List Processing in Xinu

List Processing in XINU

List processing in XINU is fairly straight-forward. We cover it here because lists are such a central part of any O/S and because understanding the XINU list implementation will enable you to read the XINU source code.

Introduction

In XINU, as in most O/Ss, processes are kept on lists. There is generally a separate list for each process state. There is only one list data structure (one type of list) in XINU. However, the same data structure is used for two types of lists:

FIFO lists
Priority Queues

One simplifying assumption (and guarantee) made by XINU is that a process will only appear on at most one list at a time. This reduces the complexity of the list data-structures and manipulation routines.