Browse Prior Art Database

Blocked Messages in Memory Control Block Format

IP.com Disclosure Number: IPCOM000100497D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Goodman, DJ: AUTHOR

Abstract

Described is a method to structure a blocked message so that each sub-block is treated as a separately allocated memory element for processing. Use of this scheme requires a dynamic memory manager in the system that is able to break a large allocated memory element into many smaller ones. This is in marked contrast to a method of unblocking a blocked message into sub-blocks by allocating separate memory elements and copying the data blocks into them.

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

Blocked Messages in Memory Control Block Format

       Described is a method to structure a blocked message so
that each sub-block is treated as a separately allocated memory
element for processing.  Use of this scheme requires a dynamic memory
manager in the system that is able to break a large allocated memory
element into many smaller ones.  This is in marked contrast to a
method of unblocking a blocked message into sub-blocks by allocating
separate memory elements and copying the data blocks into them.

      The blocking of smaller data structures (called sub-blocks)
into a larger data structure (called a block) containing more than
one sub- block is a commonly used technique to efficiently package
data.  The larger blocked message is saved on disk storage or
transferred over a communications medium more efficiently than
individual sub-blocks.  Described is a way to structure the
sub-blocks in the blocked message so that when the message needs to
be unblocked, it is easily done without copying the data into
separately allocated memory elements.

      A blocked message using this scheme looks something like that
shown in the figure when it has been read into a memory element
allocated by the memory manager.  The key elements in the structure
are:
   BLOCK HEADER--Fields for keeping track of the sub-blocks.  These
include:
   BLOCK MEMORY PREFIX--Structure required by the memory manager to
keep track of free or allocated memory elements. When the block is
received or read into memory, the entire block is contained within
this element.
SUB-BLOCK COUNT--Number of sub-blocks within the total block.
           BLOCK LENGTH--Size of total block.
           OTHER FIELDS--As required.
      SUB-BLOCK--The sub-block is mad...