RTEMS 4.7.1 On-Line Library

Task Manager Task States

RTEMS Ada User's Guide

5.2.3: Task States

A task may exist in one of the following five states:

executing - Currently scheduled to the CPU
ready - May be scheduled to the CPU
blocked - Unable to be scheduled to the CPU
dormant - Created task that is not started
non-existent - Uncreated or deleted task

An active task may occupy the executing, ready, blocked or dormant state, otherwise the task is considered non-existent. One or more tasks may be active in the system simultaneously. Multiple tasks communicate, synchronize, and compete for system resources with each other via system calls. The multiple tasks appear to execute in parallel, but actually each is dispatched to the CPU for periods of time determined by the RTEMS scheduling algorithm. The scheduling of a task is based on its current state and priority.

RTEMS Ada User's Guide