From 0a327854f8613b7a52a80c1f3f8fc3100fb9df58 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Tue, 21 Jul 2015 15:30:47 +0200 Subject: [PATCH] bootchart: fix negative 'timeleft' condition Fix the overrun case in sample acquistion and negative number calculations. Reported by Stefan Sauer. Fixes #642 --- src/bootchart/bootchart.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/src/bootchart/bootchart.c b/src/bootchart/bootchart.c index 3360bc85be..1625d51fa8 100644 --- a/src/bootchart/bootchart.c +++ b/src/bootchart/bootchart.c @@ -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); }