double wait does not work, blocking in signal handler not good, exit …

…on do_exit, change to SIGINT, use existing stop to support ctrl+c

selfdrive/pandad/pandad.py

@@ -67,20 +67,21 @@ def main() -> NoReturn:
   # signal pandad to close the relay and exit
   def signal_handler(signum, frame):
     cloudlog.info(f"Caught signal {signum}, exiting")
-    if process is not None and process.poll() is None:
-      process.terminate()
-      process.wait()
-    sys.exit(1)
+    nonlocal do_exit
+    do_exit = True
+    if process is not None:
+      process.send_signal(signal.SIGINT)
 
   process = None
-  signal.signal(signal.SIGTERM, signal_handler)
+  signal.signal(signal.SIGINT, signal_handler)
 
   count = 0
+  do_exit = False
   first_run = True
   params = Params()
   no_internal_panda_count = 0
 
-  while True:
+  while not do_exit:
     try:
       count += 1
       cloudlog.event("pandad.flash_and_connect", count=count)

system/manager/manager.py

@@ -172,10 +172,6 @@ def manager_thread() -> None:
         cloudlog.warning(f"Shutting down manager - {param} set")
 
     if shutdown:
-      # Signal processes to shut down with a small grace period
-      for p in managed_processes.values():
-        p.signal(signal.SIGTERM)
-      time.sleep(1)
       break