Reichman [reichman...@gmail.com]
Sent: Monday, March 22, 2021 11:57 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
So are BUFNO= and GETPOOL/ GETBUF related
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So are BUFNO= and GETPOOL/ GETBUF related
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of
Seymour J Metz
Sent: Monday, March 22, 2021 11:48 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
GETPOOL and FREEPOOL are also valid for QSAM
: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
If youre using GETPOOL/GETBUF then youre not doing QSAM. GETBUF is for
BSAM. You would be OPENING the file then using READ macros to read in
your records.
If youre doing QSAM, then you just issue the OPEN followed by a GET.
There
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Sun, Mar 21, 2021 at 04:54:45PM -0400, Joseph Reichman wrote:
> Just to make sure I am understanding correctly I use GETPOOL/GETBUFF
> with QSAM it will use Asynchronous/overlapped i/o right ?
You should only need DCB/OPEN
, March 21, 2021 5:45 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
So implementing asynchronous I/O in QSAM is as simple as having BUFNO= the
right number
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ist [IBM-MAIN@LISTSERV.UA.EDU] on behalf of
Charles Mills [charl...@mcn.org]
Sent: Sunday, March 21, 2021 6:40 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
Implementing overlapped I/O is what QSAM does. You don't even need to code
BUFNO. IMHO it is one of the two main poi
: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
Behalf Of Joseph Reichman
Sent: Sunday, March 21, 2021 2:46 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
So implementing asynchronous I/O in QSAM is as simple as having BUFNO= the
right number
thanks
So implementing asynchronous I/O in QSAM is as simple as having BUFNO= the
right number
thanks
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of
Michael Stein
Sent: Sunday, March 21, 2021 5:41 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Sun, Mar 21, 2021 at 04:54:45PM -0400, Joseph Reichman wrote:
> Just to make sure I am understanding correctly I use GETPOOL/GETBUFF
> with QSAM it will use Asynchronous/overlapped i/o right ?
You should only need DCB/OPEN/CLOSE/GET.
Let most everything default, QSAM knows what to do for
> Of Joe Monk
> Sent: Sunday, March 21, 2021 1:24 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Overlapped I/O completion
>
> "The queued access technique provides GET and PUT macro instructions for
> transmitting data within virtual storage. These macro instruc
: Re: Overlapped I/O completion
"The queued access technique provides GET and PUT macro instructions for
transmitting data within virtual storage. These macro instructions cause
automatic blocking and deblocking of the records stored and retrieved.
Anticipatory (look-ahead) buff
u/~smetz3
From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of
Michael Stein [m...@zlvfc.com]
Sent: Saturday, March 20, 2021 11:31 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Fri, Mar 19, 2021 at 03:35:39PM -0400, Joseph
on behalf of
Michael Stein [m...@zlvfc.com]
Sent: Saturday, March 20, 2021 11:51 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Fri, Mar 19, 2021 at 08:08:28PM -0500, Paul Gilmartin wrote:
> On Fri, 19 Mar 2021 21:50:57 +, Seymour J Metz wrote:
>
> >> Is ther
On Sun, 21 Mar 2021 10:08:13 -0500, Joel C. Ewing wrote:
>Believe it.
>
Performance is unsatisfactory.
I must do something.
BSAM is something.
Therefore I must do BSAM.
-- gil
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> From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf
> of Joseph Reichman [reichman...@gmail.com]
> Sent: Sunday, March 21, 2021 10:21 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Overlapped I/O completion
>
> I don’t under
UA.EDU
Subject: Re: Overlapped I/O completion
I don’t understand what the statement “QSAM does overlapped I/O automatically”
When I do a qsam get the physical I/O is for 1 block every get just ups a
pointer
BSAM allows me to do multiple Reads each with their own DECB
So I already initiat
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
Thank you does the number “GET” ahead I/o depend on Buffno
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Subject: Re: Overlapped I/O completion
Believe it.
Even before emulated DASD, MVS QSAM would read multiple blocks with a
single channel program to eliminate rotational delays on native DASD and
do anticipatory reads for the next set of buffers even while you were
still processing records in blocks
On 3/21/2021 7:21 AM, Joseph Reichman wrote:
I don’t understand what the statement “QSAM does overlapped I/O automatically”
When I do a qsam get the physical I/O is for 1 block every get just ups a
pointer
QSAM does overlapped I/O (and has done for many, Many, MANY years).
