Pathmaker Programming Guide

The Structure of Pathmaker Custom Services and Servers
Creating Services and Servers
4–10 067868 Tandem Computers Incorporated
Generating services as COBOL85 directly contained programs provides modularity for
each service and independence between services, reducing the possibility of conflicts
between services packaged together into a single server. For example, you can write
the Working-Storage Section of each service completely independently, without cross-
checking variable names used in other service modules for possible conflicts.
The Pathmaker product compiles the server using the COBOL85 compiler. Generating
custom services as COBOL85 directly contained programs affects the generated server
in the following ways:
You cannot share Working-Storage items between services. (Although never a
recommended practice, sharing Working-Storage items between more than one
service was possible in earlier releases of the Pathmaker product.)
The Pathmaker product opens Enscribe files used by only one service in a server
within that service. Files used by more than one service are opened in the server.
That is, a file that needs to be opened by more than one service is opened in the
server when the following conditions are true:
The file must be the same physical file with the same logical file name and the
same open mode in each service to share an open. There are four open modes:
I Input, which indicates read only
O Output, which indicates write only
IO Input/Output, which indicates read and write
EX Extend, which indicates write following any existing data
If another service or services have the same physical file with the same logical
file name but a different open mode, the group with the most services is the
one that will be opened in the server. For example:
Service
Name
Physical File
Name
Logical File
Name
Open
Mode
Service1 LF1 Record1 I <−− Open in Service
Service2 LF1 Record1 I <−− Open in Service
Service3 LF1 Record1 O
Service4 LF1 Record1 O <−− Open in Server
Service5 LF1 Record1 O
The LF1 file is opened once in the server with the open mode O and two
internal opens with open mode I, one in Service1, and the other in Service2.
When using NonStop SQL files, all file opens are performed by NonStop SQL.