AoU: ETAS_RTACAR_SM_OS_019
**************************

The ETAS_RTACAR_SM_OS_019 AoU requires that there is a complete mapping between events and the tasks
that wait for them.

Every ``OsEvent`` defined in the OS ECUC configuration must be referenced by at
least one ``OsTask`` via an ``OsTaskEventRef`` entry.

An event that is defined but never waited upon is either dead configuration or a latent logic error —
a ``SetEvent`` call on such an event would silently have no effect, potentially hiding a synchronization
defect.

Events and the ``WaitEvent`` API are exclusively used by extended tasks. If the project does not use
extended tasks at all, no events are declared and no ``WaitEvent`` calls are made, so the AoU is
trivially satisfied.

Verification Approach
=====================

The verification is performed by analyzing the OS ECUC configuration files (ARXML) provided via the
``--os-arxml`` parameter or discovered in the project directory specified by ``--dir``.

The tool performs the following steps:

1. **Configuration Loading**: Parses the ARXML files to extract the OS configuration, including task
   definitions, event definitions, and event references.

2. **Extended Task Detection**: Identifies tasks configured as extended tasks (tasks that reference
   events via ``OsTaskEventRef``).

3. **Scalability Class Validation**: Checks that the ``OsScalabilityClass`` parameter is consistent
   across all configuration files. If incompatible values are detected, manual verification is required.

4. **Result Reporting**: Generates one of the following results based on the analysis outcome.


.. important:: Automated Verification Scope

   The current implementation **detects** the presence of extended tasks in the ECUC configuration but
   does **not yet implement full automated verification** of the event-to-task mapping specified in the AoU.

When extended tasks are detected, the tool reports a **review** result, requiring manual verification
to confirm compliance with the complete AoU requirement as stated in the :cite:t:`ETAS_SM`.


ARXML Configuration Requirements
================================

To enable this check, the OS ECUC configuration must be provided in AUTOSAR ARXML format. The tool
analyzes:

- **Task definitions** (``OsTask`` containers) to identify extended tasks
- **Event references** (``OsTaskEventRef``) to determine which tasks are extended
- **Scalability class settings** (``OsScalabilityClass``) to ensure configuration consistency


.. include:: ../rules/ETAS_RTACAR_SM_OS_019.rst

See Also
========

- :ref:`os_command_options` for information on providing ARXML files via ``--os-arxml`` or ``--dir``
- :cite:t:`ETAS_SM` section on event management and the WaitEvent/SetEvent API pair
- :cite:t:`AUTOSAR` specification for extended task scheduling and event ownership semantics