On Mon, Sep 28, 2015 at 3:54 PM, Paul Gilmartin < 0000000433f07816-dmarc-requ...@listserv.ua.edu> wrote:
> On Mon, 28 Sep 2015 18:35:07 +0000, Dave Barry wrote: > > >I seem to recall a recent enhancement to z/FTP dynamic allocation that > reports contention and retries some number of times at user-defined > intervals. TSO ALLOC and IDCAMS might take that as an example for future > development. > > > So instead of deadlocks you can have livelocks? You can code that loop > yourself. > Perhaps what is needed is a new option on the ENQ. Normally, when you do an ALLOCATE and the DSN is unavailable, you get an immediate failure. OTOH, there is a parameter in the SVC 99 control block which allows an APF authorized program to WAIT "forever". Which basically leads to the thought that it would be nice to have an ENQ option with a "timeout" value. I.e. give me this and, if not available, wait for at most ???? <time intervals> in the hopes it will soon will be available. This could be emulated by having the ENQ logic in a subtask. The main task invokes this subtask, the subtask does the ENQ followed by a POST of an ECB. The main task then sets up a STIMER for the "max wait" interval. It then waits on one of two ECBs to be posted. The ENQ subtask ECB or the STIMER expiration ECB. If the STIMER expires, just force DETACH the subtask to terminate it. > > -- gil > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- Schrodinger's backup: The condition of any backup is unknown until a restore is attempted. Yoda of Borg, we are. Futile, resistance is, yes. Assimilated, you will be. He's about as useful as a wax frying pan. 10 to the 12th power microphones = 1 Megaphone Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
