Hi Charles
Just a thought.  When you ED VOC Dummy, you are creating a new record, where 
you are locking the Key to not be used by another process rather than locking 
the record.   I am not sure where the locks are on the file system, but I 
wonder if Dummy already existed before you edited, whether this would be 
different.  Also it would be worth test the difference of using READL and READU.
David

-----Original Message-----
From: u2-users-boun...@listserver.u2ug.org 
[mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Charles Stevenson
Sent: Sunday, 30 October 2011 10:22 AM
To: Charles Stevenson
Cc: U2 Users List
Subject: Re: [U2] [UV] LIST.READU EVERY's "waiters" when there are writes w/o 
explicit readu.

I hate to bring it up after 50+ responses over 4 days,  but . . .

Did anyone ever actually run my little test?

On something other than my UV10.2/Win?  Unix?  Before UV10.2?

Knowing that would help me assess the size & age of our problem.

I still think that in times past, a waiterfor a lockvia WRITE or DELETEwould 
show up at the 3rd section of LIST.READU EVERY, even as the typical READU (or 
FILELOCK, RECORDLOCKU) does.


The original test was request was this:


On 10/24/2011 4:11 PM, Charles Stevenson wrote:
> UV 10.2.10 on Windows is behaving differently from what I recall.
> Are my expectations out of line?
>
> Suppose Session A holds a readu lock; and Session B attempts a WRITE 
> to same record withOUT!!! 1st explicitly getting the readu lock.
> Session B waits for Session A to release the lock before writing the 
> record.
>
> While Session B is waiting,  does it show up as a "waiter" in 
> LIST.READU EVERY?
> I expected so,  but it doesn't.
>
>
> Session A                       Session B
> _____________________________   ___________________
> 1A. ED VOC DUMMY
>    (this sets the readu lock.)
>
> 2A. (stay in editor)            2B. run this:
>                                     01:    OPEN 'VOC' TO F ELSE STOP
>                                     02: ***READU REC FROM F, 'DUMMY' 
> ELSE NULL
>                                     03:    WRITE '' TO F, 'DUMMY'
>
> 3A. Within ED:
>     XEQ LIST.READU EVERY
>
>
> If I UN-comment line 2, LIST.READU EVERY shows something like this:
>
>     Active Read Waiters:      Owner   Waiter
>     Device....  Inode....     Userno  Userno
>     746117947    232860913      6116    3396
>
>
> But when I comment out line 2, LIST.READU is silent.
> I have not yet explored what the deadlock daemon does.
>
> TIA,
> cds
>
>
> P.S. Yes, yes, "Bad Form", "Legacy Software", 20 min wait is 
> configurable, . . . we can talk later.

"Later" is already past.  I'm not talking about that P.S. again!
thank-you,
cds
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