On Sat, 20 Jun 2020 18:09:35 -0500, Walt Farrell wrote: > >Time Of Check To Time Of Use. As you're making the check, a security >administrator might be changing the rules. Your program might end up getting a >false positive or false negative. > ... >It is much simpler, and safer, and in general more robust, to simply issue the >OPEN in the proper program environment and let the system say Yes or No. > As strongly as I agree with that, a programmer might have a sincere wish to avoid the side effects of a prior operation. Suppose a job successfully allocates GDG(+1) then access to another data set fails. The job does nothing useful but the generation is incremented.
That programmer wishes, ideally, that the initiator could verify access permissions for all resources mentioned in JCL in the same atomic operation in which it obtains ENQs. But it's not realistic to wish for Logical Unit of Work encapsulation of batch jobs. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
