Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[David Crayford]

> On 17 Jul 2023, at 12:44 pm, Farley, Peter 
> <031df298a9da-dmarc-requ...@listserv.ua.edu> wrote:
> 
> Dave,
> 
> It may well be that the python V3.9.2 on the Zxplore system is “broken” as 
> you suggest, but getting a dump that proves it to the Zxplore admins still 
> could help goad them to more rapidly upgrade the python that is available 
> there.  I don’t see that as a useless exercise or as wasting time chasing at 
> shadows.
> 
> Nailing down the root cause of an issue is not useless.

So you expect the maintainers of ibm_db to identify the underlying cause, which 
is broken Python 3.9.2? I find that expectation unreasonable. Perhaps you 
should consider opening a case with IBM to address this issue. However, I can 
provide you with insight into what their response might be: "Python 3.9.2 is no 
longer supported; please upgrade Python to the latest version." Another concern 
is that you are utilizing a system where you lack control or influence over the 
application of maintenance.

The assumption that Python 3.9.2 is stable may not hold true. Since it is 
unsupported and no longer available for download, it raises questions about how 
the Rocket developers are able to test it in the first place.


> 
> Peter
> 
> From: IBM Mainframe Discussion List  On Behalf Of 
> David Crayford
> Sent: Sunday, July 16, 2023 7:46 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS
> 
> 
> It seems to me that the Zxplore Python is badly broken and has major issues 
> with codepage translation. we’ve seen this before when you opened an issue 
> for pyzfile.  I’m going to update the ticket to that effect so the 
> maintainers don’t waste time chasing shadows.
> 
> 
> 
>> On 17 Jul 2023, at 3:57 am, Farley, Peter 
>> <031df298a9da-dmarc-requ...@listserv.ua.edu>
>>  wrote:
> 
>> 
> 
>> Peter,
> 
>> 
> 
>> A CEEDUMP was in fact supplied to the ibmdb team on github in the initial 
>> error report that I filed there.  I generate a CEEDUMP in my $HOME directory 
>> every time I execute the example python script.
> 
>> 
> 
>> I don't think any of the ibmdb team has reviewed the dump that I submitted 
>> as of yet, or at least none have yet replied to my error report with any 
>> questions concerning the contents of that dump.
> 
>> 
> 
>> Peter
> 
>> 
> 
>> From: IBM Mainframe Discussion List 
>> mailto:IBM-MAIN@LISTSERV.UA.EDU>> On Behalf Of 
>> Peter Relson
> 
>> Sent: Sunday, July 16, 2023 9:01 AM
> 
>> To: IBM-MAIN@LISTSERV.UA.EDU
> 
>> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS
> 
>> 
> 
>> It's not expected that a SLIP dump is required to debug an application error 
>> (whether it's a segment fault or anything else). Quite the reverse.
> 
>> 
> 
>> So in what way was the CEEDUMP and/or transaction dump not adequate?  That 
>> should be brought to the attention of the LE team.
> 
>> 
> 
>> Peter Relson
> 
>> 
> 
>> z/OS Core Technology Design
> 
>> 
> 
> --
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> This message and any attachments are intended only for the use of the 
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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Farley, Peter]

Dave,

It may well be that the python V3.9.2 on the Zxplore system is “broken” as you 
suggest, but getting a dump that proves it to the Zxplore admins still could 
help goad them to more rapidly upgrade the python that is available there.  I 
don’t see that as a useless exercise or as wasting time chasing at shadows.

Nailing down the root cause of an issue is not useless.

Peter

From: IBM Mainframe Discussion List  On Behalf Of 
David Crayford
Sent: Sunday, July 16, 2023 7:46 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS


It seems to me that the Zxplore Python is badly broken and has major issues 
with codepage translation. we’ve seen this before when you opened an issue for 
pyzfile.  I’m going to update the ticket to that effect so the maintainers 
don’t waste time chasing shadows.



> On 17 Jul 2023, at 3:57 am, Farley, Peter 
> <031df298a9da-dmarc-requ...@listserv.ua.edu>
>  wrote:

>

> Peter,

>

> A CEEDUMP was in fact supplied to the ibmdb team on github in the initial 
> error report that I filed there.  I generate a CEEDUMP in my $HOME directory 
> every time I execute the example python script.

