Thread Model (FA Model)

There are three types of threads in the FA model:

• Main thread

  Manages other threads.

• Ability thread

  • One ability thread for each ability.
  • Distributes input events.
  • Draws the UI.
  • Invokes application code callbacks (event processing and lifecycle callbacks).
  • Receives messages sent by the worker thread.

• Worker thread

  Performs time-consuming operations

Based on the OpenHarmony thread model, different services run on different threads. Service interaction requires inter-thread communication. Threads can communicate with each other in Emitter or Worker mode. Emitter is mainly used for event synchronization between threads, and Worker is mainly used to execute time-consuming tasks.

NOTE

The FA model provides an independent thread for each ability. Emitter is mainly used for event synchronization within the ability thread, between a pair of ability threads, or between the ability thread and worker thread.