Laikad: Use process for parsing orbits (#24769)

* Use Process instead of Thread to fetch orbits

* small refactor

* Cleanup

selfdrive/locationd/laikad.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
-import threading
 import time
-from typing import List
+from multiprocessing import Process, Queue
+from typing import List, Optional
 
 import numpy as np
 from collections import defaultdict
@@ -27,14 +27,17 @@ class Laikad:
   def __init__(self, valid_const=("GPS", "GLONASS"), auto_update=False, valid_ephem_types=(EphemerisType.ULTRA_RAPID_ORBIT, EphemerisType.NAV)):
     self.astro_dog = AstroDog(valid_const=valid_const, auto_update=auto_update, valid_ephem_types=valid_ephem_types)
     self.gnss_kf = GNSSKalman(GENERATED_DIR)
-    self.latest_time_msg = None
+    self.orbit_p: Optional[Process] = None
+    self.orbit_q = Queue()
 
   def process_ublox_msg(self, ublox_msg, ublox_mono_time: int):
     if ublox_msg.which == 'measurementReport':
       report = ublox_msg.measurementReport
-      new_meas = read_raw_ublox(report)
       if report.gpsWeek > 0:
-        self.latest_time_msg = GPSTime(report.gpsWeek, report.rcvTow)
+        latest_msg_t = GPSTime(report.gpsWeek, report.rcvTow)
+        self.fetch_orbits(latest_msg_t + SECS_IN_MIN, block=False)
+      new_meas = read_raw_ublox(report)
+
       measurements = process_measurements(new_meas, self.astro_dog)
       pos_fix = calc_pos_fix(measurements, min_measurements=4)
       # To get a position fix a minimum of 5 measurements are needed.
@@ -104,18 +107,28 @@ class Laikad:
 
     self.gnss_kf.init_state(x_initial, covs_diag=p_initial_diag)
 
-  def orbit_thread(self, end_event: threading.Event):
-    while not end_event.is_set():
-      if self.latest_time_msg:
-        self.fetch_orbits(self.latest_time_msg + SECS_IN_MIN)
-        time.sleep(0.1)
-
-  def fetch_orbits(self, t: GPSTime):
-    if t not in self.astro_dog.orbit_fetched_times:
+  def get_orbit_data(self, t: GPSTime, queue):
     cloudlog.info(f"Start to download/parse orbits for time {t.as_datetime()}")
     start_time = time.monotonic()
     self.astro_dog.get_orbit_data(t, only_predictions=True)
     cloudlog.info(f"Done parsing orbits. Took {time.monotonic() - start_time:.2f}s")
+    queue.put((self.astro_dog.orbits, self.astro_dog.orbit_fetched_times))
+
+  def fetch_orbits(self, t: GPSTime, block):
+    if t not in self.astro_dog.orbit_fetched_times:
+      if self.orbit_p is None:
+        self.orbit_p = Process(target=self.get_orbit_data, args=(t, self.orbit_q))
+        self.orbit_p.start()
+      ret = None
+      if block:
+        ret = self.orbit_q.get(block=True)
+      elif not self.orbit_q.empty():
+        ret = self.orbit_q.get()
+
+      if ret:
+        self.astro_dog.orbits, self.astro_dog.orbit_fetched_times = ret
+        self.orbit_p.join()
+        self.orbit_p = None
 
 
 def create_measurement_msg(meas: GNSSMeasurement):
@@ -162,11 +175,7 @@ def main():
   pm = messaging.PubMaster(['gnssMeasurements'])
 
   laikad = Laikad()
-
-  end_event = threading.Event()
-  threading.Thread(target=laikad.orbit_thread, args=(end_event,)).start()
-  try:
-    while not end_event.is_set():
+  while True:
     sm.update()
 
     if sm.updated['ubloxGnss']:
@@ -174,9 +183,6 @@ def main():
       msg = laikad.process_ublox_msg(ublox_msg, sm.logMonoTime['ubloxGnss'])
       if msg is not None:
         pm.send('gnssMeasurements', msg)
-  except (KeyboardInterrupt, SystemExit):
-    end_event.set()
-    raise
 
 
 if __name__ == "__main__":

selfdrive/locationd/test/test_laikad.py

@@ -83,18 +83,14 @@ class TestLaikad(unittest.TestCase):
         if len(new_meas) != 0:
           first_gps_time = new_meas[0].recv_time
           break
-    # Pretend thread has loaded the orbits on startup by using the time of the first gps message.
-    laikad.fetch_orbits(first_gps_time)
+    # Pretend process has loaded the orbits on startup by using the time of the first gps message.
+    laikad.fetch_orbits(first_gps_time, block=True)
     self.assertEqual(29, len(laikad.astro_dog.orbits.keys()))
-    correct_msgs = verify_messages(self.logs, laikad)
-    correct_msgs_expected = 560
-    self.assertEqual(correct_msgs_expected, len(correct_msgs))
-    self.assertEqual(correct_msgs_expected, len([m for m in correct_msgs if m.gnssMeasurements.positionECEF.valid]))
 
   @unittest.skip("Use to debug live data")
   def test_laika_get_orbits_now(self):
     laikad = Laikad(auto_update=False)
-    laikad.fetch_orbits(GPSTime.from_datetime(datetime.utcnow()))
+    laikad.fetch_orbits(GPSTime.from_datetime(datetime.utcnow()), block=True)
     prn = "G01"
     self.assertLess(0, len(laikad.astro_dog.orbits[prn]))
     prn = "R01"