COBOL Manual for TNS/E Programs (H06.03+)

Process Initiation, Communication, and
Management
HP COBOL Manual for TNS/E Programs—520347-003
31-3
Initiating a Process From an HP COBOL Program
A process can modify its data but not its code; therefore, the operating environment
can fetch code pages needed from disk but does not need to restore them to disk; the
operating environment must rewrite data pages to disk when their physical memory is
surrendered.
The transfer of code and data pages between virtual memory on disk and physical
memory is directed by the memory manager process of the operating environment with
the help of the disk process.
The performance of any process is affected by the amount of time that is spent
managing memory instead of executing process instructions.
For more information about memory and its management, see the system description
manual for your processor.
Initiating a Process From an HP COBOL
Program
Suppose you want to make your running HP COBOL program start a new process.
This is different from having your HP COBOL program call another program with a
CALL or ENTER statement—you want to cause an entirely independent process to
execute asynchronously, perhaps on a different processor of the system or on a
different HP system. Use the CLU_PROCESS_CREATE_ routine.
For information on the CLU_PROCESS_CREATE_ routine, see the CRE
Programmer’s Guide.
Communicating With a Process
On an HP system, all processes communicate directly with one another through the
message system. The basic mechanism for access to the message system is
$RECEIVE.
Topics:
•
$RECEIVE
•
Process Names
•
Example of Simple Interprocess Communication
•
RECEIVE-CONTROL Paragraph
•
At-End Condition
•
Summary of $RECEIVE Rules
•
Simple Server Example