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

[Dave Froble]

On 9/29/2021 9:51 PM, Stephen Hoffman wrote:
> On 2021-09-30 01:01:44 +0000, Andrew Commons said:
>
>> On Thursday, 30 September 2021 at 2:48:15 am UTC+9:30, Stephen Hoffman
>> wrote:
>>> On 2021-09-29 09:12:20 +0000, Andrew Commons said:
>>
>>> INSQUE and REMQUE are interruptable. Best use equivalent the
>>> interlocked queue operations INSQ*I and REMQ*I. Which are not.
>>>
>> The distinction between the instructions is the type of queue they
>> handle.
>>
>> From the manual:
>>
>> "Both INSQUE and REMQUE are implemented as noninterruptible
>> instructions."
>
> Yeah, you're right. INSQUE and REMQUE are non-interruptible within the
> context of a single processor. But they're concurrent within the context
> of a multiprocessor. And with no visibility within the multiprocessor
> memory caching. Which in aggregate leads to some hard-to-debug surprises.

Yeah, multi-processors, and multi-cores, really changes the game.  Some 
concepts from the single CPU era just don't work too well anymore.


-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
DFE Ultralights, Inc.
170 Grimplin Road
Vanderbilt, PA  15486