Re: File locking / field locking

[Alan Shore <AlanShore@xxxxxxxx>]

Hi Doug
The lock is on the record you have just READ and NOT the record you want to
add.
It is still feasible for another process to read the same files as
input/add, read the same record that you have just locked, and add the same
record you want to add, thus creating duplicates.
The best way around this is to make the file unique on that field and by
using monitor, to capture the error of attempting to create a duplicate
record



Alan Shore
Programmer/Analyst, Direct Response
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"If you're going through Hell, keep going" - Winston Churchill

rpg400-l-bounces@xxxxxxxxxxxx wrote on 10/17/2008 09:56:39 AM:

>    I have two files SourcePF is my physical file and SourceLF is a
logical
>    built over that PF.  Both are included in the program as update files
with
>    add.
>
>    In a subroutine the program sets a HIVAL on the logical and then does
a
>    readp in order to get the highest shipping number.  At this point I
>    believe this field is locked and no other process can access read that
>    record.  it then increrments the count and writes it to a variable.
The
>    other variables are setup and then the program finally writes a new
record
>    to the Physical file, which at that point the lock is released
correct?
>    I am just checking every possible place for this thing to create
duplicate
>    records (I did not write the code, just plugging the hole).....and
making
>    sure that neither program can dup up the same number.
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