>

> I don't think any of the ibmdb team has reviewed the dump that I submitted as 
> of yet, or at least none have yet replied to my error report with any 
> questions concerning the contents of that dump.

>

> Peter

>

> From: IBM Mainframe Discussion List 
> mailto:IBM-MAIN@LISTSERV.UA.EDU>> On Behalf Of 
> Peter Relson

> Sent: Sunday, July 16, 2023 9:01 AM

> To: IBM-MAIN@LISTSERV.UA.EDU

> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS

>

> It's not expected that a SLIP dump is required to debug an application error 
> (whether it's a segment fault or anything else). Quite the reverse.

>

> So in what way was the CEEDUMP and/or transaction dump not adequate?  That 
> should be brought to the attention of the LE team.

>

> Peter Relson

>

> z/OS Core Technology Design

>

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[David Crayford]

It seems to me that the Zxplore Python is badly broken and has major issues 
with codepage translation. we’ve seen this before when you opened an issue for 
pyzfile.  I’m going to update the ticket to that effect so the maintainers 
don’t waste time chasing shadows. 

> On 17 Jul 2023, at 3:57 am, Farley, Peter 
> <031df298a9da-dmarc-requ...@listserv.ua.edu> wrote:
> 
> Peter,
> 
> A CEEDUMP was in fact supplied to the ibmdb team on github in the initial 
> error report that I filed there.  I generate a CEEDUMP in my $HOME directory 
> every time I execute the example python script.
> 
> I don't think any of the ibmdb team has reviewed the dump that I submitted as 
> of yet, or at least none have yet replied to my error report with any 
> questions concerning the contents of that dump.
> 
> Peter
> 
> From: IBM Mainframe Discussion List  On Behalf Of 
> Peter Relson
> Sent: Sunday, July 16, 2023 9:01 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS
> 
> 
> 
> It's not expected that a SLIP dump is required to debug an application error 
> (whether it's a segment fault or anything else). Quite the reverse.
> 
> 
> 
> So in what way was the CEEDUMP and/or transaction dump not adequate?  That 
> should be brought to the attention of the LE team.
> 
> 
> 
> Peter Relson
> 
> z/OS Core Technology Design
> 
> --
> 
> 
> This message and any attachments are intended only for the use of the 
> addressee and may contain information that is privileged and confidential. If 
> the reader of the message is not the intended recipient or an authorized 
> representative of the intended recipient, you are hereby notified that any 
> dissemination of this communication is strictly prohibited. If you have 
> received this communication in error, please notify us immediately by e-mail 
> and delete the message and any attachments from your system.
> 
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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Farley, Peter]

The Zxplore admin just advised me that the definitions they had set up to 
provide DASD space for an SVCDUMP may have expired at the last IPL they did a 
week ago.  I will report back when he finds an answer to that question.

Peter

From: IBM Mainframe Discussion List  On Behalf Of 
Farley, Peter
Sent: Sunday, July 16, 2023 3:49 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS



This is the latest SLIP setup from today which did not catch the abend when the 
python script is executed from an ssh login to z/OS on the Zxplore system:



SLIP 
SET,ID=PJF1,JOBNAME=Z02446*,COMP=0C4,ACTION=SVCD,AL=(H,P,S),SDATA=(ALLNUC,PSA,RGN,LPA,CSA,SQA,TRT,GRSQ,SUM),END



Peter



From: IBM Mainframe Discussion List  On Behalf Of 
Peter Relson

Sent: Saturday, July 15, 2023 8:26 PM

To: IBM-MAIN@LISTSERV.UA.EDU

Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS



What SLIP trap did you try setting? SLIP SET,C=0C4,A=SVCD,END will catch every 
0C4 that occurs anywhere. That wouldn't be what I'd want for a SLIP trap (it's 
too broad so will hit on things you don't want). But it would work. But only 
once (default match limit for A=SVCD is one). Either there was no 0C4 or your 
SLIP trap asked to filter out the 0C4 that happened or your SLIP trap is not 
active (perhaps because of a previous match reaching the match limit). I can 
think of a lot of ways to create a SLIP trap that would not match.



Gil wrote







No assistance, but an observation that SLIP has appeared to have been



specified before fork() came to MVS.



It would be a good Idea to enhance SLIP to recognize all the progeny



of a job step.







