Still, the MPTSK layer only takes into account task's interaction with themselves, not with the outside world. The system will have no problems until two (or more) tasks want to use the same resource at the same time. A final layer, MPRES, is need to share resources.
The MPRES layer is best viewed as an open-ended extension of the MPTSK environment. Unfortunately, only basic resource management (regulated access) can be defined in a portable fashion (short of writing an entire operating system). Though all machines have processors and memory, they vary widely in their devices. Support for a default set of resource types is provided. For other, more esoteric devices, the layer shows how the user can build resource managers tailored to his environment.