const EventFd: type = switch (builtin.os.tag) {
.macos, .ios, .tvos, .watchos, .freebsd, .netbsd, .dragonfly, .openbsd => KEventFd,
.linux => struct {
base: ResumeNode,
epoll_op: u32,
eventfd: i32,
},
.windows => struct {
base: ResumeNode,
completion_key: usize,
},
else => struct {},
};