Function duk_trans_socket_peek_cb

Source/Utils/duk_trans_socket_unix.c:262–321

}

duk_size_t duk_trans_socket_peek_cb(void *udata) {
#if defined(USE_SELECT)
	struct timeval tm;
	fd_set rfds;
	int select_rc;
#else
	struct pollfd fds[1];
	int poll_rc;
#endif

	(void) udata;  /* not needed by the example */

#if defined(DEBUG_PRINTS)
	fprintf(stderr, "%s: udata=%p\n", __func__, (void *) udata);
	fflush(stderr);
#endif

	if (client_sock < 0) {
		return 0;
	}
#if defined(USE_SELECT)
	FD_ZERO(&rfds);
	FD_SET(client_sock, &rfds);
	tm.tv_sec = tm.tv_usec = 0;
	select_rc = select(client_sock + 1, &rfds, NULL, NULL, &tm);
	if (select_rc == 0) {
		return 0;
	} else if (select_rc == 1) {
		return 1;
	}
	goto fail;
#else  /* USE_SELECT */
	fds[0].fd = client_sock;
	fds[0].events = POLLIN;
	fds[0].revents = 0;

	poll_rc = poll(fds, 1, 0);
	if (poll_rc < 0) {
		fprintf(stderr, "%s: poll returned < 0, closing connection: %s\n",
		        __FILE__, strerror(errno));
		fflush(stderr);
		goto fail;  /* also returns 0, which is correct */
	} else if (poll_rc > 1) {
		fprintf(stderr, "%s: poll returned > 1, treating like 1\n",
		        __FILE__);
		fflush(stderr);
		return 1;  /* should never happen */
	} else if (poll_rc == 0) {
		return 0;  /* nothing to read */
	} else {
		return 1;  /* something to read */
	}
#endif  /* USE_SELECT */
 fail:
	if (client_sock >= 0) {
		(void) close(client_sock);
		client_sock = -1;
	}