picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

bootchart: fix negative 'timeleft' condition

Browse source 
Fix the overrun case in sample acquistion and negative number calculations.

Reported by Stefan Sauer.

Fixes #642
This commit is contained in:
Daniel Mack 2015-07-21 15:30:47 +02:00
parent 81fc63daa4
commit 0a327854f8
1 changed files with 6 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
src/bootchart/bootchart.c
View file

@ -387,9 +387,6 @@ int main(int argc, char *argv[]) {
for (samples = 0; !exiting && samples < arg_samples_len; samples++) {
int res;
double sample_stop;
struct timespec req;
time_t newint_s;
long newint_ns;
double elapsed;
double timeleft;
@ -427,18 +424,17 @@ int main(int argc, char *argv[]) {
elapsed = (sample_stop - sampledata->sampletime) * 1000000000.0;
timeleft = interval - elapsed;
newint_s = (time_t)(timeleft / 1000000000.0);
newint_ns = (long)(timeleft - (newint_s * 1000000000.0));
/*
* check if we have not consumed our entire timeslice. If we
* do, don't sleep and take a new sample right away.
* we'll lose all the missed samples and overrun our total
* time
*/
if (newint_ns > 0 || newint_s > 0) {
req.tv_sec = newint_s;
req.tv_nsec = newint_ns;
if (timeleft > 0) {
struct timespec req;
req.tv_sec = (time_t)(timeleft / 1000000000.0);
req.tv_nsec = (long)(timeleft - (req.tv_sec * 1000000000.0));
res = nanosleep(&req, NULL);
if (res) {
@ -452,7 +448,7 @@ int main(int argc, char *argv[]) {
} else {
overrun++;
/* calculate how many samples we lost and scrap them */
arg_samples_len -= (int)(newint_ns / interval);
arg_samples_len -= (int)(-timeleft / interval);
}
LIST_PREPEND(link, head, sampledata);
}