Startup Sequence

1. Initialization

   Application initializes the async::internal::Task task objects, the bare minimum are:

   • The idle task

   • The timer task

required by FreeRTOS. However, typically more tasks will be needed in the application, e.g. communication (CAN, UDS, Ethernet), monitoring, SWC scheduler, as well as lifecycle task managing desired order of modules start up and shut down.

2. Running the Adapter

Before performing a first call to one of the async functions the application needs to start the FreeRTOS adapter by calling async::FreeRtosAdapter::run(). All required tasks are created and started by this call. The adapter will then start the FreeRTOS scheduler. As soon as the scheduler is running the adapter performs a call to the application-defined startApp function that was handed over on the call to async::FreeRtosAdapter::run().

The runnables are executed according to their priority and designated time, whether immediate or scheduled. Refer to Asynchronous execution for more information about task priorities.

If runnables are being executed or waiting for execution (scheduled runnables), the application can use the idle task to perform low-priority routines, such as monitoring console input/output.

Related types

• async::FreeRtosAdapter

• async::TaskInitializer

• async::StaticRunnable

Examples

Typical routine for creating, initializing, and starting a task:

using AsyncAdapter = ::async::AsyncBinding::AdapterType;

// assume the enumerator is defining the available tasks of RTOS:
enum
{
    TASK_BSP,
    TASK_UDS,
    TASK_DEMO
};

// make decision about the stack size for the task:
const uint32_t STACK_SIZE = 1024;

AsyncAdapter::Task<AsyncAdapter, TASK_DEMO, STACK_SIZE> demoTask{"demo"};

void startApp()
{
    // application-defined callback that performs first calls to async functions
}

...

AsyncAdapter::run(AsyncAdapter::StartAppFunctionType::create<&startApp>());