extern ssize_t recv_timeout(int sockfd, void *buf, size_t len, int flags, int timeout);
extern ssize_t send_timeout(int sockfd, void *buf, size_t len, int flags, int timeout);
extern ssize_t recv_timeout(int sockfd, void *buf, size_t len, int flags, int timeout);
extern ssize_t send_timeout(int sockfd, void *buf, size_t len, int flags, int timeout);