On Fri, 18 Jun 2021 12:02:18 -0600, "Theo de Raadt" wrote: > But I dislike this text since it doesn't speak to the underlying > mechanism. > > The > .Fn alarm > function configures the process > .Va ITIMER_REAL > interval timer with > .Xr setitimer 2 > to deliver a > .Va SIGALRM > signal in the future. > > (This also hints that parallel use of the underlying mechanism, > ITIMER_REAL, could break expectations.)
This is an implementation detail that is not reflected by the standard. Historically alarm() was a system call and there are still OSes where that is the case. On the other hand, it is good to document that on OpenBSD trying to use both alarm() and ITIMER_REAL would interact in surprising ways. To me, this seems like information that belongs in a CAVEAT section. - todd
