begin to address UDP reliability issues

__init__.py

@@ -1 +1 @@
-from .panda import Panda
+from .panda import Panda, PandaWifiStreaming

panda/__init__.py

@@ -28,10 +28,14 @@ def parse_can_buffer(dat):
 class PandaWifiStreaming(object):
   def __init__(self, ip="192.168.0.10", port=1338):
     self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-    self.sock.sendto("hello", (ip, port))
     self.sock.setblocking(0)
     self.ip = ip
     self.port = port
+    self.kick()
+
+  def kick(self):
+    # must be called at least every 5 seconds
+    self.sock.sendto("hello", (self.ip, self.port))
 
   def can_recv(self):
     ret = []

tests/automated/5_wifi_throughput.py

@@ -0,0 +1,41 @@
+from __future__ import print_function
+import sys
+import time
+from helpers import time_many_sends
+from panda import Panda, PandaWifiStreaming
+
+def test_high_throughput():
+  p = Panda()
+  p.set_safety_mode(Panda.SAFETY_ALLOUTPUT)
+  p.set_can_loopback(True)
+  pwifi = Panda("WIFI")
+
+  # TODO: msg_count=1000 drops packets, is this fixable?
+  for msg_count in [10,100,200]:
+    speed = 500
+    p.set_can_speed_kbps(0, speed)
+    comp_kbps = time_many_sends(p, 0, pwifi, msg_count)
+    saturation_pct = (comp_kbps/speed) * 100.0
+
+    print("HT WIFI loopback %d messages at speed %d, comp speed is %.2f, percent %.2f" % (msg_count, speed, comp_kbps, saturation_pct))
+
+def test_udp_doesnt_drop():
+  p = Panda()
+  p.set_safety_mode(Panda.SAFETY_ALLOUTPUT)
+  p.set_can_loopback(True)
+
+  pwifi = PandaWifiStreaming()
+
+  for i in range(30):
+    pwifi.kick()
+
+    speed = 500
+    p.set_can_speed_kbps(0, speed)
+    comp_kbps = time_many_sends(p, 0, pwifi, msg_count=10)
+    saturation_pct = (comp_kbps/speed) * 100.0
+
+    sys.stdout.write(".")
+    sys.stdout.flush()
+
+
+

tests/automated/helpers.py

@@ -27,24 +27,25 @@ def connect_wifi():
   # TODO: Ubuntu
   os.system("networksetup -setairportnetwork en0 %s %s" % (ssid, pw))
 
-def time_many_sends(p, bus):
-  MSG_COUNT = 100
+def time_many_sends(p, bus, precv=None, msg_count=100):
+  if precv == None:
+    precv = p
 
   st = time.time()
-  p.can_send_many([(0x1aa, 0, "\xaa"*8, bus)]*MSG_COUNT)
+  p.can_send_many([(0x1aa, 0, "\xaa"*8, bus)]*msg_count)
   r = []
 
-  while len(r) < 200 and (time.time() - st) < 3:
-    r.extend(p.can_recv())
+  while len(r) < (msg_count*2) and (time.time() - st) < 3:
+    r.extend(precv.can_recv())
 
   sent_echo = filter(lambda x: x[3] == 0x80 | bus, r)
   loopback_resp = filter(lambda x: x[3] == bus, r)
 
-  assert_equal(len(sent_echo), 100)
-  assert_equal(len(loopback_resp), 100)
+  assert_equal(len(sent_echo), msg_count)
+  assert_equal(len(loopback_resp), msg_count)
 
   et = (time.time()-st)*1000.0
-  comp_kbps = (1+11+1+1+1+4+8*8+15+1+1+1+7)*MSG_COUNT / et
+  comp_kbps = (1+11+1+1+1+4+8*8+15+1+1+1+7)*msg_count / et
 
   return comp_kbps