main Queue 与 main Thread

Conclusion

• Main Queue IS bound to Main Thread.
• Main Thread IS NOT bound to Main Queue.

That's why in general: Main Queue Thread != Main Thread

 参考：  http://blog.krzyzanowskim.com/2016/06/03/queues-are-not-bound-to-any-specific-thread/

               http://www.tuicool.com/articles/2Y7Jj2a