Record locking

[Kenneth Brody]

GCC Consulting wrote:
[...]
> 10 Get_num if:
>       then: rn(8,.0)="1"
> 11        if:
>        then: lookup emm = em_mast  r=rn    -np
> 12        if:    not emm
>        then: ERRORBOX "Master File Not Found";EXIT
> 13        if:
>          then: po_num=emm(10);GOSUB chk_num                     (chk_num does a
> lookup to the current file to insure that
> 14        if:                                                           (this #
> hasn't been used and some other checks
[...]

What does chk_num do, exactly?  Does it ever wait for user input?  (If
so, you have to remember that the control record is locked until chk_num
returns.)  What does it do should it find a duplicate?  (And how could a
duplicate number be generated, if it is always generated via a protected
lookup to the control file?)

-- 

+---------+----------------------------------+-----------------------------+
| Kenneth |     kenbrody at spamcop.net      | "The opinions expressed     |
|    J.   |    http://www.hvcomputer.com     |  herein are not necessarily |
|  Brody  |      http://www.fptech.com       |  those of fP Technologies." |
+---------+----------------------------------+-----------------------------+