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OS/2 Distributed File System Client Interrupt 3 Utility

IP.com Disclosure Number: IPCOM000115708D
Original Publication Date: 1995-Jun-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Ault, MB: AUTHOR [+4]

Abstract

A method for passing control to a software debugger from the OS/2* Distributed File System (DFS) client. A special .EXE file issues a DosFSCtl to the DFS client's IFS driver. When serviced by the DFS client code running at ring 3, this request results in a software interrupt 3.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 75% of the total text.

OS/2 Distributed File System Client Interrupt 3 Utility

      A method for passing control to a software debugger from the
OS/2* Distributed File System (DFS) client.  A special .EXE file
issues a DosFSCtl to the DFS client's IFS driver.  When serviced by
the DFS client code running at ring 3, this request results in a
software interrupt 3.

      The OS/2 DFS client consists of a number of executable files.
It accepts file system requests through its own Installable File
System (IFS) driver at ring 0.  However, since the bulk of the DFS
client code must run at ring 3 in order to access DCE core component
services, it is necessary for the IFS driver to queue file system
requests for servicing by a ring 3 DFS client process.

      The ring 3 process consists of several threads of execution to
handle diverse DFS client functions such as: client initialization
and termination, cache management, token management, request
servicing, etc.

      When a problem occurs in the code, it is usually not obvious
what the cause of the failure is.  The state of the DFS client code
must be examined.  The symbolic debugger used by the DFS development
team did not provide a HOT-KEY capability which allowed the
programmer to halt the execution of the DFS ring 3 process and
examine the state of the DFS client.  A technique was required to
"break-in" when a failure occured.

      The DFS team wrote a small utility program named INT3.EXE.
This program generates a spec...