|   | 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.
  - Abstract Classes - 
      - $EXTERNAL_REF - this abstraction
        should be inherited by any class which provides operating system
        reference values.
- $OPERATING_SYS - this specifies
        the operating system services in communicating with the execution
        environment.
- $OPSYS_TIME - this is the interface
        to the operating system real time of day clock.
- $OPSYS_TIME_USAGE - this
        specifies those statistics which an operating system is to provide for
        use in evaluating program run time clock values.
- $OPSYS_TIMERS - this specifies the
        clocks/timers which should be available to the required library.
- $OPSYS_TIMER - a high resolution
        clock timer.
- $OPSYS_FILE_LABEL - this class
        indicates the minimum list of file label components used by the
        required library.
- $OPSYS_FILE_SYS - this class
        provides the specification of all file/directory services.
 
 
  
    
      | Comments
        or enquiries should be made to Keith Hopper. Page last modified:  Friday, 10 March 2000.
 |   |