In [EMAIL PROTECTED],
on 01/22/2008
at 04:12 PM, Van Dalsen, Herbie [EMAIL PROTECTED] said:
I should not ask the question, but do they exist or is it a 'virus'
inside IBM-MAIN?
Google for Wheeler Scheduler. Yes, I find the long URL lists and the
repetitive OT paragraphs to be frustrating, but
Do the contents of the ECB other than the WAIT and POST bits
matter to WAIT?
no. Although, when the WAIT bit is on, they do matter to POST.
IOW, instead of XC ECB,ECB (or CS) would it suffice
to do as little as MVI ECB,x'3F'
yes
Even though task synchronization and resource serialization are
On Thu, 24 Jan 2008 07:26:55 -0500, Peter Relson
[EMAIL PROTECTED] wrote:
...
I disagree. Especially when the thread gets into pointing out the
deficiencies of wait/post as a serialization mechanism. Not surprising.
It
really isn't one.
...
What? Not for serialization? And not for queueing?
] On Behalf
Of Edward Jaffe
Sent: Wednesday, January 23, 2008 12:19 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
David Logan wrote:
No, I didn't think you were arguing that WAIT/POST didn't work, and you do
definitely have some valid points. It would be *quite
In [EMAIL PROTECTED], on
01/22/2008
at 01:22 PM, Craddock, Chris [EMAIL PROTECTED] said:
Nope. It falls prey to the TOCTTOU problem. Moreover, the normal
content of the ECB after a post is X'4000',
That's a legitimate value, but I doubt that it's normal.
BTW, why is everybody boycotting
--snip-
If you really do have multiple units of work that need to coordinate their
processing then you need; not only a way to poke the other guy in the arm or
wait for a poke in the arm, but you also need something that doesn't allow you
to miss a
David Logan wrote:
Even though task synchronization and resource serialization are technically
different, for the purposes of this discussion, they are essentially the
same thing.
Lock, ENQ, latch, etc.serialize update access to any resource being
accessed concurrently by two or more
: Wednesday, January 23, 2008 9:31 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
On Wed, 23 Jan 2008 07:53:42 -0800, Edward Jaffe wrote:
I agree that WAIT/POST -- a service that's been around since OS/360 --
seems simple enough on the surface. But, look
Nope. It falls prey to the TOCTTOU problem. Moreover, the normal
content of the ECB after a post is X'4000',
That's a legitimate value, but I doubt that it's normal.
The most common post code (which I tend to think of as being normal)
is zero, i.e.
POST ecbaddr,0
And for that value
BTW, do the contents of the ECB other than the WAIT and POST bits
matter to WAIT? IOW, instead of XC ECB,ECB (or CS) would it suffice
to do as little as MVI ECB,x'3F', or would it disrupt the fabric
of the universe? (Don't ask why; mere scientific interest.)
No the universe will be fine.
Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Paul Gilmartin
Sent: Wednesday, January 23, 2008 11:31 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
On Wed, 23 Jan 2008 07:53:42 -0800, Edward Jaffe wrote:
I agree that WAIT/POST -- a service
On Wed, 23 Jan 2008 07:53:42 -0800, Edward Jaffe wrote:
I agree that WAIT/POST -- a service that's been around since OS/360 --
seems simple enough on the surface. But, look how many people on
IBM-MAIN are still exhibiting confusion regarding its use -- even about
something as fundamental as
In [EMAIL PROTECTED], on
01/22/2008
at 11:42 PM, Craddock, Chris [EMAIL PROTECTED] said:
You're comparing apples and fish. Locking has nothing to do with it.
Outside of the sup-state-only suspend/resume function, wait/post was the
only primitive available for synchronizing separate units of
Craddock, Chris wrote:
BTW, why is everybody boycotting EVENTS?
It's just a cover function for wait/post. It is more efficient than WAIT
in the case where you have lots of potential events to be waited on, but
the units are still ECBs so it has most of the same pitfalls.
I never knew
On Wed, 23 Jan 2008 12:50:54 -0500, Craddock, Chris [EMAIL PROTECTED]
wrote:
BTW, do the contents of the ECB other than the WAIT and POST bits
matter to WAIT? IOW, instead of XC ECB,ECB (or CS) would it suffice
to do as little as MVI ECB,x'3F', or would it disrupt the fabric
of the universe?
On Wed, 23 Jan 2008 00:10:57 -0500, Craddock, Chris
[EMAIL PROTECTED] wrote:
...