I wouldn't bet that SLIP needs any enhancement in that arena. But perhaps once 
we hear from the OP what he tried that did not work we will form a new opinion.



Peter Relson



z/OS Core Technology Design



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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Farley, Peter]

Mike,

I suspect I do not have the authority to run GTF on the Zxplore system, not to 
mention I have no knowledge of how to run it in the first place.  My userid on 
Zxplore is just like any of the other “students” registered to learn there, 
with deliberately limited authority.

It would fall to the Zxplore admin to both change the SLIP to use the DEBUG 
parameter, communicate with me to run the failing process, and then run the GTF 
trace to see what happened.  That may be a bit much to ask of the admin, given 
the many other issues he has to deal with on that system.  As I said earlier, 
the ibmdb package is NOT on their list of “we will support that for student 
use” products.  The support I have been getting with setting up the SLIP is 
already outside of their usual procedures, for which I have been grateful.

I will ask if the process you suggest is within his time availability.

Peter

From: IBM Mainframe Discussion List  On Behalf Of 
Mike Shaw
Sent: Sunday, July 16, 2023 4:26 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS



Peter,



If you can run GTF on the Zxplore system and capture the output, you might

want to try to use the DEBUG option of the SLIP SET command:











Mike Shaw

MVS/QuickRef Support Group

Chicago-Soft, Ltd.





On Sun, Jul 16, 2023 at 3:48 PM Farley, Peter <

031df298a9da-dmarc-requ...@listserv.ua.edu> wrote:



> This is the latest SLIP setup from today which did not catch the abend

> when the python script is executed from an ssh login to z/OS on the Zxplore

> system:

>

>

> SLIP

> SET,ID=PJF1,JOBNAME=Z02446*,COMP=0C4,ACTION=SVCD,AL=(H,P,S),SDATA=(ALLNUC,PSA,RGN,LPA,CSA,SQA,TRT,GRSQ,SUM),END

>

>

> Peter

>

> From: IBM Mainframe Discussion List  On Behalf

> Of Peter Relson

> Sent: Saturday, July 15, 2023 8:26 PM

> To: IBM-MAIN@LISTSERV.UA.EDU

> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS

>

> What SLIP trap did you try setting? SLIP SET,C=0C4,A=SVCD,END will catch

> every 0C4 that occurs anywhere. That wouldn't be what I'd want for a SLIP

> trap (it's too broad so will hit on things you don't want). But it would

> work. But only once (default match limit for A=SVCD is one). Either there

> was no 0C4 or your SLIP trap asked to filter out the 0C4 that happened or

> your SLIP trap is not active (perhaps because of a previous match reaching

> the match limit). I can think of a lot of ways to create a SLIP trap that

> would not match.

>

> Gil wrote

>

> 

>

> No assistance, but an observation that SLIP has appeared to have been

>

> specified before fork() came to MVS.

>

> It would be a good Idea to enhance SLIP to recognize all the progeny

>

> of a job step.

>

> 

>

> I wouldn't bet that SLIP needs any enhancement in that arena. But perhaps

> once we hear from the OP what he tried that did not work we will form a new

> opinion.

>

> Peter Relson

>

> z/OS Core Technology Design

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Mike Shaw]

Peter,

If you can run GTF on the Zxplore system and capture the output, you might
want to try to use the DEBUG option of the SLIP SET command:


DEBUG



For a SLIP SET trap, allows you to determine why a trap that you set is

not working as you expected by indicating which of the conditions you

established is not being met. DEBUG provides trap information each time

the trap is tested rather than just when it matches.



The generalized trace facility (GTF) and its trace option for SLIP

records must be active. Each DEBUG trace record contains SLIP

information plus two bytes: the first byte contains a value indicating

the failing parameter and the second byte contains zero.



For a description of the DEBUG values, see the SLIP debug trace record

for GTF in z/OS MVS Diagnosis: Tools and Service Aids.



Mike Shaw
MVS/QuickRef Support Group
Chicago-Soft, Ltd.


