liunx系统下请问TCP_KEEPIDLE基本时间单位是秒还是毫秒呀？如果是毫秒可以吗？

int keepAlive = 1;    // 非0值，开启keepalive属性

int keepIdle = 60;    // 如该连接在60秒内没有任何数据往来,则进行此TCP层的探测

int keepInterval = 5; // 探测发包间隔为5秒

int keepCount = 3;        // 尝试探测的次数.如果第1次探测包就收到响应了,则后2次的不再发

setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, (void *)&keepAlive, sizeof(keepAlive));

setsockopt(sockfd, SOL_TCP, TCP_KEEPIDLE, (void*)&keepIdle, sizeof(keepIdle));

setsockopt(sockfd, SOL_TCP, TCP_KEEPINTVL, (void *)&keepInterval, sizeof(keepInterval));

setsockopt(sockfd, SOL_TCP, TCP_KEEPCNT, (void *)&keepCount, sizeof(keepCount)