openkylin
/
platform_system_core
mirror of https://gitee.com/openkylin/platform_system_core.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge "logd: best 2/3 filter for timezone glitches" 

am: ad9dac1c27

* commit 'ad9dac1c2795ed28f3a011182f176d852ee269ee':
  logd: best 2/3 filter for timezone glitches
This commit is contained in:
Mark Salyzyn 2015-12-10 15:45:09 -08:00 committed by android-build-merger
parent 6fa162fdf3 ad9dac1c27
commit 64f6251f60
1 changed files with 25 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
logd/LogKlog.cpp
View File

@ -778,6 +778,31 @@ int LogKlog::log(const char *buf, size_t len) {
memcpy(np, p, b);
np[b] = '\0';
if (!isMonotonic()) {
// Watch out for singular race conditions with timezone causing near
// integer quarter-hour jumps in the time and compensate accordingly.
// Entries will be temporal within near_seconds * 2. b/21868540
static uint32_t vote_time[3];
vote_time[2] = vote_time[1];
vote_time[1] = vote_time[0];
vote_time[0] = now.tv_sec;
if (vote_time[1] && vote_time[2]) {
static const unsigned near_seconds = 10;
static const unsigned timezones_seconds = 900;
int diff0 = (vote_time[0] - vote_time[1]) / near_seconds;
unsigned abs0 = (diff0 < 0) ? -diff0 : diff0;
int diff1 = (vote_time[1] - vote_time[2]) / near_seconds;
unsigned abs1 = (diff1 < 0) ? -diff1 : diff1;
if ((abs1 <= 1) && // last two were in agreement on timezone
((abs0 + 1) % (timezones_seconds / near_seconds)) <= 2) {
abs0 = (abs0 + 1) / (timezones_seconds / near_seconds) *
timezones_seconds;
now.tv_sec -= (diff0 < 0) ? -abs0 : abs0;
}
}
}
// Log message
int rc = logbuf->log(LOG_ID_KERNEL, now, uid, pid, tid, newstr,
(unsigned short) n);