Browse Prior Art Database

Method for Accomplishing an Orderly Interrupt of an Executing Task in A Message Passing Operating System With Shared Data

IP.com Disclosure Number: IPCOM000121053D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 81K

Publishing Venue

IBM

Related People

Arnold, HH: AUTHOR [+3]

Abstract

A method is presented which allows a foreground process to signal a quiesced background process that it has been selected for termination at the next applicable execution point.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Method for Accomplishing an Orderly Interrupt of an Executing Task
in A Message Passing Operating System With Shared Data

      A method is presented which allows a foreground process
to signal a quiesced background process that it has been selected for
termination at the next applicable execution point.

      When a client-server software subsystem contains a client
program that is designed to operate in an operating system
environment that reports external events, such as the CTRL+BRK key
press, via an asynchronous mechanism, such as a software interrupt or
a signal, the application program can receive notification that the
end-user wants to interrupt the executing client-server conversation
by intercepting the CTRL+BRK key software interrupt or fielding the
CTRL-BRK signal and then issuing an interrupt request to the client
program to cause it to terminate the conversation in the active
process.  This mechanism is not available in a message-passing
environment such as Microsoft WINDOWS.

      In the WINDOWS programming model, notification of external
events, such as the CTRL-BRK key, is accomplished by means of
messages placed in a queue which is processed by the application in
the single- threaded process which currently owns the end-user
interface.  In this environment, no asynchronous software interrupt
or signal is generated when the CTRL+BRK keys are pressed.  In
addition, the non-preemptive programming model used in this
environment causes all processes to be quiesced until the executing
process voluntarily gives up control to WINDOWS.  This results in a
situation where, if the client program described above is waiting for
the comp...