Do I need to protect adi_mbox_GetMessageBuffer?

Is it necessary to protect calls to adi_mbox_GetMessageBuffer with mutex/semaphore acquisition?

The Mbox_Example project surrounds that call w/ semaphore access. However it looks like the underlying Mbox_AllocBuffer/Mbox_Alloc_MultiBufferSlots calls may have their own exclusive access protections? Not sure.

Is the semaphore protection used in Mbox_example required?