深入浅出Golang中select的实现原理

概述

selectchannelIOIOcaseselectmaingoroutine

select实现原理

Golangselectcasedefaultdefaultcaseselectcasecasecase

执行流程

在默认的情况下，select 语句会在编译阶段经过如下过程的处理：

case Channel selectgo scase scase case for  if case

case数据结构

selectcasescasesrc/runtime/select.go:scasecase

defaultcasechannelscaseccasechannelcasechannelcasechannel

读channel写channeldefault

scase.kind

scase.elemchannelscase.elemchannel

执行select

selectgo()selectcasecase if  selectgo() 

src/runtime/select.go:selectgo()

selectgocase pollOrder lockOrder

函数参数：

selectgo()scasepollorderscasechannellockorderselectgoscasecasecasechannelchannelscase

函数返回值：

casecasechannlecasechannel

循环

Channel selectChannel casesudog 

select  case

caseChannel

caseChannel 

Channel sendqGoroutinerecvGoroutineChannel bufrecv Channel rclose

 case Channel 

Channelrclose Channel recvqGoroutinesend Channel 

case Channel selectgoselect 

总结

selectGo select selectblockGoroutineselectcaseif ch == nil {block}; n; 

selectgopollOrderChannelOrderpollOrdercaseChannelGoroutine  Channel sendq  recvq  gopark 

selectgo