Update floating builder logic, add to "chromiumos"

masters/master.chromiumos/master.cfg

Index: masters/master.chromiumos/master.cfg
diff --git a/masters/master.chromiumos/master.cfg b/masters/master.chromiumos/master.cfg
index 0ac68cf57b20f4168a8b6c2237a12054cc3c15c3..b6e3bb67986a88d59a34c4c7e8ff2deff407467a 100644
--- a/masters/master.chromiumos/master.cfg
+++ b/masters/master.chromiumos/master.cfg
@@ -14,6 +14,7 @@
 # dictionary has a variety of keys to control different aspects of the
 # buildmaster. They are documented in docs/config.xhtml .
 
+import datetime
 import json
 import os
 import re
@@ -24,6 +25,7 @@ from buildbot.scheduler import Periodic
 from twisted.python import log
 
 # These modules come from scripts/master, which must be in the PYTHONPATH.
+from master import floating_builder
 from master import master_utils
 from master import slaves_list
 from master.chromeos_manifest_scheduler import \
@@ -33,10 +35,11 @@ from master.cros import builder_config
 from master.factory import annotator_factory, chromeos_factory
 
 # These modules come from scripts/common, which must be in the PYTHONPATH.
-import chromiumos_board_config
+import chromiumos_board_config as board_config
 import config
 import master_site_config
 from master.cros import builder_config
+from common import slave_alloc
 from common.cros_chromite import ChromiteTarget
 
 ActiveMaster = master_site_config.ChromiumOS
@@ -68,14 +71,14 @@ factory_obj = annotator_factory.AnnotatorFactory(
 #
 
 # General source to add in cbuildbot types:
-def GenCBuild(cfg):
+def GenCBuild(bc):
   """Generate a cbuild buildbot configuration
 
       Create a buildbot builder configuration and return a builder
       dictionary associated with it.
 
     Arguments:
-      cfg: (builder_config.BuilderConfig) The config.
+      bc: (builder_config.BuilderConfig) The config.
       root_dir: Root of the directory where all work will take place.
       name: Name as displayed in the waterfall, if None generate automatically.
       branch: The branch to set the builder up for, defaults to 'master'
@@ -83,39 +86,39 @@ def GenCBuild(cfg):
       A builder dictionary assocaited with a factory
   """
   categories = ['1release full']
-  if cfg.closer:
+  if bc.closer:
     categories.append('closer')
   else:
     categories.append('info')
 
   # Give the SDK builder more time.
   factory_kwargs = {}
-  if cfg.timeout:
-    factory_kwargs['max_time'] = cfg.timeout
+  if bc.timeout:
+    factory_kwargs['max_time'] = bc.timeout
 
   properties = {
-      'cbb_config': cfg.config.name,
+      'cbb_config': bc.config.name,
   }
-  if cfg.cbb_variant:
-    properties['cbb_variant'] = cfg.cbb_variant
+  if bc.cbb_variant:
+    properties['cbb_variant'] = bc.cbb_variant
   builder = {
-      'name': str(cfg.builder_name),
-      'builddir': '%s-master' % (cfg.config.name,),
+      'name': str(bc.builder_name),
+      'builddir': '%s-master' % (bc.config.name,),
       'category': '|'.join(categories),
-      'auto_reboot': cfg.auto_reboot,
+      'auto_reboot': bc.auto_reboot,
       'factory': chromeos_factory.ChromiteRecipeFactory(
           factory_obj, 'cros/cbuildbot', **factory_kwargs),
       'properties': properties,
   }
 
-  if cfg.collapse:
+  if bc.collapse:
     builder['mergeRequests'] = builder_config.AlwaysCollapseFunc
   return builder
 
 # Associate the slaves to the builders.
 c['builders'] = []
 
-for cfg in chromiumos_board_config.builder_configs.itervalues():
+for cfg in board_config.builder_configs.itervalues():
   c['builders'].append(GenCBuild(cfg))
 
 
@@ -134,7 +137,7 @@ c['change_source'].append(CommentRespectingGitPoller(
 ####### SCHEDULERS
 
 def GetBuilders(func):
-  return [b for b in chromiumos_board_config.builder_configs.itervalues()
+  return [b for b in board_config.builder_configs.itervalues()
           if func(b)]
 
 
@@ -191,16 +194,45 @@ c['schedulers'] = [
 
 ####### BUILDSLAVES
 
+# Returns 'True' if a builder is experimental.
+def cros_builder_experimental(name):
+  config = board_config.builder_name_map.get(name)
+  return config and config.is_experimental
+
 # the 'slaves' list defines the set of allowable buildslaves. Each element is a
 # tuple of bot-name and bot-password. These correspond to values given to the
 # buildslave's mktap invocation.
 
 # First, load the list from slaves.cfg.
 slaves = slaves_list.SlavesList('slaves.cfg', 'ChromiumOS')
-if not slaves.GetSlaves():
-  raise ValueError("Failed to load slaves.")
-for builder in c['builders']:
-  builder['slavenames'] = slaves.GetSlavesName(builder=builder['name'])
+slave_map = board_config.slave_allocator.GetSlaveMap()
+
+# Assert our slave integrity and build our floating slave list.
+#
+# We will loop through every builder, identify the primary and floating slaves
+# for that builder, and set its 'nextSlave' function to our floating builder.
+slave_class_map = slave_alloc.BuildClassMap(slave_map)
+for b in c['builders']:
+  builder_name = b['name']
+  b['slavenames'] = slaves.GetSlavesName(builder=builder_name)
+  assert b['slavenames'], 'No slaves allocated for [%s]' % (builder_name,)
+
+  bc = board_config.builder_configs[builder_name]
+  if bc.floating and not cros_builder_experimental(builder_name):
+    fs = floating_builder.FloatingSet()
+
+    for slave in b['slavenames']:
+      if slave in slave_class_map.get('floating', {}).get(bc.config.category, ()):
+        fs.AddFloating(slave)
+      else:
+        fs.AddPrimary(slave)
+    b['nextSlave'] = fs.NextSlaveFunc(datetime.timedelta(minutes=15))
+
+    # Enable verbose logging.
+    # TODO(dnj): Disable when reliable.
+    b['nextSlave'].verbose = True
+    log.msg('Assigning builder [%s] to `nextSlave` function: %s' % (
+        builder_name, b['nextSlave']))
 
 # The 'slaves' list defines the set of allowable buildslaves. List all the
 # slaves registered to a builder. Remove dupes.
@@ -214,14 +246,9 @@ c['slaves'] = master_utils.AutoSetupSlaves(c['builders'],
 # Must come before AutoSetupMaster().
 c['buildbotURL'] = ActiveMaster.buildbot_url
 
-# Returns 'True' if a builder is experimental.
-def cros_builder_experimental(name):
-  config = chromiumos_board_config.builder_name_map.get(name)
-  return config and config.is_experimental
-
 # Adds common status and tools to this master.
 def cros_builder_doc(name):
-  config = chromiumos_board_config.builder_name_map.get(name)
+  config = board_config.builder_name_map.get(name)
   if config:
     doc = config.config.get('doc')
     if doc:
@@ -277,8 +304,7 @@ if ActiveMaster.is_production_host:
 if not ActiveMaster.is_production_host:
   # Save our slave pool state. This is populated when our 'slaves' variable
   # gets generated.
-  chromiumos_board_config.slave_allocator.SaveState()
-  slave_map = chromiumos_board_config.slave_allocator.GetSlaveMap()
+  board_config.slave_allocator.SaveState()
   if slave_map.unallocated:
     log.msg("The following slaves were not allocated: %s" % (
         sorted(slave_map.unallocated),))