[client] check for clock drift and correct for it

Fixes #224
This commit is contained in:
Geoffrey McRae 2020-01-06 20:36:45 +11:00
parent 45ee79014d
commit 9282ed19b2
2 changed files with 29 additions and 1 deletions

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@ -1 +1 @@
B1-52-g0dc0e6490c+1 B1-54-g5033d17990+1

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@ -137,11 +137,39 @@ static int renderThread(void * unused)
/* signal to other threads that the renderer is ready */ /* signal to other threads that the renderer is ready */
lgSignalEvent(e_startup); lgSignalEvent(e_startup);
unsigned int resyncCheck = 0;
struct timespec time; struct timespec time;
clock_gettime(CLOCK_MONOTONIC, &time); clock_gettime(CLOCK_MONOTONIC, &time);
while(state.running) while(state.running)
{ {
// if our clock is too far out of sync, resync it
// this can happen when switching to/from a TTY, or due to clock drift
// we only check this once every 100 frames
if (++resyncCheck == 100)
{
resyncCheck = 0;
struct timespec tmp;
clock_gettime(CLOCK_MONOTONIC, &tmp);
if (tmp.tv_nsec - time.tv_nsec < 0)
{
tmp.tv_sec -= time.tv_sec - 1;
tmp.tv_nsec = 1000000000 + tmp.tv_nsec - time.tv_nsec;
}
else
{
tmp.tv_sec -= time.tv_sec;
tmp.tv_nsec -= time.tv_nsec;
}
const unsigned long diff = tmp.tv_sec * 1000000000 + tmp.tv_nsec;
if (diff > state.frameTime)
{
DEBUG_INFO("Timer drift detected, %lu is > %lu", diff, state.frameTime);
clock_gettime(CLOCK_MONOTONIC, &time);
}
}
if (state.lgrResize) if (state.lgrResize)
{ {
if (state.lgr) if (state.lgr)