check_c_source_compiles (
                                 "#include <time.h>
                                 int main () {
                                        struct timespec time_sp = {0, 500000000L};
                                        clock_nanosleep (CLOCK_MONOTONIC, 0, &time_sp, NULL);
                                        return 0;
                                 }"
                                 PLIBSYS_HAS_CLOCKNANOSLEEP
                                )