THE GRAIL RING STRUCTURE AND PRIMITIVES

The paper gives a description of the ring-structure mechanism that controls the disposition of data and storage space in the GRAIL system. The ring structures--continuous chains of elements containing codes and either links or data--represent the logic of both the users program and of the system itself. The basic types are 1 system structure 2 files description structure 3 file structure 4 context structure and 5 plane structure. Common to the first three types is a space allocation substructure that describes the location of data sets within a particular area in secondary storage and of space available for use. Basic operations on ring structures--such as finding, procuring, and releasing elements--are performed by ring structure primitives, written as a group of remote code sequences.