Rule 2 solutions

RTOS may intercept calls to interrupt routines and will not switch tasks until the interrupt completes. (So a write to a queue during an interrupt routine won't cause a task blocked on reading to execute until interrupt routine finishes.)
- Requires programmer intervention to inform RTOS where the interrupt routines are and which hardware interrupt corresponds with which routine.

RTOS may intercept calls to interrupt routines and will not switch tasks until the interrupt completes. (So a write to a queue during an interrupt routine won't cause a task blocked on reading to execute until interrupt routine finishes.)