EFD_NONBLOCK
nflags |= EFD_NONBLOCK;
if (flags & ~(EFD_CLOEXEC | EFD_NONBLOCK | EFD_SEMAPHORE)) {
if (flags & EFD_NONBLOCK) {
ATF_REQUIRE((efd = eventfd(3, EFD_SEMAPHORE | EFD_NONBLOCK)) >= 0);
ATF_REQUIRE((efd = eventfd(0, EFD_NONBLOCK)) >= 0);
ATF_REQUIRE((ctx.efd = eventfd(0, EFD_NONBLOCK)) >= 0);
eventfd(0, ~(EFD_SEMAPHORE | EFD_CLOEXEC | EFD_NONBLOCK)) == -1);
ATF_REQUIRE((efd = eventfd(1, EFD_NONBLOCK)) >= 0);
ATF_REQUIRE((efd = eventfd(1, EFD_NONBLOCK | EFD_CLOEXEC)) >= 0);