##How to use yield expression to achieve a web server
this a example to article: http://nikic.github.io/2012/12/22/Cooperative-multitasking-using-coroutines-in-PHP.html
##How to use yield expression to achieve a web server
this a example to article: http://nikic.github.io/2012/12/22/Cooperative-multitasking-using-coroutines-in-PHP.html