diff --git a/usock.c b/usock.c index 64eab9e..db1ddce 100644 --- a/usock.c +++ b/usock.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -130,3 +131,29 @@ int usock(int type, const char *host, const char *service) { usock_set_flags(sock, type); return sock; } + +int usock_wait_ready(int fd, int msecs) { + struct pollfd fds[1]; + int res; + + fds[0].fd = fd; + fds[0].events = POLLOUT; + + res = poll(fds, 1, msecs); + if (res < 0) { + return errno; + } else if (res == 0) { + return -ETIMEDOUT; + } else { + int err = 0; + socklen_t optlen = sizeof(err); + + res = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &optlen); + if (res) + return errno; + if (err) + return err; + } + + return 0; +} diff --git a/usock.h b/usock.h index 8345581..b0b952b 100644 --- a/usock.h +++ b/usock.h @@ -33,4 +33,15 @@ const char *usock_port(int port); int usock(int type, const char *host, const char *service); +/** + * Wait for a socket to become ready. + * + * This may be useful for users of USOCK_NONBLOCK to wait (with a timeout) + * for a socket. + * + * @param fd file descriptor of socket + * @param msecs timeout in microseconds + */ +int usock_wait_ready(int fd, int msecs); + #endif /* USOCK_H_ */