Introduction to the New Mainframe: Large-Scale Commercial Computing

Chapter 3. Scalability 53

z/OS services manipulate data within the structures. There are three types of

structure:

Cache structure Supplies a mechanism called

buffer invalidation to ensure

consistency of cached data. The cache structure can also be

used as a high-speed buffer for storing shared data with

common read/write access.

List structure Enables authorized applications to share data that is

organized in a set of lists, for implementing functions such as

shared work queues and shared status information.

Lock structure Supplies shared and exclusive locking capability for

serialization of shared resources down to a very small unit of

data.

The Coupling Facility can be used by any authorized program. Most operating

system components and subsystems ...