Re: amcheck/verify_heapam doesn't check for interrupts

> On Aug 26, 2021, at 2:38 PM, Peter Geoghegan <pg@bowt.ie> wrote:
> 
> It looks like we neglect to call CHECK_FOR_INTERRUPTS() anywhere
> inside verify_heapam.c. Is there any reason for this?

Not any good one that I can see.

> Can't we just
> put a CHECK_FOR_INTERRUPTS() at the top of the outermost loop, inside
> verify_heapam()?

I expect we could.

> Not sure if pg_amcheck itself is a factor here too -- didn't get that far.

That runs an event loop in the client over multiple checks (heap and/or btree) running in backends, just as reindexdb and vacuumdb do over parallel reindexes and vacuums running in backends.  It should be just as safe to ctrl-c out of pg_amcheck as out of those two.  They all three use fe_utils/cancel.h's setup_cancel_handler(), so I would expect modifying verify_heapam would be enough.

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Mark Dilger
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