RTOS/MSP432P401R: Do global variables shared between tasks (or clock functions) need to be marked as volatile?

Julian,

RTOS does not automatically make global variables volatile. If you wish to have global variables, it's suggested to mark them as volatile. I personally enjoy this description of the volatile keyword use's in embedded programming: https://barrgroup.com/Embedded-Systems/How-To/C-Volatile-Keyword

I would also suggest that if you do share a global variable between tasks, that you make sure the tasks do not try and utilize it at the same time. With regards to sharing information between tasks/threads/hwi/swis/etc, it may be useful to look into how to utilize Semaphore's, Gates, Mailboxes and Message Queue's. Check out the RTOS Concepts and TI-RTOS Basics SimpleLink Academy Labs as well as the TI-RTOS Kernal User's Guide for more information, specifically chapter 4.