How to skip time when closing a socket connection_ Wait status of wait

Cause analysis ：

socket It will not be retracted immediately after closing , But to experience a TIME_WAIT The stage of .windows You can reach up to 4 minute . Rebinding this port at this time will cause an error .

Mode one ：

Set up SO_REUSEADDR

if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
	return -1;
	
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) {
    
	close(fd);
	return -1;
}

Mode two ：

stay closesocket When , Use setsockopt Set up SO_DONTLINGER.

int z; 		 /* Status code*/ 
int s;       /* Socket s */
struct linger so_linger;
...
so_linger.l_onoff = TRUE;
so_linger.l_linger = 30;   // 30 Time out of seconds 
z = setsockopt(s,
    SOL_SOCKET,
    SO_LINGER,
    &so_linger,
    sizeof so_linger);
if ( z )
   perror("setsockopt(2)");

this l Two methods can be skipped TIME_WAIT The stage of , After the client restarts, it can connect quickly . This setting is usually used to enhance the robustness of network programs .