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Error Event Monitoring and Exception Promotion in a Multiprocessing Operating System

IP.com Disclosure Number: IPCOM000106653D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 4 page(s) / 160K

Publishing Venue

IBM

Related People

Casey, CT: AUTHOR [+3]

Abstract

All operating systems provide some facility for error handling; some operating systems provide many such facilities, each subtly but significantly different from the others. The interfaces to such facilities are typically available only to assembly language programs. Higher level languages provide their own forms of error handling as part of their run-time environments, producing a translation of the operating system facilities into the terms of the language. Such language specific error handling capabilities are limited by what is expressible within the semantics of a given programming language, and thus typically represent a rather restricted subset of the capabilities of the underlying operating system interfaces augmented by some language specific operations.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 34% of the total text.

Error Event Monitoring and Exception Promotion in a Multiprocessing Operating System

      All operating systems provide some facility for error handling;
some operating systems provide many such facilities, each subtly but
significantly different from the others.  The interfaces to such
facilities are typically available only to assembly language
programs.  Higher level languages provide their own forms of error
handling as part of their run-time environments, producing a
translation of the operating system facilities into the terms of the
language.  Such language specific error handling capabilities are
limited by what is expressible within the semantics of a given
programming language, and thus typically represent a rather
restricted subset of the capabilities of the underlying operating
system interfaces augmented by some language specific operations.

      The present invention differs from such prior art in employing
the event management services of STEVR/VM to provide a uniform error
handling facility which is available to all programs and which has
the additional features described below.

      The ability to detect, to analyze, and if appropriate to
recover from error conditions occurring during execution is a
requirement common to operating system and application program code
alike.  In a multi-threaded execution environment, it is further
necessary to be able to isolate the effects of such an error to the
thread which suffered it and whatever other threads may be sharing
its immediate environment.  Coherent analysis of the error requires
that the error handling routine be able to execute without
interference from other threads of the program containing the thread
which observed the error.  In a multiprocessing environment, such
other threads may be executing concurrently with the thread in which
the error was detected and must be halted before any error handling
operation can reasonably be undertaken.

      Analysis of the circumstances surrounding an execution error
may lead the error handling routine to one of several conclusions:

o   Recovery may be attempted after suitable changes to the
    environment.

o   Recovery is impossible and the entire program should be
    terminated.

o   Recovery is impossible but the failing thread may be terminated
    without disrupting the remainder of the program threads, which
    may continue execution.

o   The error handler cannot make a decision about recovery and must
    defer that decision to another error handler.

o   The error handler determines that a different, usually more
    severe, error has occurred than that which was initially detected
    and must alert other error handlers to that circumstance.

      This invention provides all of the above capabilities through a
novel application of the integrated event management services of

STEVR/VM.  Event management facilities additionally allow error
monitors to be tailored...