sleep

fn sleep(userdata: ?*anyopaque, timeout: Io.Timeout) Io.Cancelable!void {
    const ev: *Evented = @ptrCast(@alignCast(userdata));
    const queue = c.dispatch.queue_create_with_target(
        "org.ziglang.std.Io.Dispatch.sleep",
        .SERIAL(),
        ev.queue,
    ) orelse {
        log.warn("failed to create serial queue for sleep", .{});
        return ev.yield(.{ .after = ev.timeFromTimeout(timeout) });
    };
    defer queue.as_object().release();
    const timer = c.dispatch.source_create(.TIMER, 0, .none, queue) orelse {
        log.warn("failed to create timer for sleep", .{});
        return ev.yield(.{ .after = ev.timeFromTimeout(timeout) });
    };
    var waiter: SleepWaiter = .{
        .cancelable = .{ .queue = queue, .cancel = &SleepWaiter.canceled },
        .timer = timer,
    };
    timer.as_object().set_context(&waiter);
    timer.set_event_handler(&SleepWaiter.timedOut);
    timer.set_cancel_handler(&SleepWaiter.wake);
    timer.set_timer(ev.timeFromTimeout(timeout), c.dispatch.TIME_FOREVER, ev.leeway);
    ev.yield(.{ .sleep_wait = &waiter });
    timer.as_object().release();
    try waiter.cancelable.acknowledge(waiter.sleeper.fiber);
}