check closed channel
check closed channel

wmydz1/leaf,sinuos/leaf,freeznet/leaf,deliangyang/leaf,catinred2/leaf,horryq/leaf,linmingren/leaf,w4ngyi/leaf,GangWang/leaf,abel/leaf,name5566/leaf,voidException/leaf,yangxianjun/leaf,zhutaorun/leaf,gale320/leaf