design-docs/real-time-thread-priorities.md

# Real-time thread priorities

|Name               |Location                                                                                     |Priority|
|-------------------|---------------------------------------------------------------------------------------------|--------|
|CAN HAL thread     |[hal/src/main/native/systemcore/CAN.cpp](../hal/src/main/native/systemcore/CAN.cpp)          |50      |
|Notifier HAL thread|[hal/src/main/native/systemcore/Notifier.cpp](../hal/src/main/native/systemcore/Notifier.cpp)|40      |
[hal] Refactor threads API (#8701) Since sched_setscheduler() requires non-RT priorities to be 0, we can use that as a sentinel value for disabling RT and condense the Java API to just two functions with fewer parameters. The thread priority setter is deprecated since only experts should use it. The HAL Notifier thread priority setter was replaced with setting the priority in the thread itself. The C++ Notifier non-RT and RT constructors were deduplicated. The real-time scheduler was changed from SCHED_FIFO to SCHED_RR, which is SCHED_FIFO with threads allowed to run for a maximum time quantum before yielding (100 ms by default). 2026-04-06 08:49:43 -07:00			`# Real-time thread priorities`

			`\|Name \|Location \|Priority\|`
			`\|-------------------\|---------------------------------------------------------------------------------------------\|--------\|`
			`\|CAN HAL thread \|[hal/src/main/native/systemcore/CAN.cpp](../hal/src/main/native/systemcore/CAN.cpp) \|50 \|`
			`\|Notifier HAL thread\|[hal/src/main/native/systemcore/Notifier.cpp](../hal/src/main/native/systemcore/Notifier.cpp)\|40 \|`