Hey,
If we treat tlist[] like an array instead of a list, we can
eliminate a lot of special cases and duplicate calls in shutdown(8)'s
countdown loop().
We add a spare index at the beginning of tlist[] to accomodate
offsets greater than 10 hours and insert our offset into tlist[]
in an initial loop. With that done we can cut out all of the
duplicate calls and most of the extra logic and invoke timewarn(),
nolog(), and sleep() once each in a master countdown loop.
While we're here I think we ought to make everything in tlist[] a
time_t to eliminate the casting in loop(). offset is a time_t, so
there's just less type friction. It also makes things simpler for
some later diffs I have planned. But so, int -> time_t, hence
sleep -> nanosleep.
ok?
--
Scott Cheloha
Index: sbin/shutdown/shutdown.c
===================================================================
RCS file: /cvs/src/sbin/shutdown/shutdown.c,v
retrieving revision 1.48
diff -u -p -r1.48 shutdown.c
--- sbin/shutdown/shutdown.c 24 Feb 2018 20:00:07 -0000 1.48
+++ sbin/shutdown/shutdown.c 24 Feb 2018 23:57:54 -0000
@@ -64,8 +64,10 @@
#define S *1
#define NOLOG_TIME 5*60
struct interval {
- int timeleft, timetowait;
+ time_t timeleft;
+ time_t timetowait;
} tlist[] = {
+ { 0, 0 },
{ 10 H, 5 H },
{ 5 H, 3 H },
{ 2 H, 1 H },
@@ -79,6 +81,7 @@ struct interval {
{ 30 S, 30 S },
{ 0, 0 }
};
+const int tlistlen = { sizeof(tlist) / sizeof(tlist[0]) };
#undef H
#undef M
#undef S
@@ -96,7 +99,7 @@ void getoffset(char *);
void __dead loop(void);
void nolog(void);
void timeout(int);
-void timewarn(int);
+void timewarn(time_t);
void usage(void);
int
@@ -229,40 +232,38 @@ main(int argc, char *argv[])
void
loop(void)
{
- struct interval *tp;
- u_int sltime;
- int logged;
-
- if (offset <= NOLOG_TIME) {
- logged = 1;
- nolog();
- } else
- logged = 0;
- tp = tlist;
- if (tp->timeleft < offset)
- (void)sleep((u_int)(offset - tp->timeleft));
- else {
- while (offset < tp->timeleft)
- ++tp;
- /*
- * Warn now, if going to sleep more than a fifth of
- * the next wait time.
- */
- if ((sltime = offset - tp->timeleft)) {
- if (sltime > tp->timetowait / 5)
- timewarn(offset);
- (void)sleep(sltime);
+ struct timespec timeout;
+ int broadcast, i, logged;
+
+ broadcast = 1;
+
+ for (i = 0; i < tlistlen - 1; i++) {
+ if (offset > tlist[i + 1].timeleft) {
+ tlist[i].timeleft = offset;
+ tlist[i].timetowait = offset - tlist[i + 1].timeleft;
+ break;
}
}
- for (;; ++tp) {
- timewarn(tp->timeleft);
- if (!logged && tp->timeleft <= NOLOG_TIME) {
+
+ /*
+ * Don't spam the users: skip our offset's warning broadcast if
+ * there's a broadcast scheduled after ours and it's relatively
+ * imminent.
+ */
+ if (offset > 0 && tlist[i].timetowait < tlist[i + 1].timetowait / 5)
+ broadcast = 0;
+
+ for (logged = 0; i < tlistlen; i++) {
+ if (broadcast)
+ timewarn(tlist[i].timeleft);
+ broadcast = 1;
+ if (!logged && tlist[i].timeleft <= NOLOG_TIME) {
logged = 1;
nolog();
}
- (void)sleep((u_int)tp->timetowait);
- if (!tp->timeleft)
- break;
+ timeout.tv_sec = tlist[i].timetowait;
+ timeout.tv_nsec = 0;
+ nanosleep(&timeout, NULL);
}
die_you_gravy_sucking_pig_dog();
}
@@ -273,7 +274,7 @@ static char *restricted_environ[] = {
};
void
-timewarn(int timeleft)
+timewarn(time_t timeleft)
{
static char hostname[HOST_NAME_MAX+1];
static int first;
@@ -321,7 +322,7 @@ timewarn(int timeleft)
tm->tm_hour, tm->tm_min);
} else if (timeleft > 59)
dprintf(fd[1], "System going down in %d minute%s\n\n",
- timeleft / 60, (timeleft > 60) ? "s" : "");
+ (int)(timeleft / 60), (timeleft > 60) ? "s" : "");
else if (timeleft)
dprintf(fd[1], "System going down in 30 seconds\n\n");
else
