annotate loadtools/secondprog.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 064d4eedb3a6
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
204
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * This module contains the code for passing the serial channel to a
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * second program, used by fc-iram and fc-xram.
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 */
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 #include <stdio.h>
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 #include <stdlib.h>
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 #include <unistd.h>
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 extern char **passon_argv;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 extern int passon_argc;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 exec_2nd_prog()
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 {
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 char **execp_argv;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 char **sp, **dp;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 extern int target_fd;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 char desc_arg[16];
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 sprintf(desc_arg, "-d%d", target_fd);
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 execp_argv = (char **) malloc(sizeof(char *) * (passon_argc + 2));
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 if (!execp_argv) {
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 perror("malloc argv for execvp");
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 exit(1);
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 }
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 sp = passon_argv;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 dp = execp_argv;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 *dp++ = *sp++;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 *dp++ = desc_arg;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 while (*sp)
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 *dp++ = *sp++;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 *dp = NULL;
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 execvp(execp_argv[0], execp_argv);
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 fprintf(stderr, "Unable to execvp %s\n", passon_argv[0]);
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 exit(1);
064d4eedb3a6 loadtools: second program invokation support added to fc-iram like in fc-xram
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 }