C 用例
C 用例
int one = 1, idle = 60, cnt = 3;
setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one));
setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle));
setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt));系统级 tcp_keepalive_* 只影响未单独设置的连接(且对新连接生效)。