Building a watchdog
I need to do a watchdog for a process. That process (let's call it p2) is also coded by me.
However, since this is a assignment for school, I'm supposed to figure a way to see if p2 is still alive without p2 doing anything at all.
The way i'm thinking this means no semaphores and no pipes.
Anyone has any idea of what mechanism can be used? I've been thinking about this for days but can't come up with anything.
Thanks in advance.
This seems operating system-specific. Weren't you just asking about how to find whether processes are active? Why wouldn't that work here too?
I agree with tabstop since this question seems OS specific.
Do you know if the watchdog runs in user or supervisor mode?
I was about to reply on that thread but then i thought it would be off topic because the solution might be something else entirely but if you think it's more appropriate I can move back there.
Well it belongs to an OS board, for sure; and since it would appear to be the exact same question then there's no problem with that thread.
Ok my bad, I'll reply there then.
One possibility is to have the watched process write its pid to a file in a known location and file name. The watchdog could periodically open the file, read the pid, and check that the process with that pid is still running.
I would guess that doesn't fit "without p2 doing anything at all", though.Originally Posted by rags_to_riches
Doh! Reading fail.
The answer comes right down to the definition of "p2 is still alive".
Pin down that definition and you should have your answer.
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