OS Primitives: Overview
=======================

Interrupts
----------

.. topic:: See also

   * :doc:`../interrupt/index`

* Interrupt lines ("interrupts") referenced by numbers
* Interrupt service routines (ISR) associated with those numbers
* Called *asynchronously*

Spinlocks
---------

.. topic:: See also

   * :doc:`../spinlocks/index`

* Used to protect short critical sections
* On a multiprocessor, the locker spins until lock is free

Schedulable Context (Threads)
-----------------------------

.. topic:: Documentation

   * :doc:`../threads/index`

* Threads
* Context switches
* *Blocking*
* Realtime priorities
* Zephyr: cooperative (voluntary yield) or preemptive (timeslices)




Polling
-------

* ``k_poll_signal_raise()`` jjj





Optional
--------

Deadlock Scenarios
..................

* fifo, rr wiederholung jjj
* prio inher jjj
* prio inversion jjj

Random Stuff
............

* Terminlogy

  * isr, interrupt number
  * spinlock
  * mutex
  * scheduling, realtime
  * message queue
  * pipe
  * workqueue?
  * condition variables -> cannot be polled
  * poll

* mutex

  * **blocks**, as opposed to spinlock
  * recursive
  * lock in isr bad
  * prio inher -> wtf?