If you want to
Yes. Default varies by type of device.
Sent from my iPhone
> On Mar 21, 2021, at 11:08 AM, Joel C. Ewing wrote:
>
> Believe it.
>
> Even before emulated DASD, MVS QSAM would read multiple blocks with a
> single channel program to eliminate rotational delays on native DASD and
> do
Believe it.
Even before emulated DASD, MVS QSAM would read multiple blocks with a
single channel program to eliminate rotational delays on native DASD and
do anticipatory reads for the next set of buffers even while you were
still processing records in blocks from the previous read, as long as
Thank you does the number “GET” ahead I/o depend on Buffno
> On Mar 20, 2021, at 11:31 AM, Michael Stein wrote:
>
> On Fri, Mar 19, 2021 at 03:35:39PM -0400, Joseph Reichman wrote:
>> So this is what I will do
>>
>> I’ll do 3 reads in the first since i need to get myself going I’ll issue
From Jim Mulder:
Jim Mulder
2/4/17
to
There are no coding requirements for the application, When you do
a QSAM OPEN for Input, the first read-ahead I/Os are scheduled by OPEN,
and the application program can proceed without waiting after the OPEN at
least to the point of doing the first
I don’t understand what the statement “QSAM does overlapped I/O automatically”
When I do a qsam get the physical I/O is for 1 block every get just ups a
pointer
BSAM allows me to do multiple Reads each with their own DECB
So I already initiate lots of physical I/O mainly because I have lots
On Fri, 19 Mar 2021 14:09:59 -0400 Joseph Reichman
wrote:
:>When doing overlapped I/O is there a way to tell if the I/O had completed on
the subsequent reads
:>I check to see if the first fullword has been populated by the BDW
Did you try without overlapping I/O?
Post the code.
--
Binyamin
On Fri, Mar 19, 2021 at 08:08:28PM -0500, Paul Gilmartin wrote:
> On Fri, 19 Mar 2021 21:50:57 +, Seymour J Metz wrote:
>
> >> Is there any reason to do a WAIT before the CHECK?
> >EOV processing.
Normally a CHECK just waits on the ECB and does a minimal amount of
processing.
If there is
On Fri, Mar 19, 2021 at 03:58:57PM -0400, Joseph Reichman wrote:
> Data is not there after check
Most likely reason is that the READ isn't complete yet. Possibly
was never issued (yet).
BSAM works. It's not as easy to use as QSAM, nor very easy to do
overlapped I/O as QSAM (which does it
On Fri, Mar 19, 2021 at 03:35:39PM -0400, Joseph Reichman wrote:
> So this is what I will do
>
> I’ll do 3 reads in the first since i need to get myself going I’ll issue the
> WAIT using the ECB from the DECB
Limiting the pending reads to 3 will limit the performance to worse
(or at least no
On Fri, 19 Mar 2021 21:50:57 +, Seymour J Metz wrote:
>> Is there any reason to do a WAIT before the CHECK?
>EOV processing.
>
It was long ago and I no longer have the code. IIRC, I coded a CHECK,
but never a WAIT. It was specialized code, and I may not have accounted
for EOV.
What ill
LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Fri, 19 Mar 2021 12:43:38 -0700, Ed Jaffe wrote:
>On 3/19/2021 12:35 PM, Joseph Reichman wrote:
>> So this is what I will do
>>
>> I’ll do 3 reads in the first since i need to get myself going I’ll issue the
>> WAI
On Fri, 19 Mar 2021 15:58:57 -0400, Joseph Reichman wrote:
>Data is not there after check
>
WTF!?
On Fri, 19 Mar 2021 11:25:12 -0700, Ed Jaffe wrote:
>On 3/19/2021 11:09 AM, Joseph Reichman wrote:
>>...