Yes because leaving aside the quirks with the current wait/post
mechanism, the wait/post logic is at best, half of the problem in any
true multitasking code. ...
Sorry to be falling way behind in my pedantary.
In [EMAIL PROTECTED], on
01/23/2008
at 12:40 PM, Craddock, Chris [EMAIL PROTECTED] said:
The most common post code (which I tend to think of as being normal) is
zero, i.e.
POST ecbaddr,0
We must not be looking at the same code; most of what I've seen either has
an EXCP bias and posts a code
PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
In [EMAIL PROTECTED], on
01/23/2008
at 12:40 PM, Craddock, Chris [EMAIL PROTECTED] said:
The most common post code (which I tend to think of as being normal)
is
zero, i.e.
POST ecbaddr,0
We must
januari 2008 06:56
Till: IBM-MAIN@BAMA.UA.EDU
Ämne: Re: How does ATTACH pass address of ECB to child?
Warning: kind of a long-ish reply coming up;
What exactly is wrong with the ECB/WAIT/POST mechanism? I
think it has
always worked great. It's got some pretty difficult limitations in
cross
On Tue, 22 Jan 2008 01:31:45 -0500, Robert A. Rosenberg wrote:
At 1:38 PM -0600 on 1/21/08, Paul Gilmartin wrote about Re: How does
ATTACH pass address of ECB to child?:
When the mother needs the daughter's assistance, it WAITs on the
second ECB, clears it, and POSTS the first.
ONLY
In [EMAIL PROTECTED], on 01/21/2008
at 11:10 AM, Paul Gilmartin [EMAIL PROTECTED] said:
I have believed, and other updates to this thread appear to concur, that
WAIT/POST are older than CS. At some time, then, WAIT/POST code must
have used some other locking mechanism.
That much is true.
You can be certain that POST will always support the CS quick-post protocol
and the LOCAL LOCK.
I'm curious, as nothing pops to mind: has there been any case where the
serialization of a documented programming interface has changed? Maybe I
should limit my question to z/OS BCP where compatibility
On Tue, 22 Jan 2008 08:00:52 -0500, Peter Relson wrote:
You can be certain that POST will always support the CS quick-post protocol
and the LOCAL LOCK.
OK. I'll be confident. But why is this not documented in the
Assembler Services Reference? Interestingly, there, I see for POST:
#
://www.garlic.com/~lynn/2008b.html#50 How does ATTACH pass address of ECB
to child?
as stated in the above post ... the principles of operation wording is
from over 35yrs ago ... charlie had invented the compareswap
instruction at the science center while doing fine-grain lock for cp67
... and the pok favorite
:
http://www.garlic.com/~lynn/2008b.html#50 How does ATTACH pass address of
ECB to child?
as stated in the above post ... the principles of operation wording is
from over 35yrs ago ... charlie had invented the compareswap
instruction at the science center while doing fine-grain lock for cp67
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
Sorry for the slightly off-topic question, but how come this persons posts are
always so complicated to work through with all of the pieces and URL links? Is
it the function of how they are posting (i.e. perhaps online
David Logan wrote:
Sorry for the slightly off-topic question, but how come this persons posts
are always so complicated to work through with all of the pieces and URL
links? Is it the function of how they are posting (i.e. perhaps online with
certain options), or is this a manual effort?
ATTACH pass address of ECB
to child?
some of it overlaps
http://www.garlic.com/~lynn/2008b.html#27 Re-hosting IMB-MAIN
and some of it explained in these recent postings
http://www.garlic.com/~lynn/2008b.html#57
http://www.garlic.com/~lynn/2008b.html#64
starting in the late 70s, i had been doing
PROTECTED] On
Behalf Of Edward Jaffe
Sent: Tuesday, January 22, 2008 9:08 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Wheeler Postings (Was: How does ATTACH pass address of ECB to
child?)
David Logan wrote:
Sorry for the slightly off-topic question, but how come this persons
posts
are always so complicated
Postings (Was: How does ATTACH pass address of ECB
to child?)
Edward,
It may be better asked off list, but I have been wondering the same
thing for a long time as well. Frankly, I'm glad the question was asked.
Can anyone offer a definitive answer? Or just speculation?
