def __init__(self, rate, print_delay_threshold=0.):
"""Rate in Hz for ratekeeping. print_delay_threshold must be nonnegative."""
self._interval = 1. / rate
self._next_frame_time = sec_since_boot() + self._interval
self._print_delay_threshold = print_delay_threshold
self._frame = 0
self._remaining = 0
self._process_name = multiprocessing.current_process().name
def monitor_time(self):
lagged = False
remaining = self._next_frame_time - sec_since_boot()
self._next_frame_time += self._interval
if self._print_delay_threshold is not None and remaining < -self._print_delay_threshold:
print("%s lagging by %.2f ms" % (self._process_name, -remaining * 1000))
lagged = True
self._frame += 1
self._remaining = remaining
return lagged
