Re: Bug in signal handler

On Thu, May 11, 2006 at 08:24:02AM -0400, Douglas McNaught wrote:
> Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
>
> > Running unsafe functions within a signal handler is not unsafe per-se.
> > It's only unsafe if the main program could also be running unsafe
> > functions.
>
> I don't disagree with your reasoning, but does POSIX actually say
> this?

On my machine, signal(2) has the following:

The routine handler must be very careful, since processing
elsewhere was interrupted at some arbitrary point. POSIX has the
concept of "safe function". If a signal interrupts an unsafe
function, and handler calls an unsafe function, then the
behavior is undefined. Safe functions are listed explicitly in
the various standards. The POSIX 1003.1-2003 list is

<long list including select(), signal() and sigaction()>

I havn't read POSIX myself though...

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.