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

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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
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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)

1
client/displayservers/X11/x11.h
View File

@ -42,6 +42,7 @@ struct X11DSState
int xpresentOp;
bool jitRender;
_Atomic(uint64_t) presentMsc, presentUst;
uint32_t presentSerial;
Pixmap presentPixmap;
XserverRegion presentRegion;