[Info-vax] Returning data from Cobol AST routine.

[Arne Vajhøj]

On 9/21/2021 5:21 PM, Jan-Erik Söderholm wrote:
> Den 2021-09-21 kl. 20:47, skrev abrsvc:
>> On Tuesday, September 21, 2021 at 2:22:28 PM UTC-4, Dave Froble wrote:
>>> Then comes the question of whether the AST would actually perform any
>>> required actions, or just interrupt the program and have the program
>>> handle the processing.
>>>
>>> Is the required actions simple enough and quick enough to have the AST
>>> routine perform the work?
>>>
>>> For sharing data, what I have not tried, but I'd be tempted, is to
>>> declare some structure, in Basic it would be a RECORD, and pass the
>>> address (By Ref) to the AST routine, which also would have an identical
>>> RECORD definition, such that the two (main and AST routine) can both
>>> share the data in the structure. All that would be required, I think,
>>> is some variable that can be passed, By Ref, to the AST routine.
>>
>> I agree with Dave, and as long as the data area is only accessed by one
>> execution stream at a time, it should be OK.  I think that the issue is
>> whether or not another can interrupt the processing of the first.
> 
> But if you haven't made a new QUI, there cannot be any new AST, can there?
> 
>> In this case, as long as the incoming record is processed prior to any
>> issuance of another QIO, it should be OK.
> 
> Ah, OK. What I wrote... :-)
> 
>> You run the risk of filling up the mailbox with records, but from the
>> initial request, these records should be fairly infrequent.
> 
> Say, each 2 min. But when they arrive, we want a 1 sec response time
> on the screen managed by this application. Today this application is
> looping and polling some data each 1 sec. So it puts a constant load
> ("backround noice") on the system and on Rdb. Even when the system is
> idle, Rdb has 10-20 transactions per second, just from the polling.
> The application is run on 10-20 screens.
> 
> Trying to find a better design, now that we hav a need for some
> major application redesign anyway for other reasons.
> 
> And, if we do have any non-AST-compatible code in the main code, I'm
> also looking for some disable/enable AST functions. They are probably
> there, just have to look it up.

You may get a much more robust solution by using your IBM MQ instead
of a VMS mailbox.

No AST's and problem with number of messages.

Arne