nsurlsession

Hi,

I saw that there is a perfomance degratation due to a for loop used inside the static func harmlessFunction() declared in CustomSelfAwareHelper struct.

This loop is trying to verify the type with the as? operator (that have a complexity of O(n) ) and try to unwrapp the result in order to call the awake() function.

For a medium-larger project (with likely 20k+ classes) that covers old

1. 自己内网模拟一条请求60秒超时。
2. 发现定时器YMTimeoutSource一直不响应。然后直接断点发现，是如下代码一直在执行一直在占用着workquery线程，所以导致定时器没执行到。就想问下这是为什么，为什么请求退出去了，如下代码定时器也一直在执行。