throw exception on double close
throw exception on double close

hustxiaoc/tchannel,benfleis/tchannel,RyanTech/tchannel,sasa233/tchannel,bunnyblue/tchannel,chenwenbin928/tchannel,hustxiaoc/tchannel,Zirpon/tchannel,vanloswang/tchannel,chenwenbin928/tchannel,benfleis/tchannel,bunnyblue/tchannel,savaki/tchannel,i/tchannel,Zirpon/tchannel,i/tchannel,RyanTech/tchannel,benfleis/tchannel,vanloswang/tchannel,savaki/tchannel,bunnyblue/tchannel,i/tchannel,hustxiaoc/tchannel,sasa233/tchannel,RyanTech/tchannel,vanloswang/tchannel,davewhat/tchannel,sasa233/tchannel,davewhat/tchannel,savaki/tchannel,Zirpon/tchannel,chenwenbin928/tchannel