Chuck
-Original Message
are slightly garbled:
http://www.ibmsystemsmag.com/mainframe/marchapril05/stoprun/10020p1.aspx
re:
http://www.garlic.com/~lynn/2008b.html#63 How does ATTACH pass address of ECB
to child?
http://www.garlic.com/~lynn/2008b.html#65 How does ATTACH pass address of ECB
to child?
i.e. the ibm systems mag
Lynn has answered that question a while ago. Check the archives. (His or
ibm-main's)
--
Tom Schmidt
--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET
Thanks
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Tom Schmidt
Sent: 22 Januarie 2008 04:51 nm
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: Wheeler Postings (Was: How does ATTACH pass address of ECB
to child?)
Lynn has answered that question
In [EMAIL PROTECTED],
on 01/22/2008
at 10:00 AM, Rob Scott [EMAIL PROTECTED] said:
but then again that could describe quite a few board members :-)
There are none; this is not a boars.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see
Paul Gilmartin wrote:
(I did say clear the ECB before POSTing the other task, didn't I?)
That's should, not must. And why not? It can't really matter,
because even if the code is the minimal:
WAIT
L R1,ECBPreserve condition code
XCECB,ECB
One little glitch remains. The mother needs to know when the daugnter
is ready to accept more work. Either of the following works:
o The daughter can simply clear the ECB to zeroes and the mother
can use this as an indication that the daughter is ready to be
POSTed. But in some
On Tue, 22 Jan 2008 08:00:52 -0500, Peter Relson [EMAIL PROTECTED] wrote:
You can be certain that POST will always support the CS quick-post protocol
and the LOCAL LOCK.
I've never understood why, after all these years, IBM hasn't put the
quick-post code right into the POST macro. Of course
(I did say clear the ECB before POSTing the other task, didn't I?)
That's should, not must. And why not? It can't really matter,
because even if the code is the minimal:
WAIT
L R1,ECBPreserve condition code
XCECB,ECB Clear ECB
Craddock, Chris wrote:
More typically you also need to develop a robust queuing mechanism for
passing work requests and responses between requesters and servers. That
is because, if you look dispassionately at the ECB as an interface,
there is no way to avoid the potential of missing an
Here, for instance:
http://groups.google.com/group/bit.listserv.ibm-main/msg/7941aee482af5b4
8?
Jon
snip
Lynn has answered that question a while ago. Check the archives. (His
or ibm-main's)
/snip
--
For IBM-MAIN subscribe /
On Tue, 22 Jan 2008 12:37:34 -0500, Gerhard Postpischil wrote:
Paul Gilmartin wrote:
(I did say clear the ECB before POSTing the other task, didn't I?)
That's should, not must. And why not? It can't really matter,
because even if the code is the minimal:
WAIT
L
On Tue, 22 Jan 2008 10:51:29 -0800, Edward Jaffe wrote:
Craddock, Chris wrote:
More typically you also need to develop a robust queuing mechanism for
passing work requests and responses between requesters and servers. That
is because, if you look dispassionately at the ECB as an interface,
On Tue, 2008-01-22 at 13:22 -0500, Craddock, Chris wrote:
Did I mention it was a crap mechanism?
I must have missed that nuance - could you explain a little what you
mean ???
.
.
.
g,d,r
Shane ...
--
For IBM-MAIN subscribe /
Paul Gilmartin wrote:
On Tue, 22 Jan 2008 10:51:29 -0800, Edward Jaffe wrote:
Rather, to request that a service task perform some function, one should
put the request on a queue and then POST the ECB on which the service
task WAITs for work. (Note: In a design involving multiple requesters,
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Craddock, Chris
Sent: Tuesday, January 22, 2008 1:29 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
Snipped
In anything but the most trivial case
The following message is a courtesy copy of an article
that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[EMAIL PROTECTED] (Farley, Peter x23353) writes:
Granted, but the converse is also true: A posix-style semaphore or
queuing mechanism is way overkill for the
On Tue, 22 Jan 2008 11:49:34 -0800, Edward Jaffe wrote:
Rather, to request that a service task perform some function, one should
put the request on a queue and then POST the ECB on which the service
task WAITs for work. (Note: In a design involving multiple requesters,
many such requests
-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Paul Gilmartin
Sent: 23. tammikuuta 2008 1:00
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
Aha! At last I see. That answers my question to Peter R. But I
was envisioning
Paul Gilmartin wrote:
Aha! At last I see. That answers my question to Peter R. But I
was envisioning a technique in which only one task at a time updates
the queue, handing it back and forth with two ECBs. Now there's
still need to manage concurrent accesses to the queue. I suppose
CS can
On Tue, 22 Jan 2008 17:00:07 -0600, Paul Gilmartin
[EMAIL PROTECTED] wrote:
...
