operations such as IsCpu() [AP_SWS_SHWA_00310], IsGpu() [AP_SWS_SHWA_00311], or IsAccelerator() [AP_SWS_SHWA_00312].
• ShwaErrorCode::kFeatureNotSupported: Reported when a requested property or device configuration is not supported by the system. This affects the creation methods [AP_SWS_SHWA_00308], [AP_SWS_SHWA_00309] as well as querying feature structures via GetInfo<InfoType>() [AP_SWS_SHWA_00313].

With regard to exception safety, all operations are considered exception safe or are annotated with noexcept. Because the operations are not thread-safe, concurrent calls on the same instance or shared hardware resources must be synchronized by the application layer.