On Mon, 6 Dec 2021 at 19:10, David Boyes <dboye...@gmail.com> wrote:
> 1. Create a virtual machine SYSALERT running an application (maybe the > existing SHUTTRAP tool) that enables an external interrupt handler and > connects to *SIGNAL with a specific group id and waits for an external > interrupt other than the special ones IUCV uses. Multiple copies of the > SYSALERT machine can exist so long as one copy is still running and a > member of the group at the time of the event. > I think you're making it too hard and re-inventing things we already have. I believe we did the "signal shutdown" to mimic what the hardware does to tell the operating system to get out. Most like z/OS today already triggers SA etc to stop subsystems when applicable, just like z/VM can. And so does Linux. For CMS applications can use SHUTTRAP to do what they need to close shop. The missing piece we were discussing was a pipeline stage that can listen for the event and send a record into the pipeline to close a GATE or so to roll up the pipe. If you want, you can today already create a virtual machine that offers notifications through IUCV. So my application would connect to application AMBER in user SYSALERT, and wait for something to happen. To avoid race conditions, you probably need to provide the current status of the alert when the connection is established. But maybe something like MQ is a better approach than inventing your own. Rob