Am Dienstag, den 09.05.2006, 16:39 -0400 schrieb Stefan Seefeld:
Aristid Breitkreuz wrote:
Am Dienstag, den 09.05.2006, 19:22 +0000 schrieb Ryan Gallagher:
Gennadiy Rozental wrote:
SIGNAL catching is optional and doesn't constitute portabiltiy issues per se, whether to use it's up to you. Out of curiousity, what is a good (portable?) way of dealing with signals in C++? C signal handling seems to force globals on you, which is a pain especially when signal handling is a late requirement.
You might want to use a UNIX pipe for that (by calling pipe(2)). Just write(2) into a pipe (less than PIPE_BUF bytes) and select(2) on it. This is thread-safe and signal-safe and everything. Just not too speedy.
I think semaphores are a widespread way to communicate from signal handlers back to a running program. They are reentrant, and their use involves less system calls than pipes, I believe.
The huge advantage of pipes is that with select, you can poll multiple event sources at once. Multiple sem_wait must be placed into multiple threads, which is probably more overkill for those rare signals than the selfpipe-trick (as they call it).
I don't think thinking of portable signal handling mechanisms is sensible, as signals themselves are (mostly) non-portable.
In itself, such a mechanism is not too sensible.
Regards, Stefan _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost