openpilot v0.9.6 release

date: 2024-02-21T23:02:42
master commit: 0b4d08fab8e35a264bc7383e878538f8083c33e5

common/realtime.py

@@ -0,0 +1,95 @@
+"""Utilities for reading real time clocks and keeping soft real time constraints."""
+import gc
+import os
+import time
+from collections import deque
+from typing import Optional, List, Union
+
+from setproctitle import getproctitle
+
+from openpilot.system.hardware import PC
+
+
+# time step for each process
+DT_CTRL = 0.01  # controlsd
+DT_MDL = 0.05  # model
+DT_TRML = 0.5  # thermald and manager
+DT_DMON = 0.05  # driver monitoring
+
+
+class Priority:
+  # CORE 2
+  # - modeld = 55
+  # - camerad = 54
+  CTRL_LOW = 51 # plannerd & radard
+
+  # CORE 3
+  # - boardd = 55
+  CTRL_HIGH = 53
+
+
+def set_realtime_priority(level: int) -> None:
+  if not PC:
+    os.sched_setscheduler(0, os.SCHED_FIFO, os.sched_param(level))
+
+
+def set_core_affinity(cores: List[int]) -> None:
+  if not PC:
+    os.sched_setaffinity(0, cores)
+
+
+def config_realtime_process(cores: Union[int, List[int]], priority: int) -> None:
+  gc.disable()
+  set_realtime_priority(priority)
+  c = cores if isinstance(cores, list) else [cores, ]
+  set_core_affinity(c)
+
+
+class Ratekeeper:
+  def __init__(self, rate: float, print_delay_threshold: Optional[float] = 0.0) -> None:
+    """Rate in Hz for ratekeeping. print_delay_threshold must be nonnegative."""
+    self._interval = 1. / rate
+    self._next_frame_time = time.monotonic() + self._interval
+    self._print_delay_threshold = print_delay_threshold
+    self._frame = 0
+    self._remaining = 0.0
+    self._process_name = getproctitle()
+    self._dts = deque([self._interval], maxlen=100)
+    self._last_monitor_time = time.monotonic()
+
+  @property
+  def frame(self) -> int:
+    return self._frame
+
+  @property
+  def remaining(self) -> float:
+    return self._remaining
+
+  @property
+  def lagging(self) -> bool:
+    avg_dt = sum(self._dts) / len(self._dts)
+    expected_dt = self._interval * (1 / 0.9)
+    return avg_dt > expected_dt
+
+  # Maintain loop rate by calling this at the end of each loop
+  def keep_time(self) -> bool:
+    lagged = self.monitor_time()
+    if self._remaining > 0:
+      time.sleep(self._remaining)
+    return lagged
+
+  # Monitors the cumulative lag, but does not enforce a rate
+  def monitor_time(self) -> bool:
+    prev = self._last_monitor_time
+    self._last_monitor_time = time.monotonic()
+    self._dts.append(self._last_monitor_time - prev)
+
+    lagged = False
+    remaining = self._next_frame_time - time.monotonic()
+    self._next_frame_time += self._interval
+    if self._print_delay_threshold is not None and remaining < -self._print_delay_threshold:
+      print(f"{self._process_name} lagging by {-remaining * 1000:.2f} ms")
+      lagged = True
+    self._frame += 1
+    self._remaining = remaining
+    return lagged