Re: Cancel/Kill backend functions

>> >> Okay, here is an updated patch. now uses IsBackendPid(), which is
>> >> closely modeled (read cut-and-pasted) from
>> >> TransactionIdIsInProgress().
>
>I wonder what can happen if a backend passes the
>IsBackendPid() test and
>terminates just before the kill() signal?  It should be pretty unlikely
>but you could signal the wrong process ... shouldn't the SInvalLock be
>held throughout the whole operation?

You'd actually need to get a pid *reuse* during that short time.
Otherwise, you're just kill():ing a nonexistant process, which should be
no problem.

This is the same as issuing a "kill -INT <pid>" from the shell after
doing ps(1), which is basically what this function tries to emulate.
Should be no more dangerous than that.

Bottom line -  while maybe slightly more correcet, not sure it's
necessary.

//Magnus