Interrupt System: The interrupt is vital for the function of any OS, Its functions are:
To alert the O/S when an ‘event’ occur so that it can suspend its current activity and deal appropriately with the new situation.
To enable several programs and I/O activities to proceed independently and asynchronously while having overall control been retained by the O/S.
Interrupt may be generated by a number of resources such as;
By the I/O controller, signalling normal completion or occurrence of an error or failed condition
By an internal process clock; used to interrupt the O/S at predetermined intervals to attend to time critical activities.
Generated by hardware faults e.g. power failure
Can be generated by error conditions within user program
Types of Scheduler:
High-level: This controls the admission of jobs into the system and their conversion into processes. Processes are put in the READY queue.
Low-level: This is invoked when the current process relinquishes the processor. It is also involved when the process incurs an I/O runs.
Gary Nutt, Operating Systems, A Modern Perspective, Printed 1997, pg129-150
Ian Hyslop, Chris Imafidon, Systems Integration Handbook, UEL., 2002.
William Buchanan, Distributed Systems and Networks, Printed 2000, pg 58 -88
William Stalling, Operating System, Internals and Design Principles, Third Edition, pg 101
Designed by: Felix U. Igbinehi