Floating builder logic waits at startup.

scripts/master/floating_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 itertools
 from datetime import datetime
 
 from twisted.python import log
 from twisted.internet import reactor
 
 
 class FloatingSet(object):
   """A set describing available primary/floating slaves."""
   def __init__(self):
     self._primary = set()
@@ skipping 71 matching lines @@
   Args:
     fs (FloatingSet): The set of available primary/floating slaves.
     grace_period: (timedelta) The amount of time that a slave can be offline
         before builds fall through to a lower strata.
   """
 
   def __init__(self, fs, grace_period):
     self._primary, self._floating = fs.Get()
     self._fs = fs
     self._grace_period = grace_period
-    self._slave_seen_times = {}
     self._poke_builder_timers = {}
     self.verbose = False
 
+    started = _get_now()
+    self._slave_seen_times = dict((s, started) for s in itertools.chain(
+        self._primary, self._floating))
+
   def __repr__(self):
     return '%s(%s)' % (type(self).__name__, self._fs)
 
   def __call__(self, builder, slave_builders):
     """Main 'nextSlave' invocation point.
 
     When this is called, we are given the following information:
     - The Builder
     - A set of 'SlaveBuilder' instances that are available and ready for
       assignment (slave_builders).
@@ skipping 67 matching lines @@
 
       # Is this slave online? If so, we won't consider floating candiates.
       if slave_name in online_slave_builders:
         # The slave is online, but is not proposed (BUSY); add it to the
         # desired slaves list.
         self._debug('Slave [%s] is online but BUSY.', slave_name)
         within_grace_period.append(slave_name)
         some_primary_were_busy = True
         continue
 
-      # Get the 'SlaveStatus' object for this slave
+      # The slave is offline. Is this slave within the grace period?
       slave_status = slave_status_map.get(slave_name)
-      if slave_status is None:
-        continue
-
-      # The slave is offline. Is this slave within the grace period?
-      last_seen = self._get_latest_seen_time(slave_status)
+      last_seen = self._get_latest_seen_time(slave_name, slave_status)
       if last_seen < grace_threshold:
         # No, the slave is older than our grace period.
         self._debug('Slave [%s] is OFFLINE and outside grace period '
                     '(%s < %s).', slave_name, last_seen, grace_threshold)
         continue
 
       # This slave is within its grace threshold. Add it to the list of
       # desired slaves from this set and update our wait delta in case we
       # have to poke.
       #
@@ skipping 43 matching lines @@
   @staticmethod
   def _get_all_slave_status(builder):
     # Try using the builder's BuilderStatus object to get a list of all slaves
     if builder.builder_status is not None:
       return builder.builder_status.getSlaves()
 
     # Satisfy with the list of currently-connected slaves
     return [slave_builder.slave.slave_status
             for slave_builder in builder.slaves]
 
-  def _get_latest_seen_time(self, slave_status):
-    times = []
+  def _get_latest_seen_time(self, slave_name, slave_status):
+    times = [self._slave_seen_times[slave_name]]
 
-    # Add all of the registered connect times
-    times += [datetime.fromtimestamp(connect_time)
-              for connect_time in slave_status.connect_times]
+    if slave_status:
+      # Add all of the registered connect times
+      times += [datetime.fromtimestamp(connect_time)
+                for connect_time in slave_status.connect_times]
 
-    # Add the time of the slave's last message
-    times.append(datetime.fromtimestamp(slave_status.lastMessageReceived()))
+      # Add the time of the slave's last message
+      times.append(datetime.fromtimestamp(slave_status.lastMessageReceived()))
 
-    # Add the last time we've seen the slave in our 'nextSlave' function
-    last_seen_time = self._slave_seen_times.get(slave_status.name)
-    if last_seen_time is not None:
-      times.append(last_seen_time)
-
-    if not times:
-      return None
     return max(times)
 
   def _record_slave_seen_time(self, build_slave, now):
     self._slave_seen_times[build_slave.slavename] = now
 
   def _schedule_builder_timer(self, builder, delta):
     poke_builder_timer = self._poke_builder_timers.get(builder.name)
     if poke_builder_timer is None:
       poke_builder_timer = PokeBuilderTimer(
           builder.botmaster,
           builder.name,
       )
       self._poke_builder_timers[builder.name] = poke_builder_timer
     poke_builder_timer.reset(delta)
 
   def _cancel_builder_timer(self, builder):
     poke_builder_timer = self._poke_builder_timers.get(builder.name)
     if poke_builder_timer is None:
       return
     poke_builder_timer.cancel()
 
 
 def _get_now():
   """Returns (datetime.datetime): The current time.
 
   This exists so it can be overridden by mocks in unit tests.
   """
   return datetime.now()