Whenever the queue is empty, the queue emptier WAITs. But if the
queue is storage constrained, it can fill up. What does the
queue filler do then?
...
I don't think there can be a general answer to that question.
On Wed, 23 Jan 2008 00:28:42 +0100, Lindy Mayfield wrote:
Would you mind, Paul, giving a couple of examples of real life programs
that you are thinking about?
With apologies: It's been decades since I did it; the language was
not Assembler but Pascal; it would be difficult or impossible to
find
On Tue, 22 Jan 2008 18:28:02 -0600, Patrick O'Keefe wrote:
I don't think there can be a general answer to that question. If the
queue is full the queue filler has to stop putting stuff on the queue.
That means it has to stop accepting (or generating) its input, or has
to throw that input away.
Craddock, Chris wrote:
Nope! After a normal post the compare value is going to be X'4000'
and the swap value is going to be 0. If another post intervenes and
stores another X'4000' in place of the first, then the compare is
going to succeed and you'll miss a valid post. There's no way
Whenever the queue is empty, the queue emptier WAITs. But if the
queue is storage constrained, it can fill up. What does the
queue filler do then?
There are at least two types of queues; static queues, where all of the
elements are pre-allocated/formatted by the queue owner and dynamic
Lindy Mayfield wrote:
I know personally that I couldn't get my head around this stuff unless I
imagined some sort of application and how it would work using threads.
Assume you have a start task that is designed to service
requests from VTAM terminals. With the current VTAM design, one
task
Gerhard wrote:
Craddock, Chris wrote:
Nope! After a normal post the compare value is going to be
X'4000'
and the swap value is going to be 0. If another post intervenes and
stores another X'4000' in place of the first, then the compare
is
going to succeed and you'll miss a valid
it is supposed
to do.
David Logan
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf
Of Craddock, Chris
Sent: Tuesday, January 22, 2008 7:36 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
Gerhard wrote:
Craddock
On Tue, 22 Jan 2008 21:36:02 -0500, Craddock, Chris [EMAIL PROTECTED]
wrote:
...
I've been using it a little while myself :-) and so I do agree that when
used entirely within it's most tightly constrained boundaries it
works. But as I pointed out earlier there are many unobvious traps for
the
I don't understand the reams of discussion about how to handle
multiple
threads working on a single ECB, or even a single thread spuriously
posting an ECB. It isn't what it was designed for.
Given it was the only mechanism provided, by definition it was intended
for all synchronization
On Jan 22, 2008, at 10:08 AM, Hardee, Charles H wrote:
Edward,
It may be better asked off list, but I have been wondering the same
thing for a long time as well. Frankly, I'm glad the question was
asked.
Can anyone offer a definitive answer? Or just speculation?
Chuck
:[EMAIL PROTECTED] On Behalf
Of Craddock, Chris
Sent: Tuesday, January 22, 2008 9:43 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child? (1
I don't understand the reams of discussion about how to handle
multiple
threads working on a single ECB, or even a single
Pat O'Keefe said
But I have a feeling you want something that goes beyond the intended
purpose of POST and WAIT, not just a cleaned up version of the
existing function.
Yes because leaving aside the quirks with the current wait/post
mechanism, the wait/post logic is at best, half of the
David Logan wrote:
I don't understand the reams of discussion about how to handle multiple
threads working on a single ECB, or even a single thread spuriously posting
an ECB. It isn't what it was designed for.
Ummm. Yes. It is. That how most of z/OS is put together! And, most ISV
software
David Logan wrote:
No, I didn't think you were arguing that WAIT/POST didn't work, and you do
definitely have some valid points. It would be *quite* difficult to use for
more advanced locking requirements, such as multiple tasks.
Task synchronization and locking only are tangentially related
On Jan 22, 2008, at 11:10 PM, Craddock, Chris wrote:
Pat O'Keefe said
But I have a feeling you want something that goes beyond the intended
purpose of POST and WAIT, not just a cleaned up version of the
existing function.
---SNIP Good Stuff-From Chris C---
A *LONG* time ago
On Sun, 20 Jan 2008 11:09:57 -0800, Edward Jaffe wrote:
Binyamin Dissen wrote:
In the past (370 pre PLO), CS was the only way to do this function.
While it certainly is possible for IBM to rewrite WAIT/POST to use the PLO
instruction, I certainly doubt that such a code change will occur.
