void
C64::synchronizeTiming()
{
const uint64_t earlyWakeup = 1500000; /* 1.5 milliseconds */
// Convert usec into kernel unit
int64_t kernelTargetTime = nanos_to_abs(nanoTargetTime);
// Check how long we're supposed to sleep
int64_t timediff = kernelTargetTime - (int64_t)mach_absolute_time();
if (timediff > 200000000 /* 0.2 sec */) {
// The emulator seems to be out of sync, so we better reset the synchronization timer
debug(2, "Emulator lost synchronization (%lld). Restarting synchronization timer.\n", timediff);
restartTimer();
// return;
}
// Sleep and update target timer
// debug(2, "%p Sleeping for %lld\n", this, kernelTargetTime - mach_absolute_time());
int64_t jitter = sleepUntil(kernelTargetTime, earlyWakeup);
nanoTargetTime += vic->getFrameDelay();
// debug(2, "Jitter = %d", jitter);
if (jitter > 1000000000 /* 1 sec */) {
// The emulator did not keep up with the real time clock. Instead of
// running behind for a long time, we reset the synchronization timer
debug(2, "Jitter exceeds limit (%lld). Restarting synchronization timer.\n", jitter);
restartTimer();
}
}
void
C64::synchronizeTiming()
{
const uint64_t earlyWakeup = 1500000; /* 1.5 milliseconds */
const uint64_t maxJitter = 1000000000; /* 1 second */
// Convert usec into kernel unit and sleep
uint64_t kernelTargetTime = nanos_to_abs(nanoTargetTime);
int64_t jitter = sleepUntil(kernelTargetTime, earlyWakeup);
// Update target time
nanoTargetTime += vic->getFrameDelay();
// debug(2, "Jitter = %d", jitter);
if (jitter > maxJitter) {
// The emulator did not keep up with the real time clock. Instead of
// running behind for a long time, we reset the synchronization timer
debug(2, "Jitter exceeds limit. Restarting synchronization timer.\n");
restartTimer();
}
#if 0
// Old sleep
// determine how long we should wait
uint64_t timeToSleep = targetTime - usec();
targetTime += vic->getFrameDelay() / 1000; // OLD
if (timeToSleep > 0) {
sleepMicrosec(timeToSleep);
} else {
restartTimer();
}
#endif
}
