* Daniel Colascione: > But doesn't the CSIGNAL approach still require that libraries somehow > coordinate which non-SIGCHLD signal they use? (Signal coordination a > separate problem, unfortunately.) There's already an allocation mechanism for realtime signals in glibc, via __libc_allocate_rtsig. I don't know what it is about: It's clearly intended as an external interface, yet there isn't a declaration in any installed header file. ALSA has some optional code to use it, but I don't think distributions compile ALSA in that way; it always uses SIGIO. Thanks, Florian