You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
75 lines
2.1 KiB
75 lines
2.1 KiB
6 years ago
|
"""Utilities for reading real time clocks and keeping soft real time constraints."""
|
||
|
|
import os
|
||
|
|
import time
|
||
|
|
import platform
|
||
|
|
import subprocess
|
||
|
|
import multiprocessing
|
||
|
|
from cffi import FFI
|
||
|
|
|
||
|
|
from common.common_pyx import sec_since_boot # pylint: disable=no-name-in-module, import-error
|
||
|
|
|
||
|
|
|
||
|
|
# time step for each process
|
||
|
|
DT_CTRL = 0.01 # controlsd
|
||
|
|
DT_MDL = 0.05 # model
|
||
|
|
DT_DMON = 0.1 # driver monitoring
|
||
|
|
DT_TRML = 0.5 # thermald and manager
|
||
|
|
|
||
|
|
|
||
|
|
ffi = FFI()
|
||
|
|
ffi.cdef("long syscall(long number, ...);")
|
||
|
|
libc = ffi.dlopen(None)
|
||
|
|
|
||
|
|
|
||
|
|
def set_realtime_priority(level):
|
||
|
|
if os.getuid() != 0:
|
||
|
|
print("not setting priority, not root")
|
||
|
|
return
|
||
|
|
if platform.machine() == "x86_64":
|
||
|
|
NR_gettid = 186
|
||
|
|
elif platform.machine() == "aarch64":
|
||
|
|
NR_gettid = 178
|
||
|
|
else:
|
||
|
|
raise NotImplementedError
|
||
|
|
|
||
|
|
tid = libc.syscall(NR_gettid)
|
||
|
|
return subprocess.call(['chrt', '-f', '-p', str(level), str(tid)])
|
||
|
|
|
||
|
|
|
||
|
|
class Ratekeeper():
|
||
|
|
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
|
||
|
|
|
||
|
|
@property
|
||
|
|
def frame(self):
|
||
|
|
return self._frame
|
||
|
|
|
||
|
|
@property
|
||
|
|
def remaining(self):
|
||
|
|
return self._remaining
|
||
|
|
|
||
|
|
# Maintain loop rate by calling this at the end of each loop
|
||
|
|
def keep_time(self):
|
||
|
|
lagged = self.monitor_time()
|
||
|
|
if self._remaining > 0:
|
||
|
|
time.sleep(self._remaining)
|
||
|
|
return lagged
|
||
|
|
|
||
|
|
# this only monitor the cumulative lag, but does not enforce a rate
|
||
|
|
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
|