On Sun, Jul 16, 2023 at 3:48 PM Farley, Peter <
031df298a9da-dmarc-requ...@listserv.ua.edu> wrote:

> This is the latest SLIP setup from today which did not catch the abend
> when the python script is executed from an ssh login to z/OS on the Zxplore
> system:
>
>
> SLIP
> SET,ID=PJF1,JOBNAME=Z02446*,COMP=0C4,ACTION=SVCD,AL=(H,P,S),SDATA=(ALLNUC,PSA,RGN,LPA,CSA,SQA,TRT,GRSQ,SUM),END
>
>
> Peter
>
> From: IBM Mainframe Discussion List  On Behalf
> Of Peter Relson
> Sent: Saturday, July 15, 2023 8:26 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS
>
>
>
> What SLIP trap did you try setting? SLIP SET,C=0C4,A=SVCD,END will catch
> every 0C4 that occurs anywhere. That wouldn't be what I'd want for a SLIP
> trap (it's too broad so will hit on things you don't want). But it would
> work. But only once (default match limit for A=SVCD is one). Either there
> was no 0C4 or your SLIP trap asked to filter out the 0C4 that happened or
> your SLIP trap is not active (perhaps because of a previous match reaching
> the match limit). I can think of a lot of ways to create a SLIP trap that
> would not match.
>
>
>
> Gil wrote
>
> 
>
> No assistance, but an observation that SLIP has appeared to have been
>
> specified before fork() came to MVS.
>
>
>
> It would be a good Idea to enhance SLIP to recognize all the progeny
>
> of a job step.
>
> 
>
>
>
> I wouldn't bet that SLIP needs any enhancement in that arena. But perhaps
> once we hear from the OP what he tried that did not work we will form a new
> opinion.
>
>
>
> Peter Relson
>
> z/OS Core Technology Design
>
> --
>
>
> This message and any attachments are intended only for the use of the
> addressee and may contain information that is privileged and confidential.
> If the reader of the message is not the intended recipient or an authorized
> representative of the intended recipient, you are hereby notified that any
> dissemination of this communication is strictly prohibited. If you have
> received this communication in error, please notify us immediately by
> e-mail and delete the message and any attachments from your system.
>
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> For IBM-MAIN subscribe / signoff / archive access instructions,
> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
>

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Farley, Peter]

Peter,

A CEEDUMP was in fact supplied to the ibmdb team on github in the initial error 
report that I filed there.  I generate a CEEDUMP in my $HOME directory every 
time I execute the example python script.

I don't think any of the ibmdb team has reviewed the dump that I submitted as 
of yet, or at least none have yet replied to my error report with any questions 
concerning the contents of that dump.

Peter

From: IBM Mainframe Discussion List  On Behalf Of 
Peter Relson
Sent: Sunday, July 16, 2023 9:01 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS



It's not expected that a SLIP dump is required to debug an application error 
(whether it's a segment fault or anything else). Quite the reverse.



So in what way was the CEEDUMP and/or transaction dump not adequate?  That 
should be brought to the attention of the LE team.



Peter Relson

z/OS Core Technology Design

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Farley, Peter]

This is the latest SLIP setup from today which did not catch the abend when the 
python script is executed from an ssh login to z/OS on the Zxplore system:


SLIP 
SET,ID=PJF1,JOBNAME=Z02446*,COMP=0C4,ACTION=SVCD,AL=(H,P,S),SDATA=(ALLNUC,PSA,RGN,LPA,CSA,SQA,TRT,GRSQ,SUM),END


Peter

From: IBM Mainframe Discussion List  On Behalf Of 
Peter Relson
Sent: Saturday, July 15, 2023 8:26 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS



What SLIP trap did you try setting? SLIP SET,C=0C4,A=SVCD,END will catch every 
0C4 that occurs anywhere. That wouldn't be what I'd want for a SLIP trap (it's 
too broad so will hit on things you don't want). But it would work. But only 
once (default match limit for A=SVCD is one). Either there was no 0C4 or your 
SLIP trap asked to filter out the 0C4 that happened or your SLIP trap is not 
active (perhaps because of a previous match reaching the match limit). I can 
think of a lot of ways to create a SLIP trap that would not match.



Gil wrote



No assistance, but an observation that SLIP has appeared to have been

specified before fork() came to MVS.



It would be a good Idea to enhance SLIP to recognize all the progeny

of a job step.





I wouldn't bet that SLIP needs any enhancement in that arena. But perhaps once 
we hear from the OP what he tried that did not work we will form a new opinion.



Peter Relson

z/OS Core Technology Design

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Re: C++ coroutines are recent, and difficult?

