Refactor main()

We remove the hack with the sleep and global "delay"-variable and use a
monotonic clock to derive the desired monotonic properties of the tool.
Inside each function that demands a personal delay we can then just do a
nanosleep() and be done with it.
It's a shame that timespec is so ugly to work with, but there's really
no way to make it more beautiful. However, at this cost though we
finally can set the interval times in milliseconds and not only just
seconds.

We remove setlocale(), because nothing good ever came out of this
function.

Besides that we have some more code refactoring, especially in the
argument loop which saves us a bit of complexity.
This commit is contained in:
Laslo Hunhold 2017-08-13 23:21:23 +02:00 committed by Aaron Marcher
parent 3468a6e368
commit 796b661284
No known key found for this signature in database
GPG key ID: 74B048E5C2474F9A
2 changed files with 40 additions and 35 deletions

View file

@ -1,7 +1,7 @@
/* See LICENSE file for copyright and license details. */ /* See LICENSE file for copyright and license details. */
/* how often to update the statusbar (min value == 1) */ /* interval between updates (in ms) */
static const int update_interval = 1; static const int interval = 1000;
/* text to show if no value can be retrieved */ /* text to show if no value can be retrieved */
static const char unknown_str[] = "n/a"; static const char unknown_str[] = "n/a";

View file

@ -5,7 +5,6 @@
#include <ifaddrs.h> #include <ifaddrs.h>
#include <limits.h> #include <limits.h>
#include <linux/wireless.h> #include <linux/wireless.h>
#include <locale.h>
#include <netdb.h> #include <netdb.h>
#include <pwd.h> #include <pwd.h>
#include <signal.h> #include <signal.h>
@ -71,7 +70,6 @@ static const char *wifi_perc(const char *iface);
static const char *wifi_essid(const char *iface); static const char *wifi_essid(const char *iface);
char *argv0; char *argv0;
static unsigned short int delay = 0;
static unsigned short int done; static unsigned short int done;
static Display *dpy; static Display *dpy;
@ -196,6 +194,7 @@ cpu_freq(void)
static const char * static const char *
cpu_perc(void) cpu_perc(void)
{ {
struct timespec delay;
int n, perc; int n, perc;
long double a[4], b[4]; long double a[4], b[4];
FILE *fp; FILE *fp;
@ -210,8 +209,9 @@ cpu_perc(void)
if (n != 4) if (n != 4)
return unknown_str; return unknown_str;
delay++; delay.tv_sec = (interval / 2) / 1000;
sleep(delay); delay.tv_nsec = ((interval / 2) % 1000) * 1000000;
nanosleep(&delay, NULL);
fp = fopen("/proc/stat", "r"); fp = fopen("/proc/stat", "r");
if (fp == NULL) { if (fp == NULL) {
@ -842,6 +842,14 @@ terminate(const int signo)
done = 1; done = 1;
} }
static void
difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
{
res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
res->tv_nsec = a->tv_nsec - b->tv_nsec +
(a->tv_nsec < b->tv_nsec) * 1000000000;
}
static void static void
usage(void) usage(void)
{ {
@ -852,12 +860,11 @@ usage(void)
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
struct arg argument;
struct sigaction act; struct sigaction act;
struct timespec start, current, diff, intspec, wait;
size_t i, len; size_t i, len;
int sflag = 0; int sflag = 0;
char status_string[MAXLEN]; char status[MAXLEN];
char *element;
ARGBEGIN { ARGBEGIN {
case 's': case 's':
@ -876,44 +883,42 @@ main(int argc, char *argv[])
sigaction(SIGINT, &act, NULL); sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL); sigaction(SIGTERM, &act, NULL);
if (!sflag) { if (!sflag && !(dpy = XOpenDisplay(NULL))) {
dpy = XOpenDisplay(NULL);
if (!dpy) {
fprintf(stderr, "slstatus: cannot open display"); fprintf(stderr, "slstatus: cannot open display");
exit(1); return 1;
} }
}
setlocale(LC_ALL, "");
while (!done) { while (!done) {
status_string[0] = '\0'; clock_gettime(CLOCK_MONOTONIC, &start);
for (element = status_string, i = len = 0; i < LEN(args); status[0] = '\0';
++i, element += len) { for (i = len = 0; i < LEN(args); i++) {
argument = args[i]; len += snprintf(status + len, sizeof(status) - len,
len = snprintf(element, sizeof(status_string)-1 - len, args[i].fmt, args[i].func(args[i].args));
argument.fmt,
argument.func(argument.args)); if (len >= sizeof(status)) {
if (len >= sizeof(status_string)) { status[sizeof(status) - 1] = '\0';
status_string[sizeof(status_string)-1] = '\0';
break;
} }
} }
if (sflag) { if (sflag) {
printf("%s\n", status_string); printf("%s\n", status);
} else { } else {
XStoreName(dpy, DefaultRootWindow(dpy), status_string); XStoreName(dpy, DefaultRootWindow(dpy), status);
XSync(dpy, False); XSync(dpy, False);
} }
if ((update_interval - delay) <= 0) { if (!done) {
delay = 0; clock_gettime(CLOCK_MONOTONIC, &current);
continue; difftimespec(&diff, &current, &start);
} else {
sleep(update_interval - delay); intspec.tv_sec = interval / 1000;
delay = 0; intspec.tv_nsec = (interval % 1000) * 1000000;
difftimespec(&wait, &intspec, &diff);
if (wait.tv_sec >= 0) {
nanosleep(&wait, NULL);
}
} }
} }