| 124,16 → 124,24 |
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| <formalpara> |
| <title>Thread states</title> |
| |
| <para>In each moment, a thread exists in one of five possible thread |
| <para>In each moment, a thread exists in one of six possible thread |
| states. When the thread is created and first readied into the |
| scheduler's run queues or when a thread is migrated to a new processor, |
| it is put into the <code>Entering</code> state. After some time, the |
| scheduler picks up the thread and starts executing it. A thread being |
| currently executed on a processor is in the <code>Running</code> state. |
| From there, the thread has three possibilities. It either runs until it |
| is preemtped, in which case the state changes to <code>Ready</code>, |
| goes to the <code>Sleeping</code> state by going to sleep or enters the |
| <code>Exiting</code> state when it reaches termination.<figure> |
| it is put into the <constant>Entering</constant> state. After some time, |
| the scheduler picks up the thread and starts executing it. A thread |
| being currently executed on a processor is in the |
| <constant>Running</constant> state. From there, the thread has three |
| possibilities. It either runs until it is preemtped, in which case the |
| state changes to <constant>Ready</constant>, goes to the |
| <constant>Sleeping</constant> state by going to sleep or enters the |
| <constant>Exiting</constant> state when it reaches termination. When the |
| thread exits, its kernel structure usually stays in memory, until the |
| thread is detached by another thread using <code>thread_detach</code> |
| function. Terminated but undetached threads are in the |
| <constant>Undead</constant> state. When the thread is detached or |
| detaches itself during its life, it is destroyed in the |
| <constant>Exiting</constant> state and the <constant>Undead</constant> |
| state is not reached.<figure> |
| <title>Transitions among thread states.</title> |
| |
| <mediaobject id="thread_states" xreflabel=""> |