[Seymour J Metz]

Think generators and iterators.


From: IBM Mainframe Discussion List  on behalf of 
Rupert Reynolds 
Sent: Sunday, July 16, 2023 2:03 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: C++ coroutines are recent, and difficult?

Oh I see!
Thanks. Yes, that would make sense, although from my trivial understanding
it might make coroutines less useful for my kind of work.

Roops

On Sun, 16 Jul 2023, 12:08 Seymour J Metz,  wrote:

> With ATTACH, you need to play games to prevent two tasks from running
> concurrently on two CPUs. With coroutines, you have multiples contexts
> within a single thread; there is no need for explicit interlocking.
>
>
> --
> Shmuel (Seymour J.) Metz
> http://mason.gmu.edu/~smetz3
>
> 
> From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf
> of Rupert Reynolds [rreyno...@cix.co.uk]
> Sent: Sunday, July 16, 2023 6:01 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: C++ coroutines are recent, and difficult?
>
> I must have missed the point of something, because on first reading, it's
> analogous to what we could do with ATTACH, ECB and WAIT in assembly under
> z/OS and MVS, or the equivalents in PL/I and COBOL (I assume) where we have
> a subtask which can wait for an event and then resume operation from its
> suspended state (line of code after the WAIT), or the parent task can
> suspend and resume the subtask when its services are required again.
>
> I also watched this video and got the same impression
> https://youtu.be/nGexHRT1GY0
>
> I know it's more difficult to specify when you're making a portable
> language, but I feel both cheated and glad I didn't spend more time
> learning C++.
>
> Can anyone suggest what else C++ coroutines offer, please?
>
> TVMIA
> Roops
>
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Re: C++ coroutines are recent, and difficult?

[Rupert Reynolds]

Oh I see!
Thanks. Yes, that would make sense, although from my trivial understanding
it might make coroutines less useful for my kind of work.

Roops

On Sun, 16 Jul 2023, 12:08 Seymour J Metz,  wrote:

> With ATTACH, you need to play games to prevent two tasks from running
> concurrently on two CPUs. With coroutines, you have multiples contexts
> within a single thread; there is no need for explicit interlocking.
>
>
> --
> Shmuel (Seymour J.) Metz
> http://mason.gmu.edu/~smetz3
>
> 
> From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf
> of Rupert Reynolds [rreyno...@cix.co.uk]
> Sent: Sunday, July 16, 2023 6:01 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: C++ coroutines are recent, and difficult?
>
> I must have missed the point of something, because on first reading, it's
> analogous to what we could do with ATTACH, ECB and WAIT in assembly under
> z/OS and MVS, or the equivalents in PL/I and COBOL (I assume) where we have
> a subtask which can wait for an event and then resume operation from its
> suspended state (line of code after the WAIT), or the parent task can
> suspend and resume the subtask when its services are required again.
>
> I also watched this video and got the same impression
> https://youtu.be/nGexHRT1GY0
>
> I know it's more difficult to specify when you're making a portable
> language, but I feel both cheated and glad I didn't spend more time
> learning C++.
>
> Can anyone suggest what else C++ coroutines offer, please?
>
> TVMIA
> Roops
>
> --
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Re: C++ coroutines are recent, and difficult?

[Seymour J Metz]

Coroutines were never intended to replace tasks, despite what wiki implies in 
the lead. See Conway, Melvin E. (July 1963). "Design of a Separable 
Transition-diagram Compiler" (PDF). Communications of the ACM. ACM. 6 (7): 
396–408. doi:10.1145/33.366704.  at 



From: IBM Mainframe Discussion List  on behalf of 
Paul Gilmartin <042bfe9c879d-dmarc-requ...@listserv.ua.edu>
Sent: Sunday, July 16, 2023 12:17 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: C++ coroutines are recent, and difficult?

On Sun, 16 Jul 2023 11:08:51 +, Seymour J Metz wrote:

>With ATTACH, you need to play games to prevent two tasks from running 
>concurrently on two CPUs. With coroutines, you have multiples contexts within 
>a single thread; there is no need for explicit interlocking.
>
Il a les défauts de ses qualités.  At times one wants things to run concurrently
yet share storage, locking only when necessary for integrity.  Even with only
one CPU locking is sometimes necessary because of preemptive dispatching.

