Linux signal handling - notifying a condition variable

[Jim King]

On Thursday, 15 March 2018 at 17:12:24 UTC, Adam D. Ruppe wrote:
> On Thursday, 15 March 2018 at 16:51:59 UTC, Jim King wrote:
>> In going through the signal documentation it looks like the 
>> signal handler must be a "nothrow @nogc" variety.
>
> Looks like notify actually can throw an exception... the way I 
> usually do signal handlers is just set a global variable:
>
> __global bool interrupted = false;
> void sigint_handler() { interrupted = true; }
>
> then in the main loop check that periodically... idk if that'd 
> work well withthe condition variable though, I have never 
> actually used that...

Thanks for that suggestion; I was in the middle of implementing 
that.  The problem with that is that it requires a busy loop to 
detect it.  It is far better to block on condition variables than 
to have a busy loop.

I agree condition variable notify could throw if the condition 
variable is not in the correct state.  I think it would be 
possible for someone to catch this and make sure it does not 
throw, but the "@nogc" part of it seems a bit more involved.  
Condition variables (and mutexes) are supposed to be usable from 
a signal handler.