Re: Proposal for Signal Detection Refactoring

On Mon, Sep 24, 2018 at 05:23:56PM -0700, Andres Freund wrote:
> On 2018-09-25 08:57:25 +0900, Michael Paquier wrote:
>> Anyway, putting the back-patching pain aside, and just for my own
>> knowledge... Andres, would it be fine to just use one sig_atomic_t
>> field which can be set from different code paths? Say:
>> typedef enum SignalPendingType {
>> PENDING_INTERRUPT,
>> PENDING_CANCEL_QUERY,
>> PENDING_PROC_DIE,
>> PENDING_RELOAD,
>> PENDING_SESSION_TIMEOUT
>> };
>
> Well, they'd have to different bits...

Sure, I forgot to write the "foo = 1 << 0" and such ;)

>> extern volatile sig_atomic_t signalPendingFlags;
>
> Note that sig_atomic_t IIRC is only guaranteed to effectively be 8 bit
> wide - so you couldn't have that many flags.

I see. I thought that it mapped at least int, but C99 tells that it
can be as small as char. That's indeed quite limited...
--
Michael