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Enable LAN Server Enterprise by Dynamic Creation of Office Systems/2 Distributed Communication Environment Threads Environment

IP.com Disclosure Number: IPCOM000116377D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 76K

Publishing Venue

IBM

Related People

Lin, S: AUTHOR [+2]

Abstract

In order to expand LAN Server (LS) functionality from a local area network to an Enterprise-wide network for Office Systems/2 (OS/2*), the Distributed Communication Environment (DCE**) is used. The integration of the LS and DCE services was accomplished with a bridge that maps the LS requests to DCE and this way, minimize the design perturbations in the LS software. Since threads is part of the native OS/2 operating system, LS Application Interfaces (API) are based on the OS/2 threads support. However, DCE is based on the portable POSIX.1c*** draft 4 threads which is quite different from the native OS/2 threads. DCE is supported through a small layer of POSIX phreads (pthreads) library which maps the pthreads API to the native threads API.

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

Enable LAN Server Enterprise by Dynamic Creation of Office Systems/2
Distributed Communication Environment Threads Environment

      In order to expand LAN Server (LS) functionality from a local
area network to an Enterprise-wide network for Office Systems/2
(OS/2*), the Distributed Communication Environment (DCE**) is used.
The integration of the LS and DCE services was accomplished with a
bridge that maps the LS requests to DCE and this way, minimize the
design perturbations in the LS software.  Since threads is part of
the native OS/2 operating system, LS Application Interfaces (API) are
based on the OS/2 threads support.  However, DCE is based on the
portable POSIX.1c*** draft 4 threads which is quite different from
the native OS/2 threads.  DCE is supported through a small layer of
POSIX phreads (pthreads) library which maps the pthreads API to the
native threads API.  In addition, this pthreads library provides data
structures to save the pthreads state.  Since the LS API make direct
calls to the OS/2 threads, a thread thus created by the OS/2 call
does not save its state as required by the DCE Pthreads layer.  As a
result one cannot invoke pthread API from a thread created by the  LS
API.  This problem can be solved by modifying the LS interfaces to
invoke the pthreads interfaces instead of the OS/2 API; but, this is
a tedious and error prone.  Another important factor to consider is
what will the legacy LAN applications do.  Do they also modify code
to access Enterprises LS?

      This invention describes a method of solving the problem
without requiring a re-write of LS or legacy software.

      To solve the problem described above, a wrapper function is
promised to wrap the LSS interfaces that invokes DCE API.  The
wrappers construct the state required by the DCE pthreads library.
The wrapper serves the following functionality:
  o  First, Check the runtime environment to see if the state
      information is needed.
  o  If so, create a super structure referred to as Thread Control
      (TCB) with required information...