[Python-Dev] Signals, threads, blocking C functions

["Martin v. Löwis"]

Nick Maclaren schrieb:
>> (coment by Arjan van de Ven):
>> | afaik the kernel only sends signals to threads that don't have them blocked.
>> | If python doesn't want anyone but the main thread to get signals, it
>> should just
>> | block signals on all but the main thread and then by nature, all
>> signals will go
>> | to the main thread....
> 
> Well, THAT'S wrong, I am afraid!  Things ain't that simple :-(
> 
> Yes, POSIX implies that things work that way, but there are so many
> get-out clauses and problems with trying to implement that specification
> that such behaviour can't be relied on.

Can you please give one example for each (one get-out clause, and
one problem with trying to implement that).

I fail to see why it isn't desirable to make all signals occur
in the main thread, on systems where this is possible.

Regards,
Martin