Re: Program Interrupts (signals)
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Adrian, ? I think that would be a challenge and you would either waste lot of time polling the flag, or risk running for a long time before detecting it. I must say CMS is by design, single threaded, pretty much interrupt free, so it uses blocking CP calls for disk IO, for example. The idea was that anything ¡°multi¡± was handled by CP. Especially at the level we are at there is very clean divide between CP and CMS. CP provides a virtual 370 (VM) to each user. It manages mapping the users virtual world back to the ¡°real¡± world. Virtual devices back to real devices and stops users from trampling on each other. Handling device sharing¡ ? ¡ this means CMS is pretty simple about the same as MS DOS 1.1. No directories, no virtual memory, no shared file store, no passwords. All it sees is a console, some disks, and a reader/punch/printer. It knows nothing of any other virtual machine. So for example the MVS file IO simulation is much smaller and lighter than the MVS equivalent, but it does not have to worry about concurrent access¡ ? Dave ? ?
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From: [email protected] <[email protected]> On Behalf Of adriansutherland67
Sent: 23 April 2020 12:31
To: [email protected]
Subject: Re: [h390-vm] Program Interrupts (signals)? On Thu, Apr 23, 2020 at 11:02 AM, Dave Wade wrote: Sadly my searches indicate that catching HX needs a CMS mod. ?
Thanks Dave
Great find however.
Would this work:
Could I use the HX suppression mod to stop HX. But them within GCCLIB poll the HX flag myself (is there a flag?) and if set, exit gracefully. By the way if this works it means I can make HX do what HI does for BREXX if that makes sense.
A
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