#ifdef _SC_OPEN_MAX - if (nfd > sysconf (_SC_OPEN_MAX)) + static int sc_open_max = -1; + + if (nfd < 0 + || (nfd > sc_open_max + && (sc_open_max != -1 + || nfd > (sc_open_max = sysconf (_SC_OPEN_MAX)))))Doesn't this make poll non-reentrant? Are there systems where assigning to an int is not atomic?
I don't think so, and gnulib's gt_TYPE_SIG_ATOMIC_T defines sig_atomic_t as int if there is none provided by the system. I can make sc_open_max a sig_atomic_t if we care about it.
Paolo
