iseries pgm call support

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

I did not fully realize until the C pgm entry discussion that external pgm call support is one of the architectural advantages of the iseries compared to linux and windows.

 

This is the 3rd such advantage that I have become aware of since joining this discussion group.

 

Here is my list of iseries architecture features that Rochester is failing to exploit:

 

1. External module call. Single level store enables a running pgm to jump to code in an external object/module. This jump can execute as quickly as jumping to code within the pgm itself. Would enable true modularization of the code of an application.

 

Not provided so as not to detract from the ile model monster.  ile must exist so the iseries can mimic lesser platforms that the iseries is striving to be compatible with.

 

 

2. External pgm call. Windows and linux dont have this capability. We do. Enables the platform to provide a heavy pgm call and a light function call. A heavy pgm call deletes overrides and closes files when it returns.  A light function has less overhead, so it runs faster. The pgm/function call distinction enables default exception handling to be customized to the type of call. 

 

The discussion of how C400 handles pgm entry, making it more pc platform like, illustrates how Rochester does not exploit the pgm call feature of the os.

 

Add iseries extensions to C. An "ExternalPgmCallMain( ... ) or Os400Main( ... ) function that can be used in place of Main( ). Allow a function to be prototyped as an external pgm. C has calling conventions such as C and PASCAL. Add OS400 as a calling convention if need be.

 

 

3. Dynamic setting of an instruction pointer to any instruction in a pgm.  Would enable debug ignore, retry, skip capabilty.  Not provided for system integrity reasons.

 

 

To ensure the success of our platform, should not all of its architectural advantages be fully exploited ?

 

 

Cheers,

 

Steve Richter