--
gil

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Re: C++ coroutines are recent, and difficult?

[Paul Gilmartin]

On Sun, 16 Jul 2023 11:08:51 +, Seymour J Metz wrote:

>With ATTACH, you need to play games to prevent two tasks from running 
>concurrently on two CPUs. With coroutines, you have multiples contexts within 
>a single thread; there is no need for explicit interlocking.
>
Il a les défauts de ses qualités.  At times one wants things to run concurrently
yet share storage, locking only when necessary for integrity.  Even with only
one CPU locking is sometimes necessary because of preemptive dispatching.

-- 
gil

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[Peter Relson]

It's not expected that a SLIP dump is required to debug an application error 
(whether it's a segment fault or anything else). Quite the reverse.

So in what way was the CEEDUMP and/or transaction dump not adequate?  That 
should be brought to the attention of the LE team.

Peter Relson
z/OS Core Technology Design


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Re: C++ coroutines are recent, and difficult?

[Seymour J Metz]

With ATTACH, you need to play games to prevent two tasks from running 
concurrently on two CPUs. With coroutines, you have multiples contexts within a 
single thread; there is no need for explicit interlocking.


--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3


From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of 
Rupert Reynolds [rreyno...@cix.co.uk]
Sent: Sunday, July 16, 2023 6:01 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: C++ coroutines are recent, and difficult?

I must have missed the point of something, because on first reading, it's
analogous to what we could do with ATTACH, ECB and WAIT in assembly under
z/OS and MVS, or the equivalents in PL/I and COBOL (I assume) where we have
a subtask which can wait for an event and then resume operation from its
suspended state (line of code after the WAIT), or the parent task can
suspend and resume the subtask when its services are required again.

I also watched this video and got the same impression
https://youtu.be/nGexHRT1GY0

I know it's more difficult to specify when you're making a portable
language, but I feel both cheated and glad I didn't spend more time
learning C++.

Can anyone suggest what else C++ coroutines offer, please?

TVMIA
Roops

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Re: A question about CPU usage on z/OS

[Seymour J Metz]

Every thing should be as simple as possible but no simpler. A non-zero wait 
count in the current RB of a task is only one of the reasons that it may not 
eligible to run.

Address space ineligible
TCB nondispatchable
Current RB has wait count > 0


--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3


From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of 
Brian Westerman [brian_wester...@syzygyinc.com]
Sent: Sunday, July 16, 2023 2:39 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: A question about CPU usage on z/OS

Everything in a wait is not "eligible" to run.   That's pretty much the 
definition of wait. :)

Brian

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C++ coroutines are recent, and difficult?

[Rupert Reynolds]

I must have missed the point of something, because on first reading, it's
analogous to what we could do with ATTACH, ECB and WAIT in assembly under
z/OS and MVS, or the equivalents in PL/I and COBOL (I assume) where we have
a subtask which can wait for an event and then resume operation from its
suspended state (line of code after the WAIT), or the parent task can
suspend and resume the subtask when its services are required again.

I also watched this video and got the same impression
https://youtu.be/nGexHRT1GY0

I know it's more difficult to specify when you're making a portable
language, but I feel both cheated and glad I didn't spend more time
learning C++.

Can anyone suggest what else C++ coroutines offer, please?

TVMIA
Roops

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Re: A question about CPU usage on z/OS

[Brian Westerman]

Everything in a wait is not "eligible" to run.   That's pretty much the 
definition of wait. :)

Brian

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Re: How to set a SLIP to catch S0C4 in OMVS separate AS

[David Crayford]

Here are our LE settings. It seems DYNDUMP is significant, you can specify this 
as a runtime option https://www.ibm.com/docs/en/zos/2.4.0?topic=ulero-dyndump.

CEEDUMP(60,SYSOUT=*,FREE=END, 
  SPIN=UNALLOC)   
DYNDUMP(*USERID.CEEDUMP,DYNAMIC,TDUMP)
ENVAR("TZ=GMT-8") 
NATLANG(ENU)  
TERMTHDACT(UADUMP,,)  

Peter, 

I strongly suspect this abend is due to a build issue. When Ibm_db is installed 
using pip3 it is compiled from source as it’s a cross-platform library. As I 
previously mentioned, there may be compatibility issues depending on how the 
environment is setup. I urge you to reach out to the admins and ask them how 
they built this package. I notice that you have opened an issue in Github and 
that the Rocket devs are involved. Before we start diving into dumps can you 
please confirm the environment is sound first. 

https://www.ibm.com/docs/en/python-zos/3.9?topic=information-using-distutils-module

>> Note: There might be compatibility issues when mixing xlc and 
xlclang for compiled code and thus only one should be used consistently for 
building and linking modules.

