Oh I agree!  I was just thinking round-robin that if we're going to talk
about adding a LOCKED clause to the WRITE statement, matching the
structure of READU, then we ought to have a WRITEU, too.  Didn't say I
liked the idea....

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Mecki
Foerthmann
Sent: Monday, October 24, 2011 3:30 PM
To: [email protected]
Subject: Re: [U2] [UV] LIST.READU EVERY's "waiters" when there are
writes w/o explicit readu.

Now why would anybody want to use a WRITE without a READU?
I can possibly understand that somebody would want to do it with a 
WRITEV (i.e writing a flag on a record) but WRITE?
And WRITE totally ignoring locking would be outright stupid.

On 24/10/2011 22:28, Woodward, Bob wrote:
> I would think that because you are not trying to obtain the lock in a
> WRITE statement, it would not be classified as a waiter.  True, it's
> waiting because of the lock but by not trying to obtain the lock, it's
> only waiting for the blockage to clear.  If it were to be classified
as
> a waiter then I would expect to see a LOCKED clause on the WRITE
> statement like there is on the READU.  For that matter, I'd expect to
> see a WRITEU command as well and the standard WRITE to completely
ignore
> locking.
>
> Just my guess, though.
>
> BobW
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Charles
> Stevenson
> Sent: Monday, October 24, 2011 2:12 PM
> To: U2 Users List
> Subject: [U2] [UV] LIST.READU EVERY's "waiters" when there are writes
> w/o explicit readu.
>
> 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
STOPM
> 'nope'
>                                       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.
>
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