Browse Prior Art Database

Methodology for Optimal Memory Use in Communications

IP.com Disclosure Number: IPCOM000115962D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Burrows, TL: AUTHOR [+2]

Abstract

CPI Communications (CPI-C), also known as the SAA communications interface, provides a programming interface that allows program-to-program communications using Systems Network Architecture (SNA) logical unit 6.2 (LU 6.2). The CPI-C APIs are a common programming interface for LU 6.2/APPC communications for many dissimilar platforms. This disclosure deals with CPI-C and its limitations on the OS/2* environment. CPI-C is very useful in developing a portable communications vehicle. It is a relatively portable transport; however, it does have its limitations. CPI-C's main OS/2 limitation is its memory use in regards to performance.

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Methodology for Optimal Memory Use in Communications

      CPI Communications (CPI-C), also known as the SAA
communications interface, provides a programming interface that
allows program-to-program communications using Systems Network
Architecture (SNA) logical unit 6.2 (LU 6.2).  The CPI-C APIs are a
common programming interface for LU 6.2/APPC communications for many
dissimilar platforms.  This disclosure deals with CPI-C and its
limitations on the OS/2* environment.  CPI-C is very useful in
developing a portable communications vehicle.  It is a relatively
portable transport; however, it does have its limitations.  CPI-C's
main OS/2 limitation is its memory use in regards to performance.

      To perform the actual data transfer, CPI-C needs its own memory
which it must allocate every time data is to be sent to a target
system.  Typically, a block of private memory is passed to the CPI-C
API.  CPI-C must then allocate another block of memory the same size,
then copy the callers data into it.  Shared "Givable" memory is the
other type of memory which the caller can pass to the CPI-C API.
With shared memory, the CPI-C API can simply use the callers memory
to transmit the data, versus re-allocating an entire block of memory.
The problem here is that shared memory is a very expensive commodity
in the performance market.

      This problem is compounded for every CPI-C conversation on the
OS/2 workstation.  In today's complex client/server configuration...