commit f34ac80509272296c25de03c71763c995b1f7eb6 Author: teor teor2345@gmail.com Date: Thu Oct 2 01:58:00 2014 +1000

Check RunAsDaemon before using wait()

Avoid hangs by checking for RunAsDaemon 1 in the torrc before using wait() on a launched tor process. Iff it's absent, use poll().

A configurable poll() time is provided in env['poll_launch_time'], and a default in env['poll_launch_time_default'] is used when the torrc is unexpectedly missing RunAsDaemon 1. (TODO: We may only need one of these?) --- lib/chutney/TorNet.py | 83 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 75 insertions(+), 8 deletions(-)

diff --git a/lib/chutney/TorNet.py b/lib/chutney/TorNet.py index e4ddc7a..87f1abe 100644 --- a/lib/chutney/TorNet.py +++ b/lib/chutney/TorNet.py @@ -556,12 +556,35 @@ class LocalNodeController(NodeController): sys.exit(0) else: raise - # XXXX this requires that RunAsDaemon is set. - p.wait() - if p.returncode != 0: - print "Couldn't launch %s (%s): %s" % (self._env['nick'], - " ".join(cmdline), - p.returncode) + if self.waitOnLaunch(): + # this requires that RunAsDaemon is set + p.wait() + else: + # this does not require RunAsDaemon to be set, but is slower. + # + # poll() only catches failures before the call itself + # so let's sleep a little first + # this does, of course, slow down process launch + # which can require an adjustment to the voting interval + # + # avoid writing a newline or space when polling + # so output comes out neatly + sys.stdout.write('.') + sys.stdout.flush() + time.sleep(self._env['poll_launch_time']) + p.poll() + if p.returncode != None and p.returncode != 0: + if self._env['poll_launch_time'] is None: + print "Couldn't launch %s (%s): %s" % (self._env['nick'], + " ".join(cmdline), + p.returncode) + else: + print ("Couldn't poll %s (%s) " + "after waiting %s seconds for launch" + ": %s") % (self._env['nick'], + " ".join(cmdline), + self._env['poll_launch_time'], + p.returncode) return False return True

@@ -581,6 +604,33 @@ class LocalNodeController(NodeController): self._env['nick']) os.remove(lf)

+ def waitOnLaunch(self): + """Check whether we can wait() for the tor process to launch""" + # TODO: is this the best place for this code? + # RunAsDaemon default is 0 + runAsDaemon = False + with open(self._getTorrcFname(), 'r') as f: + for line in f.readlines(): + stline = line.strip() + # if the line isn't all whitespace or blank + if len(stline) > 0: + splline = stline.split() + # if the line has at least two tokens on it + if (len(splline) > 0 + and splline[0].lower() == "RunAsDaemon".lower() + and splline[1] == "1"): + # use the RunAsDaemon value from the torrc + # TODO: multiple values? + runAsDaemon = True + if runAsDaemon: + # we must use wait() instead of poll() + self._env['poll_launch_time'] = None + return True; + else: + # we must use poll() instead of wait() + if self._env['poll_launch_time'] is None: + self._env['poll_launch_time'] = self._env['poll_launch_time_default'] + return False;

DEFAULTS = { 'authority': False, @@ -605,6 +655,12 @@ DEFAULTS = { 'authorities': "AlternateDirAuthority bleargh bad torrc file!", 'bridges': "Bridge bleargh bad torrc file!", 'core': True, + # poll_launch_time: None means wait on launch (requires RunAsDaemon), + # otherwise, poll after that many seconds (can be fractional/decimal) + 'poll_launch_time': None, + # Used when poll_launch_time is None, but RunAsDaemon is not set + # Set low so that we don't interfere with the voting interval + 'poll_launch_time_default': 0.1, }

@@ -729,8 +785,19 @@ class Network(object): self.start()

def start(self): - print "Starting nodes" - return all([n.getController().start() for n in self._nodes]) + if self._dfltEnv['poll_launch_time'] is not None: + # format polling correctly - avoid printing a newline + sys.stdout.write("Starting nodes") + sys.stdout.flush() + else: + print "Starting nodes" + rv = all([n.getController().start() for n in self._nodes]) + # now print a newline unconditionally - this stops poll()ing + # output from being squashed together, at the cost of a blank + # line in wait()ing output + print "" + return rv +

def hup(self): print "Sending SIGHUP to nodes"