fix for 100% CPU usage if probe connection is too fast. fix for 100% CPU usage when poll keeps monitoring already closed sockets. 
fix for 100% CPU usage if probe connection is too fast.
fix for 100% CPU usage when poll keeps monitoring already closed sockets. 

mfazliazran/slowhttptest,tectronics/slowhttptest,0x37N0w4N/slowhttptest,mentesc/slowhttptest,jack-ju/slowhttptest,jengyic/slowhttptest,yeahdongcn/slowhttptest,jack-ju/slowhttptest,Chigirin/slowhttptest,a12689851/slowhttptest,a12689851/slowhttptest,mfazliazran/slowhttptest,0x37N0w4N/slowhttptest,tectronics/slowhttptest,Chigirin/slowhttptest,yeahdongcn/slowhttptest,jengyic/slowhttptest,mentesc/slowhttptest