[Info-vax] Cobol: Faster flushing of buffer to sequential file

[VAXman- at SendSpamHere.ORG]

In article <941ea11d-36c0-4110-9d8f-6d3b2d6fc323 at x1g2000yqb.googlegroups.com>, Hein RMS van den Heuvel <heinvandenheuvel at gmail.com> writes:
>On Feb 4, 9:31=A0pm, "Richard Maher" <maher... at hotspamnotmail.com>
>wrote:
>> "George Cornelius" <cornel... at eisner.decus.org> wrote in message
>
>> > GFC_EISNER> conv/share my_file.dat his_file.lis /stat
>:
>> > Total Records Processed: =A0 =A0 =A0 =A0 =A0 0 =A0 =A0Buffered I/O Coun=
>t: =A0 =A0 =A0 =A0 =A0 11
>:
>
>I was wrong about the CONVERT/SHARE.
>I forgot that CONVERT uses UPI sharing
>In an attempt to optimize (reduce locks) it overshoots its 'raison
>d'etre' : get the data.
>
>
>> > GFC_EISNER> type his_file.lis
>>
>> > -----------------------------------------------------------------------=
>---- --
>:
>> The consensus and all supporting evidence is that either a $flush or clos=
>e
>> of the file is required to force the data to be written thru to disk.
>
>Practically YES: Consensus. And Flush needed.
>Technically NO: The data IS written tot the disk.
>It's just that mere mortals can not see it there.
>So practically it ain't there :-).
>
>Still, Technically the write IO _is_ done all the way through to the
>disk.
>And the EOF _is_ updated ... in the RMS Shared File Lock Value Block,
>just not on disk.
>
>This van be verified in many ways.
>
>1) RMS file statistics
>
>2) LD driver IO traces
>
>3) ANALYZE/SYSTEM ... SHOW PROC/RMS=3DBDBSUM ( buffer VALID, not DIRTY
>not IO in PROGRESS)
>
>My favorite method:
>
>4) $ dump/head/bloc=3Dcount=3D1/width=3D80/ALLOCATED  my_file.dat
>:
>        End of file block:                1
>        End of file byte:                 0
>:
>    Retrieval pointers
>        Count:          6        LBN:   15913410
>:
>Virtual block number 1 (00000001), 512 (0200) bytes
>
> 20202020 20202065 67617373 656D2041 A message        000000
>:
>
>> PS. I still believe RMS has some other incantation but no one here knows =
>or
>> is interested in sharing. (Or I'm just talking crap :-)
>
>That would be to use the official method to read the file.
>
>5) The reader opens the file with full sharing.
>
>Below the signature a dinky example program to do just that which I
>happened to have posted earlier this week in:
>http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=3D146=
>6976
>
>Clear as mud?
>Hein
>

Is the quoted-pukeable crap due to posting through Google Groups?
Or, due to what you use to post there?




>$ type MAILBOX_TO_FILE.MAR
>        .psect  data, wrt, noexe
>buf:    .blkb   32*1024
>infab:  $FAB fnm=3Dmailbox_input,dnm=3Dsys$login:.dat,fac=3Dget,shr=3Dput
-----------------^^^-----------------^^^------------------^^^-------^^^
>inrab:  $RAB fab=3Dinfab,usz=3D32000,ubf=3Dbuf
-----------------^^^---------^^^---------^^^
>outfab: $FAB fnm=3Dlog_output,dnm=3Dsys
-----------------^^^--------------^^^
>$login:.log,fac=3Dput,shr=3Dput,fop=3Ddfw,rat=3Dcr
-----------------^^^------^^^-------^^^-------^^^
>outrab: $RAB fab=3Doutfab,rbf=3Dbuf
-----------------^^^----------^^^
>
>        .psect  code, nowrt, exe
>        .entry  start,0
>        $OPEN fab=3Dinfab
------------------^^^
>        blbc    r0,error
>        $CREATE fab=3Doutfab
--------------------^^^
>        blbc    r0,error
>        $CONNECT rab=3Dinrab
---------------------^^^
>        blbc    r0,error
>        $CONNECT rab=3Doutrab
---------------------^^^

Why not just $CREATE and CIF?

>        blbc    r0,error
>loop:
>        $GET    rab=3Dinrab
--------------------^^^
>        blbc    r0,end
>        movw    inrab+rab$w_rsz, outrab+rab$w_rsz
>        $PUT    rab=3Doutrab
--------------------^^^
>        blbc    r0,error
>        brw     loop
>end:
>        cmpl    r0,#RMS$_EOF
>        beql    succes
>error:  ret
>succes:
>        movl    #1, r0
>        ret
>        .end    start
>$ mac MAILBOX_TO_FILE.MAR
>$ lin MAILBOX_TO_FILE
>$ run MAILBOX_TO_FILE
>A message
>$
-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

All your spirit rack abuses, come to haunt you back by day.
All your Byzantine excuses, given time, given you away.