Re: [HACKERS] Should we standardize on a type for signal handler flags?

On Tue, Jun 6, 2017 at 1:33 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I think that's a pretty good argument, really.  If there exists a
>> platform where only sig_atomic_t is safe to read from a signal
>> handler, then we already don't work on that platform.  Even saving and
>> restoring errno isn't safe in that case.
>
> That's an argument from false premises.  The question here is what types
> are safe for an interrupt handler to *change*, not what can it read.

OK, but we certainly have code in signal handlers that does:

int save_errno = errno;
/* stuff */
errno = save_errno;

If that's not a signal handler changing an int, color me confused.

-- 
Robert Haas
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