William Kucharski wrote: > > This works in actual implementation but beware of the side effect that > now > any binary compiled prior to your change that does anything with > _SIGRTMIN > will now be doing it with SIGINFO. That could lead to some interesting > compatibility issues down the road. Applications should not use _SIGRT*, otherwise they get what they ask for :-) It looks like SIGRT* (no leading _) have been defined as sysconf(2) calls since 1993, I assume with the intent of making it possible to add signals in a backward compatible way. This has happened once already, in 1999, when SIGJVM1 and SIGJVM2 were added, and _SIGRTMIN was bumped according to the instruction in the comment in sys/iso/signal_iso.h.
Like the signal.h(3HEAD) manpage says: SIGRTMIN * Exit First real time signal (SIGRTMIN+1) * Exit Second real time signal ... (SIGRTMAX-1) * Exit Second-to-last real time signal SIGRTMAX * Exit Last real time signal The symbols SIGRTMIN through SIGRTMAX are evaluated dynami- cally to permit future configurability. - Frank