Post expects either the post bit, and does nothing, or an RB address in
which case it decrements the wait count and if the count reaches zero, the
task is made dispatchable. 

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf
Of Paul Gilmartin
Sent: Wednesday, January 23, 2008 9:31 AM
To: [email protected]
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 how many people on
>IBM-MAIN are still exhibiting confusion regarding its use -- even about
>something as fundamental as how/when to clear the ECB! This observation
>seems to support Chris Craddock's assertion that, even after more than
>40 years, the documentation is still quite lacking.
>
I suppose the assertion can be further supported by failure
to exhibit such documentation.

Until this thread, I had envisioned no use of the ECB except by
WAIT and POST; thus no need to clear it other than (immediately)
before WAIT.  You and Peter R. have demonstrated otherwise.

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.)

-- gil

----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html

----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html

Reply via email to