> Thanks John, > > I'm dealing with tape drives. So I don't want somebody to accidentally try > to write to the drive they're reading from. :-) though hopefully they'd > mount the input tape as input/noring and a write ccw would choke and I'd > exit on the unit check. > > Prior to pipcommt 0, I'd like to make sure the device isn't in use > somewhere else in the pipeline. > > I guess I was envisioning a simple macro like > pipregdv , R1 has the device number to "register" > jnz alreadyInUse > > Where pipregdv updates a table with the device number and stage number > requesting it. If it's already in the table, return the stage number in r1 > and set a non-zero cc. > > But, if there's some sort of control/parm block I can build and call an > existing function, that's all good too. :-) >
What's missing in the tape support in CMS Pipelines? I have done quite some plumbing with tapes in the ancient past... I kept quiet because I didn't realize the pipeline vector allows user-written stages to use it. And by using the same mechanism you also guard yourself against a rogue 'tape' stage going after the device. Your stage would also need to something to handle I/O interrupts, and post an ECB, isn't it? Yes, it's pretty much what you envisioned, be it that some of the error handling is basically offloaded to IOSNQ rather than letting the stage pick it up. Rob --- Rob van der Heij z/VM Development, CMS PipelinesTenzij hierboven anders aangegeven: / Unless stated otherwise above: IBM Nederland B.V. Gevestigd te Amsterdam Inschrijving Handelsregister Amsterdam Nr. 33054214
