Re: [RFC] Toward Shareable POSIX Signals

[Florian Weimer <fweimer at redhat dot com>]

On 03/09/2018 05:41 PM, Rich Felker wrote:
> "Just use glib" is of course fundamentally unacceptable. But the
> obvious solution is "just use threads" and I don't see why that's not
> acceptable. The cost of a thread is miniscule compared to the cost of
> a child process, and threads performing synchronous waitpid can
> convert the result into whatever type of notification (poll wakeup,
> cond var, synchronous handling, etc.) you like. This is clearly the
> best approach for any application that's not creating at least
> tens/hundreds of child processes per second; when people refuse to use
> it in such a situation, it's because of irrational aversion to threads
> and nothing else.

But this only works for asynchronous signals.  It's reasonable for an 
application to want to catch synchronous signals (SIGBUS when dealing 
with file mappings, SIGFPE for arithmetic), and there is currently no 
thread-safe or library-safe way at all to do that.

Thanks,
Florian