FreeCalypso > hg > freecalypso-tools
view rvinterf/libasync/interf.c @ 407:19e5a3e2f9c0
fcup-settime: moved time() retrieval a little closer to the output
A fundamental problem with all simple time transfer tools is that there is
always some delay between the time retrieval on the source system and that
transmitted time being set on the destination, and the resulting time
on the destination system is off by that delay amount. This delay cannot
be fully eliminated when working in a simple environment like ours,
but we should make our best effort to minimize it. In the present case,
moving the atinterf_init() call before the time() retrieval should make
a teensy-tiny improvement.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sat, 11 Aug 2018 21:52:17 +0000 |
parents | 09b4fd9b3827 |
children |
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/* * This module implements the link to rvinterf. */ #include <sys/types.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include "localsock.h" #include "exitcodes.h" extern int sock; u_char rvi_msg[LOCALSOCK_MAX_MSG]; int rvi_msg_len; static int rx_state, rx_left; static u_char *rx_ptr; void localsock_prep_for_length_rx() { rx_state = 0; rx_ptr = rvi_msg; rx_left = 2; } static void prep_for_message_rx() { rx_state = 1; rx_ptr = rvi_msg; rx_left = rvi_msg_len; } void process_msg_from_rvinterf() { switch (rvi_msg[0]) { case RVI2CLI_PKT_FROM_TARGET: process_pkt_from_target(); return; case RVI2CLI_LOCAL_CMD_RESP: if (rvi_msg_len < 2) goto bad; if (rvi_msg[1] == '+') return; tty_cleanup(); fprintf(stderr, "Error from rvinterf: %.*s\n", rvi_msg_len - 1, rvi_msg + 1); exit(ERROR_RVINTERF); default: bad: tty_cleanup(); fprintf(stderr, "Error: unexpected message type %02X from rvinterf\n", rvi_msg[0]); exit(ERROR_RVINTERF); } } void handle_rvinterf_input() { int cc; cc = read(sock, rx_ptr, rx_left); if (cc <= 0) { tty_cleanup(); perror("read from rvinterf socket"); exit(ERROR_RVINTERF); } rx_ptr += cc; rx_left -= cc; if (rx_left) return; /* got the thing, process it */ if (rx_state) { process_msg_from_rvinterf(); localsock_prep_for_length_rx(); } else { rvi_msg_len = rvi_msg[0] << 8 | rvi_msg[1]; if (rvi_msg_len < 1 || rvi_msg_len > LOCALSOCK_MAX_MSG) { tty_cleanup(); fprintf(stderr, "Invalid length from rvinterf: %02X%02X\n", rvi_msg[0], rvi_msg[1]); exit(ERROR_RVINTERF); } prep_for_message_rx(); } } void send_pkt_to_target(pkt, pktlen) u_char *pkt; { u_char hdrbuf[3]; int len1; len1 = pktlen + 1; hdrbuf[0] = len1 >> 8; hdrbuf[1] = len1 & 0xFF; hdrbuf[2] = CLI2RVI_PKT_TO_TARGET; write(sock, hdrbuf, 3); write(sock, pkt, pktlen); }