适用于开发完整应用的模版

An application can be written to run as either a task (a module with its own stack and process priority) or as a work queue task (a module that runs on a work queue thread, sharing the stack and thread priority with other tasks on the work queue). 在大多数情况下，可以使用工作队列任务，因为这会减少资源的使用。

INFO

Architectural Overview > Runtime Environment provides more information about tasks and work queue tasks.

INFO

All the things learned in the First Application Tutorial are relevant for writing a full application.

工作队列任务

PX4-Autopilot contains a template for writing a new application (module) that runs as a work queue task: src/examples/work_item.

工作队列任务应用程序与普通(任务)应用程序相同。 除了它需要指定它是一个工作队列任务，并在初始化期间运行调度它本身。

示例显示了如何操作。 总结：

1. Specify the dependency on the work queue library in the cmake definition file (CMakeLists.txt):

   ...
   DEPENDS
      px4_work_queue

2. In addition to ModuleBase, the task should also derive from ScheduledWorkItem (included from ScheduledWorkItem.hpp)

3. 在构造函数初始化中指定要添加任务的队列。 The work_item example adds itself to the wq_configurations::test1 work queue as shown below:

   WorkItemExample::WorkItemExample() :
       ModuleParams(nullptr),
       ScheduledWorkItem(MODULE_NAME, px4::wq_configurations::test1)
   {
   }

   INFO

   The available work queues (wq_configurations) are listed in WorkQueueManager.hpp.

:::

4. Implement the ScheduledWorkItem::Run() method to perform "work".

5. Implement the task_spawn method, specifying that the task is a work queue (using the task_id_is_work_queue id.

6. Schedule the work queue task using one of the scheduling methods (in the example we use ScheduleOnInterval from within the init method).

任务

PX4/PX4-Autopilot contains a template for writing a new application (module) that runs as a task on its own stack: src/templates/template_module.

该模板演示了完整应用程序所需或有用的以下附加功能/方面：

• 访问参数并对参数更新做出反应。
• 订阅、等待 topic 更新。
• Controlling the task that runs in the background via start/stop/status. The module start [<arguments>] command can then be directly added to the startup script.
• 命令行参数解析。
• Documentation: the PRINT_MODULE_* methods serve two purposes (the API is documented in the source code):
  • They are used to print the command-line usage when entering module help on the console.
  • They are automatically extracted via script to generate the Modules & Commands Reference page.