> On 16 Jul 2023, at 9:18 am, David Crayford  wrote:
> 
> Are you sure you don’t have a dump? LE is usually configured with 
> TERMTHDACT(UADUMP) which creates a transaction (SYSMDUMP). Look in the 
> syslog. Set the following environment variable to enable dumps by default. 
> 
> export _CEE_RUNOPTS=FILETAG(AUTOCVT,AUTOTAG) TERMTHDACT(UADUMP) 
> ABTERMENC(ABEND)
> 
> FYI, ibm_db is in beta status so I wouldn’t consider using it for real work. 
> We had a look at this abend a few weeks ago but couldn’t re-create it. It 
> only happens with Python3.9 which we don’t have installed. We suspected an 
> ABI problem where the package was built using a different compiler to the 
> Python VM. The IBM XL C compiler is not compatible with IBM Open XL C/C++. 
> 
>> On 16 Jul 2023, at 2:17 am, Farley, Peter 
>> <031df298a9da-dmarc-requ...@listserv.ua.edu> wrote:
>> 
>> Thanks for trying to help Jon, but “IBM” hasn’t *officially* looked at 
>> anything.  The python ibmdb team is an open source collective (perhaps 
>> including some IBM employees, but I do not know that for sure) and is not 
>> “official” IBM support at all.  One of the ibmdb team has asked for an 
>> SVCDUMP as they may have seen this error previously but could not follow up 
>> on it at that time.
>> 
>> I do not have access to set the SLIP to catch this abend, I have to rely on 
>> the admins at the Zxplore system to do that, and they are not experts 
>> either.  Zxplore is a “student learning” system that IBM runs in the cloud 
>> but solving a problem with the python ibmdb code is not very high on their 
>> list of priorities, though they have been trying to help here.  I am not 
>> dealing with an experienced z/OS sysprog on Zxplore for this task, just a 
>> system “administrator” who has considerable authority on the system.
>> 
>> The python program stops altogether after the abend even with a try/except 
>> (at least I think it does – I will double check that) so there is no chance 
>> to output anything after the abend.  If it turns out that a try/except works 
>> I will try getting an output to /dev/console after the abend and see if that 
>> can help generate a dump.  I am not sure that an SVCDUMP after the python 
>> program terminates would be at all helpful, but I am not an expert in that 
>> area either.
>> 
>> Again, thanks for trying to help.
>> 
>> Peter
>> 
>> From: IBM Mainframe Discussion List  On Behalf Of 
>> Jon Perryman
>> Sent: Saturday, July 15, 2023 11:28 AM
>> To: IBM-MAIN@LISTSERV.UA.EDU
>> Subject: Re: How to set a SLIP to catch S0C4 in OMVS separate AS
>> 
>> As you discovered, S0C4 SLIPs are at the best of times a pain in the a$$. 
>> S0C4 is difficult because it has a real use which is to determine if a page 
>> has been created (not just allocated). It requires multiple SLIP IGNORE 
>> which can be obtained from IBM. Since you are working with IBM support, I 
>> assume they gave you these SLIP IGNORE to be defined the SLIP SVCDUMP. It 
>> would be helpful to see the SLIPs provided by IBM.
>> I assume IBM looked at the CEEDUMP but it did not contain anything that 
>> would be useful for setting a SLIP. This leaves you with some trial and 
>> error. Without anything to go on, here's what I would look consider.
>> 1. If you repeat the abend, does it occur at the same address? If so, 
>> ADDRESS=,COND=0C4  may be your easiest option.2. If you can get quiet time 
>> on a system, you can get quiet time on the system, this would be your second 
>> choice.3. I assume you are somewhat comfortable with IPCS. If so, capture an 
>> informational dump and create  a SLIP using the information you find as 
>> follows:3A. Generate a WTO as soon as possible after the abend. Since you 
>> have Python source, code a TRY/EXCEPT which writes a message to the