-Original Message-
From: IBM Mainframe Discussion List
[mailto:[EMAIL PROTECTED] On Behalf Of Paul Gilmartin
Sent: Monday, January 21, 2008 11:11 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
On Sun, 20 Jan 2008 11:09:57 -0800, Edward
-Original Message-
From: IBM Mainframe Discussion List
[mailto:[EMAIL PROTECTED] On Behalf Of McKown, John
Sent: Monday, January 21, 2008 11:28 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
-Original Message-
From: IBM
archival MVS (3.8 or earlier) that could
execute on emulated hardware supporting CS, but for which POST
requires the actual SVC?
re:
http://www.garlic.com/~lynn/2008b.html#31 How does ATTACH pass address of ECB
to child?
http://www.garlic.com/~lynn/2008b.html#47 How does ATTACH pass address
[mailto:[EMAIL PROTECTED] On
Behalf Of David Logan
Sent: 20. tammikuuta 2008 18:55
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
The bottom line is that one task needs to be suspended until some event
occurs.
WAIT causes MVS to suspend the task until the ECB
-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Lindy Mayfield
Sent: Monday, January 21, 2008 12:34 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
The light bulb finally went off, ever so dimly. Now I think I got it.
ATTACH
I understand that during a WAIT, bits 1-31 of the ECB hold the
address of a control block. If that control block resides above
the Line, might not its address spoof the POST bit? I suppose
this is not a concern because no two tasks are allowed to WAIT
concurrently on the same ECB.
The
But, and this is what was so hard for me to get. Mother can pass
Daughter an ECB for the Daughter task to use. Daughter does some
stuff
and then WAITs. Mother goes about her business until she needs
Daughter
do so something. this is still fuzzy Mother clears the ECB and
POSTs
it freeing
-Original Message-
From: IBM Mainframe Discussion List
[mailto:[EMAIL PROTECTED] On Behalf Of Lindy Mayfield
Sent: Monday, January 21, 2008 12:34 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
[snip]
Lindy
Things like atomic
On Mon, 21 Jan 2008 13:56:37 -0500, Craddock, Chris wrote:
But, and this is what was so hard for me to get. Mother can pass
Daughter an ECB for the Daughter task to use. Daughter does some
stuff
and then WAITs. Mother goes about her business until she needs
Daughter
do so something. this
analogous to the
kernel spin-lock mentioned in previous description:
http://www.garlic.com/~lynn/2008b.html#58 How does ATTACH pass address of ECB
to child?
the transaction properties for consistently updating two different
values ... is somewhat more complicated ... than simple compareswap.
Doing
Craddock, Chris wrote:
As in horshoes? Yes. The ECB is one of the most widely used tools in
the system. As a serialization primitive it is just awful, but there's
no getting away from it now.
The ECB might not be perfect, but compared to what you have to put up with
on Unix where there are
List [mailto:[EMAIL PROTECTED] On Behalf
Of Henry Willard
Sent: Monday, January 21, 2008 4:14 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
Craddock, Chris wrote:
As in horshoes? Yes. The ECB is one of the most widely used tools in
the system
Warning: kind of a long-ish reply coming up;
What exactly is wrong with the ECB/WAIT/POST mechanism? I think it has
always worked great. It's got some pretty difficult limitations in
cross
memory mode (but it still works!), but otherwise I'm not sure where
you
get awful.
Yeah, it works FSVO
At 1:38 PM -0600 on 1/21/08, Paul Gilmartin wrote about Re: How does
ATTACH pass address of ECB to child?:
When the mother needs the daughter's assistance, it WAITs on the
second ECB, clears it, and POSTS the first.
ONLY IF the mother task has nothing else it can do while it is
waiting
Subject: Re: How does ATTACH pass address of ECB to child?
Thanks. That makes sense.
What doesn't is that Cannatello's book has a page and a half on doing
POST, with one example of how to change the ECB without using the POST
macro.
He even has the child checking the ECB to see if a WAIT had been
On Sun, 20 Jan 2008 16:00:41 +0100, Lindy Mayfield wrote:
Ok, thanks, I see now. ATTACH doesn't put it there automatically, I put
it there unless I use a parameter list, and then I would make it a part
of that list.
Now that you can find it, what use can you make of it? You shouldn't
POST it.
Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Larry Crilley
Sent: 20. tammikuuta 2008 15:54
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
Not sure if someone responded or not...
