autotest: use idle_hooks to prevent lockup

Tools/autotest/arducopter.py

@@ -286,6 +286,7 @@ def fly_ArduCopter(viewerip=None):
         print("Failed to start mavlink connection on 127.0.0.1:19550" % msg)
         raise
     mav.message_hooks.append(message_hook)
+    mav.idle_hooks.append(idle_hook)
 
 
     failed = False

Tools/autotest/common.py

@@ -4,17 +4,21 @@ import util, pexpect, time, math
 # messages. This keeps the output to stdout flowing
 expect_list = []
 
-def message_hook(mav, msg):
-    '''called as each mavlink msg is received'''
+def idle_hook(mav):
+    '''called when waiting for a mavlink message'''
     global expect_list
-#    if msg.get_type() in [ 'NAV_CONTROLLER_OUTPUT', 'GPS_RAW' ]:
-#        print(msg)
     for p in expect_list:
         try:
             p.read_nonblocking(100, timeout=0)
         except pexpect.TIMEOUT:
             pass
 
+def message_hook(mav, msg):
+    '''called as each mavlink msg is received'''
+#    if msg.get_type() in [ 'NAV_CONTROLLER_OUTPUT', 'GPS_RAW' ]:
+#        print(msg)
+    idle_hook(mav)
+
 def expect_callback(e):
     '''called when waiting for a expect pattern'''
     global expect_list