Update linux host to handle SIGHUP. use it to reload config.

remoting/tools/me2me_virtual_host.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Virtual Me2Me implementation.  This script runs and manages the processes
 # required for a Virtual Me2Me desktop, which are: X server, X desktop
 # session, and Host process.
 # This script is intended to run continuously as a background daemon
 # process, running under an ordinary (non-root) user account.
@@ skipping 631 matching lines @@
 
   for desktop in g_desktops:
     if desktop.x_proc:
       logging.info("Terminating Xvfb")
       desktop.x_proc.terminate()
 
 
 def reload_config():
   for desktop in g_desktops:
     if desktop.host_proc:
-      # Terminating the Host will cause the main loop to spawn another
-      # instance, which will read any changes made to the Host config file.
-      desktop.host_proc.terminate()
+      desktop.host_proc.send_signal(signal.SIGHUP)
 
 
 def signal_handler(signum, stackframe):
-  if signum == signal.SIGUSR1:
-    logging.info("SIGUSR1 caught, reloading configuration.")
+  if signum == signal.SIGHUP:
+    logging.info("SIGHUP caught, reloading configuration.")
     reload_config()
   else:
     # Exit cleanly so the atexit handler, cleanup(), gets called.
     raise SystemExit
 
 
 def main():
   DEFAULT_SIZE = "1280x800"
   parser = optparse.OptionParser(
       "Usage: %prog [options] [ -- [ X server options ] ]")
@@ skipping 35 matching lines @@
       print "The daemon currently is not running"
     else:
       print "Killing process %s" % pid
       os.kill(pid, signal.SIGTERM)
     return 0
 
   if options.reload:
     running, pid = PidFile(pid_filename).check()
     if not running:
       return 1
-    os.kill(pid, signal.SIGUSR1)
+    os.kill(pid, signal.SIGHUP)
     return 0
 
   if not options.size:
     options.size = [DEFAULT_SIZE]
 
   sizes = []
   for size in options.size:
     size_components = size.split("x")
     if len(size_components) != 2:
       parser.error("Incorrect size format '%s', should be WIDTHxHEIGHT" % size)
@@ skipping 65 matching lines @@
         not auth_config_loaded or not auth.has_chromoting_credentials())
     need_register_host = not host_config_loaded
     # Outside the loop so user doesn't get asked twice.
     if need_register_host:
       host.ask_pin()
     elif options.new_pin or not host.is_pin_set():
       host.ask_pin()
       host.save_config(host_config)
       running, pid = PidFile(pid_filename).check()
       if running and pid != 0:
-        os.kill(pid, signal.SIGUSR1)
+        os.kill(pid, signal.SIGHUP)
         print "The running instance has been updated with the new PIN."
         return 0
 
     # The loop is to deal with the case of registering a new Host with
     # previously-saved auth tokens (from a previous run of this script), which
     # may require re-prompting for username & password.
     while True:
       if need_auth_tokens:
         try:
           auth.generate_tokens()
@@ skipping 89 matching lines @@
         desktop.launch_x_session()
 
     if desktop.host_proc is None:
       logging.info("Launching host process")
       desktop.launch_host(host_config)
 
     try:
       pid, status = os.wait()
     except OSError, e:
       if e.errno == errno.EINTR:
-        # Retry on EINTR, which can happen if a signal such as SIGUSR1 is
+        # Retry on EINTR, which can happen if a signal such as SIGHUP is
         # received.
         continue
       else:
         # Anything else is an unexpected error.
         raise
 
     logging.info("wait() returned (%s,%s)" % (pid, status))
 
     # When os.wait() notifies that a process has terminated, any Popen instance
     # for that process is no longer valid.  Reset any affected instance to
@@ skipping 33 matching lines @@
         return 0
       elif os.WEXITSTATUS(status) == 5:
         logging.info("Host domain is blocked by policy - exiting.")
         os.remove(host.config_file)
         return 0
       # Nothing to do for Mac-only status 6 (login screen unsupported)
 
 if __name__ == "__main__":
   logging.basicConfig(level=logging.DEBUG)
   sys.exit(main())