>> I check to see if the first fullword has been populated by the BDW
>
That's called
Checks checks for eodad
Thanks
> On Mar 19, 2021, at 4:02 PM, Ed Jaffe wrote:
>
> On 3/19/2021 12:57 PM, Paul Gilmartin wrote:
>>> On Fri, 19 Mar 2021 12:43:38 -0700, Ed Jaffe wrote:
>>>
>>>
>>> Don't forget to issue CHECK after WAIT.
>>>
>> Is there any reason to do a WAIT before the
On 3/19/2021 12:57 PM, Paul Gilmartin wrote:
On Fri, 19 Mar 2021 12:43:38 -0700, Ed Jaffe wrote:
Don't forget to issue CHECK after WAIT.
Is there any reason to do a WAIT before the CHECK? I never did.
You would issue WAIT first if you were in an environment that could not
tolerate
Data is not there after check
> On Mar 19, 2021, at 3:57 PM, Paul Gilmartin
> <000433f07816-dmarc-requ...@listserv.ua.edu> wrote:
>
> On Fri, 19 Mar 2021 12:43:38 -0700, Ed Jaffe wrote:
>
>>> On 3/19/2021 12:35 PM, Joseph Reichman wrote:
>>> So this is what I will do
>>>
>>> I’ll do 3
On Fri, 19 Mar 2021 12:43:38 -0700, Ed Jaffe wrote:
>On 3/19/2021 12:35 PM, Joseph Reichman wrote:
>> So this is what I will do
>>
>> I’ll do 3 reads in the first since i need to get myself going I’ll issue the
>> WAIT using the ECB from the DECB
>> Than when I finish processing that buffer and
On 3/19/2021 12:35 PM, Joseph Reichman wrote:
So this is what I will do
I’ll do 3 reads in the first since i need to get myself going I’ll issue the
WAIT using the ECB from the DECB
Than when I finish processing that buffer and need to go to the second I/O I’ll
issue a WAIT for that
etc
On Fri, 19 Mar 2021 15:35:39 -0400, Joseph Reichman wrote:
>So this is what I will do
>
>I’ll do 3 reads in the first since i need to get myself going I’ll issue the
>WAIT using the ECB from the DECB
>Than when I finish processing that buffer and need to go to the second I/O
>I’ll issue a
Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of
> Joseph Reichman [reichman...@gmail.com]
> Sent: Friday, March 19, 2021 2:09 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Overlapped I/O completion
>
> Hi
>
> When doing overlapped I/O is there a way to tel
of
Joseph Reichman [reichman...@gmail.com]
Sent: Friday, March 19, 2021 2:09 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Overlapped I/O completion
Hi
When doing overlapped I/O is there a way to tell if the I/O had completed on
the subsequent reads
I check to see if the first fullword has been
]
Sent: Friday, March 19, 2021 2:25 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On 3/19/2021 11:09 AM, Joseph Reichman wrote:
> Hi
>
> When doing overlapped I/O is there a way to tell if the I/O had completed on
> the subsequent reads
>
> I check to see if
First byte Of DECB/ECB was x’7F’ 40 bit ( posted bit was on )
> On Mar 19, 2021, at 2:25 PM, Ed Jaffe wrote:
>
> On 3/19/2021 11:09 AM, Joseph Reichman wrote:
>> Hi
>>
>> When doing overlapped I/O is there a way to tell if the I/O had completed on
>> the subsequent reads
>>
>> I check to
On 3/19/2021 11:09 AM, Joseph Reichman wrote:
Hi
When doing overlapped I/O is there a way to tell if the I/O had completed on
the subsequent reads
I check to see if the first fullword has been populated by the BDW
The DECB that you issue CHECK against contains an actual embedded ECB at
ay, March 19, 2021 2:10 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Overlapped I/O completion
>
> Hi
>
> When doing overlapped I/O is there a way to tell if the I/O had completed on
> the subsequent reads
>
> I check to see if the first fullword has been populated
PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Overlapped I/O completion
Hi
When doing overlapped I/O is there a way to tell if the I/O had completed on
the subsequent reads
I check to see if the first fullword has been populated by the BDW
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This message and any attachments are intended only
Hi
When doing overlapped I/O is there a way to tell if the I/O had completed on
the subsequent reads
I check to see if the first fullword has been populated by the BDW
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