# Section 8.13:
Operating System Classes

This section of the required library contains definitions of those abstractions which describe the required interface between the reuired library and an execution environment operating system. No implementation classes are defined.

1. Abstract Classes

   1. $EXTERNAL_REF - this abstraction should be inherited by any class which provides operating system reference values.
   2. $OPERATING_SYS - this specifies the operating system services in communicating with the execution environment.
   3. $OPSYS_TIME - this is the interface to the operating system real time of day clock.
   4. $OPSYS_TIME_USAGE - this specifies those statistics which an operating system is to provide for use in evaluating program run time clock values.
   5. $OPSYS_TIMERS - this specifies the clocks/timers which should be available to the required library.
   6. $OPSYS_TIMER - a high resolution clock timer.
   7. $OPSYS_FILE_LABEL - this class indicates the minimum list of file label components used by the required library.
   8. $OPSYS_FILE_SYS - this class provides the specification of all file/directory services.

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Comments or enquiries should be made to Keith Hopper. Page last modified: Friday, 10 March 2000. |