Log when leaving main and list remaining threads in builder_alerts

infra/services/builder_alerts/alert_builder.py

 # Copyright 2014 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.
 import argparse
 import json
 import logging
 import multiprocessing
 import os
 import re
 import sys
@@ skipping 355 matching lines @@
       return alerts_for_builder(cache, master_url, builder_name,
                                 recent_build_ids, old_alerts)
     except:
       # Put all exception text into an exception and raise that so it doesn't
       # get eaten by the multiprocessing code.
       raise Exception(''.join(traceback.format_exception(*sys.exc_info())))
     finally:
       logging.debug('Thread for builder %s has finished', builder_name)
 
   pool = multiprocessing.dummy.Pool(processes=jobs)
-  logging.debug('Processing all threads via thread pool')
+  logging.debug('Processing all builders via thread pool')
   builder_alerts = pool.map(process_builder, master_json['builders'].keys())
-  logging.debug('Closing all threads in thread pool')
+  logging.debug('Closing all threads in builder thread pool')
   pool.close()
   pool.join()
-  logging.debug('Joined all threads in thread pool')
+  logging.debug('Joined all threads in builder thread pool')
 
   alerts = []
   for alert in builder_alerts:
     if alert:
       alerts.extend(alert)
 
+  logging.debug('Computing alerts_for_stale_master_data')
   stale_master_data_alert = alert_for_stale_master_data(master_url, master_json)
+  logging.debug('Finished alerts_for_master')
   return (alerts, stale_master_data_alert)
 
 
 def main(args):  # pragma: no cover
   logging.basicConfig(level=logging.DEBUG)
 
   parser = argparse.ArgumentParser()
   parser.add_argument('builder_url', action='store')
   args = parser.parse_args(args)
 
   # https://build.chromium.org/p/chromium.win/builders/XP%20Tests%20(1)
   url_regexp = re.compile('(?P<master_url>.*)/builders/(?P<builder_name>.*)/?')
   match = url_regexp.match(args.builder_url)
 
   # FIXME: HACK
   CACHE_PATH = 'build_cache'
   cache = buildbot.DiskCache(CACHE_PATH)
 
   master_url = match.group('master_url')
   builder_name = urllib.unquote_plus(match.group('builder_name'))
   master_json = buildbot.fetch_master_json(master_url)
   # This is kinda a hack, but uses more of our existing code this way:
   alerts = alerts_for_master(cache, master_url, master_json, builder_name)
   print json.dumps(alerts[0], indent=1)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))