However, endpoint values are in general larger numbers and depend on a "generation" value.

For a valid endpoint, the generation number is:

    generation = endpoint / M

    (same constant M)

    M is the generation "size"

    M = NR_TASKS + _MAX_MAGIC_PROC + 1

    NR_TASKS = 4
    _MAX_MAGIC_PROC = 0x8ace

    (See /usr/src/include/minix/endpoint.h )

When a process is forked, a generation value one greater than the parent's generation is used to compute the child's endpoint value together with the index value of a free slot in the process table.

The endpoint for a process can be set to an invalid endpoint value (E.g., NONE). For example, the kernel may need to prevent this process from receiving any more messages if it is terminating.