Mirrored_Repos/LookingGlass
1
0
Fork 0
mirror of https://github.com/gnif/LookingGlass.git synced 2024-11-10 08:38:20 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[client] x11: move sleep and calibration code outside of the event loop

Browse Source 
Sleeping in the x11 event loop is not ideal as it will introduce latency
when processing other events, instead do this in the waitFrame handler.
This commit is contained in:
Geoffrey McRae 2021-08-04 06:30:21 +10:00
parent 6933c278ce
commit 0f7fa32d12
2 changed files with 75 additions and 66 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

128
client/displayservers/X11/x11.c
View File

@ -1041,72 +1041,15 @@ static void x11XInputEvent(XGenericEventCookie *cookie)
static void x11XPresentEvent(XGenericEventCookie *cookie)
{
#define CALIBRATION_COUNT 200
uint64_t deltats = 0;
uint64_t deltamsc = 0;
switch(cookie->evtype)
{
case PresentCompleteNotify:
{
x11DoPresent();
XPresentCompleteNotifyEvent * e = cookie->data;
/* calibrate a delay to push our presentation time forward as far as
* possible without skipping frames */
static int calibrate = 0;
static uint64_t lastts = 0;
static uint64_t lastmsc = 0;
static uint64_t delay = 0;
if (lastts)
{
deltats = e->ust - lastts;
deltamsc = e->msc - lastmsc;
if (calibrate == 0)
{
if (!delay)
delay = deltats / 2;
else
{
/* increase the delay until we see a skip */
if (deltamsc < 2)
delay += 100;
else
{
delay -= 100;
++calibrate;
}
}
}
else
{
if (calibrate < CALIBRATION_COUNT)
{
/* every skip we back off the delay */
if (deltamsc > 1)
{
delay -= 100;
calibrate = 1;
}
/* if we have finished, print out the delay */
if (++calibrate == CALIBRATION_COUNT)
DEBUG_INFO("Calibration done, delay = %lu us", delay);
}
}
}
lastts = e->ust;
lastmsc = e->msc;
/* minor adjustments if we are still seeing odd skips */
if (deltamsc > 1)
delay -= 10;
usleep(delay);
atomic_store(&x11.presentMsc, e->msc);
atomic_store(&x11.presentUst, e->ust);
lgSignalEvent(x11.frameEvent);
x11DoPresent();
break;
}
}
@ -1187,7 +1130,72 @@ static void x11GLSwapBuffers(void)
static void x11WaitFrame(void)
{
/* wait until we are woken up by the present event */
lgWaitEvent(x11.frameEvent, TIMEOUT_INFINITE);
#define CALIBRATION_COUNT 400
const uint64_t ust = atomic_load(&x11.presentUst);
const uint64_t msc = atomic_load(&x11.presentMsc);
/* calibrate a delay to push our presentation time forward as far as
* possible without skipping frames */
static int calibrate = 0;
static uint64_t lastts = 0;
static uint64_t lastmsc = 0;
static uint64_t delay = 0;
uint64_t deltats = 0;
uint64_t deltamsc = 0;
if (lastts)
{
deltats = ust - lastts;
deltamsc = msc - lastmsc;
if (calibrate == 0)
{
if (!delay)
delay = deltats / 2;
else
{
/* increase the delay until we see a skip */
if (deltamsc < 2)
delay += 100;
else
{
delay -= 100;
++calibrate;
deltamsc = 0;
}
}
}
else
{
if (calibrate < CALIBRATION_COUNT)
{
/* every skip we back off the delay */
if (deltamsc > 1)
{
delay -= 100;
calibrate = 1;
deltamsc = 0;
}
/* if we have finished, print out the delay */
if (++calibrate == CALIBRATION_COUNT)
DEBUG_INFO("Calibration done, delay = %lu us", delay);
}
}
}
lastts = ust;
lastmsc = msc;
/* minor adjustments if we are still seeing odd skips */
if (deltamsc > 1)
delay -= 10;
struct timespec ts = { .tv_nsec = delay * 1000 };
while(nanosleep(&ts, &ts)) {};
}
static void x11StopWaitFrame(void)

13
client/displayservers/X11/x11.h
View File

@ -40,12 +40,13 @@ struct X11DSState
Window window;
XVisualInfo * visual;
int xpresentOp;
bool jitRender;
uint32_t presentSerial;
Pixmap presentPixmap;
XserverRegion presentRegion;
LGEvent * frameEvent;
int xpresentOp;
bool jitRender;
_Atomic(uint64_t) presentMsc, presentUst;
uint32_t presentSerial;
Pixmap presentPixmap;
XserverRegion presentRegion;
LGEvent * frameEvent;
LGThread * eventThread;