$ strace.exe -o strace_ccs2_s.out ccs2.exe s Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" Wait on accept from 3 (aborted with Windows Task Manager) $ strace.exe -o strace_ccs3.out ccs3.exe Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with fcntl() O_NONBLOCK 00000000000000100000000000000000 oldflags 01000000000000001000000000000000 (aborted with Windows Task Manager) $ strace.exe -o strace_ccs3_i.out ccs3.exe i Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with ioctl() Try accept from 3 set 3 nonblock flag to 0 with ioctl() Accepted new connection on 5 Connected :) Success $ strace.exe -o strace_ccs3_i2.out ccs3.exe i Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with ioctl() Try accept from 3 (aborted with Windows Task Manager) $ strace.exe -o strace_ccs3_i3.out ccs3.exe i Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with ioctl() Try accept from 3 set 3 nonblock flag to 0 with ioctl() Accepted new connection on 5 Connected :) Success $ strace.exe -o strace_ccs3_i4.out ccs3.exe i Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with ioctl() Try accept from 3 (aborted with Windows Task Manager) $ strace.exe -o strace_ccs3_i5.out ccs3.exe i Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with ioctl() Try accept from 3 set 3 nonblock flag to 0 with ioctl() Accepted new connection on 5 Connected :) Success $ strace.exe -o strace_ccs3_6.out ccs3.exe Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with fcntl() O_NONBLOCK 00000000000000100000000000000000 oldflags 01000000000000001000000000000000 newflags 01000000000000101000000000000000 Try accept from 3 (aborted with Windows Task Manager) $ strace.exe -o strace_ccs3_7.out ccs3.exe Threaded Bound and listening to "check_sockets_port" on fd 3 Wait on select Connecting 4 to "check_sockets_port" set 3 nonblock flag to 1 with fcntl() O_NONBLOCK 00000000000000100000000000000000 oldflags 01000000000000001000000000000000 newflags 01000000000000101000000000000000 Try accept from 3 (aborted with Windows Task Manager) $ grep socket is now|accept strace_ccs3* strace_ccs3.out: 209 1089312 [unknown (0xFAC)] ccs3 1228 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3.out:12917 1138561 [unknown (0x708)] ccs3 1228 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3.out: 171 1145501 [unknown (0x708)] ccs3 1228 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_6.out: 174 1090593 [unknown (0xF20)] ccs3 2752 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_6.out:13447 1139294 [unknown (0xE24)] ccs3 2752 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_6.out: 152 1145107 [unknown (0xE24)] ccs3 2752 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_7.out: 210 1088912 [unknown (0xCA8)] ccs3 4076 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_7.out:14441 1141252 [unknown (0xF2C)] ccs3 4076 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_7.out: 222 1146406 [unknown (0xF2C)] ccs3 4076 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i.out: 214 1093756 [unknown (0xAE8)] ccs3 2256 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i.out: 182 1131344 [unknown (0x4D0)] ccs3 2256 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i.out: 149 1180072 [unknown (0x4D0)] ccs3 2256 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i.out: 441 1183054 [unknown (0x4D0)] ccs3 2256 fhandler_socket::accept: res 5 strace_ccs3_i.out: 186 1183240 [unknown (0x4D0)] ccs3 2256 cygwin_accept: 5 = accept (3, 0x0, 0x0) strace_ccs3_i.out: 155 1183959 [unknown (0x4D0)] ccs3 2256 fhandler_socket::ioctl: socket is now blocking strace_ccs3_i.out: 241 1192071 [unknown (0xAE8)] ccs3 2256 fhandler_socket::ioctl: socket is now blocking strace_ccs3_i2.out: 206 1091705 [unknown (0x6C0)] ccs3 1544 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i2.out: 210 1127669 [unknown (0xAD8)] ccs3 1544 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i2.out: 163 1132606 [unknown (0xAD8)] ccs3 1544 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i3.out: 211 1090323 [unknown (0x844)] ccs3 3152 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i3.out: 190 1126651 [unknown (0xCC)] ccs3 3152 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i3.out: 275 1172577 [unknown (0xCC)] ccs3 3152 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i3.out: 228 1175465 [unknown (0xCC)] ccs3 3152 fhandler_socket::accept: res 5 strace_ccs3_i3.out: 163 1175628 [unknown (0xCC)] ccs3 3152 cygwin_accept: 5 = accept (3, 0x0, 0x0) strace_ccs3_i3.out: 176 1176238 [unknown (0xCC)] ccs3 3152 fhandler_socket::ioctl: socket is now blocking strace_ccs3_i3.out: 279 1180751 [unknown (0x844)] ccs3 3152 fhandler_socket::ioctl: socket is now blocking strace_ccs3_i4.out: 222 1092423 [unknown (0xD78)] ccs3 3824 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i4.out: 430 1128120 [unknown (0xF84)] ccs3 3824 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i4.out: 160 1134311 [unknown (0xF84)] ccs3 3824 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i5.out: 212 1092374 [unknown (0xEC8)] ccs3 3144 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i5.out: 216 1129834 [unknown (0xCB0)] ccs3 3144 fhandler_socket::ioctl: socket is now nonblocking strace_ccs3_i5.out: 251 1177332 [unknown (0xCB0)] ccs3 3144 fhandler_socket::af_local_accept: af_local_accept called strace_ccs3_i5.out: 236 1180187 [unknown (0xCB0)] ccs3 3144 fhandler_socket::accept: res 5 strace_ccs3_i5.out: 154 1180341 [unknown (0xCB0)] ccs3 3144 cygwin_accept: 5 = accept (3, 0x0, 0x0) strace_ccs3_i5.out: 201 1181176 [unknown (0xCB0)] ccs3 3144 fhandler_socket::ioctl: socket is now blocking strace_ccs3_i5.out: 480 1183690 [unknown (0xEC8)] ccs3 3144 fhandler_socket::ioctl: socket is now blocking $ grep connect strace_ccs3* strace_ccs3.out: 215 1118759 [unknown (0xFAC)] ccs3 1228 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_6.out: 213 1120053 [unknown (0xF20)] ccs3 2752 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_7.out: 215 1117101 [unknown (0xCA8)] ccs3 4076 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i.out: 211 1123530 [unknown (0xAE8)] ccs3 2256 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i.out: 157 1138096 [unknown (0xAE8)] ccs3 2256 fhandler_socket::af_local_connect: af_local_connect called strace_ccs3_i.out: 169 1192392 [unknown (0xAE8)] ccs3 2256 cygwin_connect: 0 = connect (4, 0x1920CCE0, 20) strace_ccs3_i2.out: 154 1102976 [unknown (0x6C0)] ccs3 1544 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i3.out: 208 1100967 [unknown (0x844)] ccs3 3152 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i3.out: 271 1132738 [unknown (0x844)] ccs3 3152 fhandler_socket::af_local_connect: af_local_connect called strace_ccs3_i3.out: 132 1181026 [unknown (0x844)] ccs3 3152 cygwin_connect: 0 = connect (4, 0x1920CCE0, 20) strace_ccs3_i4.out: 223 1120245 [unknown (0xD78)] ccs3 3824 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i5.out: 2472 1123293 [unknown (0xEC8)] ccs3 3144 __set_winsock_errno: connect:775 - winsock error 10036 -> errno 119 strace_ccs3_i5.out: 156 1137364 [unknown (0xEC8)] ccs3 3144 fhandler_socket::af_local_connect: af_local_connect called strace_ccs3_i5.out: 143 1184034 [unknown (0xEC8)] ccs3 3144 cygwin_connect: 0 = connect (4, 0x1920CCE0, 20)