想问下在协程内创建Timer和在Timer内创建协程的情况对比？

$timer_id = Timer::add(2.5, function()  {
    Coroutine::create(function () {
        $this->coroutine()
    }
});

Coroutine::create(function () {
    Timer::add(2.5, function()  {
        echo 111；
    }
}

$timer_id = Timer::add(2.5, function()  {
    $this->coroutine()
});