When the daughter is entered, the ECB address will be off
On Fri, 18 Jan 2008 20:38:15 -0500, Anne Lynn Wheeler wrote:
A.6.3.1 Bypass Post Routine
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/A.6.3.1?SHELF=DZ9ZBK03DT=20040504121320CASE=
from above:
The following routine allows the SVC POST as used in MVS/ESA to be
bypassed
Discussion List [mailto:[EMAIL PROTECTED] On Behalf
Of Lindy Mayfield
Sent: Sunday, January 20, 2008 9:17 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
Let me see if I am understanding it all. There really isn't a need for
the daughter task to POST because
: Re: How does ATTACH pass address of ECB to child?
On Sun, 20 Jan 2008 16:00:41 +0100, Lindy Mayfield wrote:
Ok, thanks, I see now. ATTACH doesn't put it there automatically, I
put
it there unless I use a parameter list, and then I would make it a part
of that list.
Now that you can find it, what
: Sunday, January 20, 2008 9:45 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
I was curious for what reason or when one would use the POST macro.
I've been reading this bit in the docs, but it isn't quite clear, yet.
http://publibz.boulder.ibm.com/cgi-bin
On Sun, 20 Jan 2008 10:07:07 -0600 Paul Gilmartin [EMAIL PROTECTED]
wrote:
:On Fri, 18 Jan 2008 20:38:15 -0500, Anne Lynn Wheeler wrote:
:A.6.3.1 Bypass Post Routine
:http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/A.6.3.1?SHELF=DZ9ZBK03DT=20040504121320CASE=
:from above:
.
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of David Logan
Sent: 20. tammikuuta 2008 18:30
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
I'm not sure what you are asking regarding your question about what
POST
To summarize, since all the appends I have read through have been correct,
For the ECB mentioned in
ATTACH,EP=CHILD,ECB=ECB1
WAIT ECB=ECB1
DETACH (R1)
the answer to the subject question is: You don't. The child should not be
looking at this ECB. This ECB is for use by the system when the
The following message is a courtesy copy of an article
that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[EMAIL PROTECTED] (Paul Gilmartin) writes:
This is the Principles of Operation; it is not the Assembler Services
manual. Note carefully the provided that clause.
Test and set works just fine too. They are both atomic.
David Logan
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf
Of Anne Lynn Wheeler
Sent: Sunday, January 20, 2008 11:32 AM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address
pass address of ECB
to child?
http://www.garlic.com/~lynn/2008b.html#47 How does ATTACH pass address of ECB
to child?
the issue with atomic testset was that it was a purely binary value
... locked or not locked. charlie was working on fine-grain cp67
multiprocessing locking at the science center
#31 How does ATTACH pass address of
ECB to child?
http://www.garlic.com/~lynn/2008b.html#47 How does ATTACH pass address of
ECB to child?
the issue with atomic testset was that it was a purely binary value
... locked or not locked. charlie was working on fine-grain cp67
multiprocessing locking
Binyamin Dissen wrote:
In the past (370 pre PLO), CS was the only way to do this function.
While it certainly is possible for IBM to rewrite WAIT/POST to use the PLO
instruction, I certainly doubt that such a code change will occur.
Especially since PLO and CS do not serialize each other's
/2008b.html#31 How does ATTACH pass address of ECB
to child
was about quote from the principles of operation with regard to the
example of post routine bypass:
A.6.3.1 Bypass Post Routine
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/A.6.3.1?SHELF=DZ9ZBK03DT=20040504121320CASE
20, 2008 3:50 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: How does ATTACH pass address of ECB to child?
The following message is a courtesy copy of an article
that has been posted to bit.listserv.ibm-main,alt.folklore.computers as
well.
[EMAIL PROTECTED] (David Logan) writes:
While all
does ATTACH pass address of ECB
to child?
http://www.garlic.com/~lynn/2008b.html#50 How does ATTACH pass address of ECB
to child?
aka ... the ECB is defined as testing both bits zero and one ... where
atomic testset instruction only tests bit zero.
wait semantics defines that it tests that ECB
own.
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Lindy Mayfield
Sent: Friday, January 18, 2008 5:32 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: How does ATTACH pass address of ECB to child?
I wonder if I am missing something.
Here is what I
I wonder if I am missing something.
Here is what I think: My main program does an
ATTACH,EP=CHILD,ECB=ECB1
WAIT ECB=ECB1
DETACH (R1)
The program CHILD does its thing and then when done
POST ECB1
Which IIUC causes the main program to stop waiting. How does CHILD know
the address of ECB1 in
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