src/nepi/core/execute.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 from nepi.core.attributes import Attribute, AttributesMap
   5 from nepi.core.connector import ConnectorTypeBase
   6 from nepi.util import proxy, validation
   7 from nepi.util.constants import STATUS_FINISHED, TIME_NOW
   8 from nepi.util.parser._xml import XmlExperimentParser
   9 import sys
  10 import re
  11 import threading
  12 import ConfigParser
  13 import os
  14
  15 ATTRIBUTE_PATTERN_BASE = re.compile(r"\{#\[(?P<label>[-a-zA-Z0-9._]*)\](?P<expr>(?P<component>\.addr\[[0-9]+\]|\.route\[[0-9]+\]|\.trace\[[0-9]+\]|).\[(?P<attribute>[-a-zA-Z0-9._]*)\])#}")
  16 ATTRIBUTE_PATTERN_GUID_SUB = r"{#[%(guid)s]%(expr)s#}"
  17 COMPONENT_PATTERN = re.compile(r"(?P<kind>[a-z]*)\[(?P<index>.*)\]")
  18
  19 class ConnectorType(ConnectorTypeBase):
  20     def __init__(self, testbed_id, factory_id, name, max = -1, min = 0):
  21         super(ConnectorType, self).__init__(testbed_id, factory_id, name, max, min)
  22         # from_connections -- connections where the other connector is the "From"
  23         # to_connections -- connections where the other connector is the "To"
  24         # keys in the dictionary correspond to the
  25         # connector_type_id for possible connections. The value is a tuple:
  26         # (can_cross, connect)
  27         # can_cross: indicates if the connection is allowed accros different
  28         #    testbed instances
  29         # code: is the connection function to be invoked when the elements
  30         #    are connected
  31         self._from_connections = dict()
  32         self._to_connections = dict()
  33
  34     def add_from_connection(self, testbed_id, factory_id, name, can_cross,
  35             init_code, compl_code):
  36         type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  37         self._from_connections[type_id] = (can_cross, init_code, compl_code)
  38
  39     def add_to_connection(self, testbed_id, factory_id, name, can_cross,
  40             init_code, compl_code):
  41         type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  42         self._to_connections[type_id] = (can_cross, init_code, compl_code)
  43
  44     def can_connect(self, testbed_id, factory_id, name, count,
  45             must_cross = False):
  46         connector_type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  47         for lookup_type_id in self._type_resolution_order(connector_type_id):
  48             if lookup_type_id in self._from_connections:
  49                 (can_cross, init_code, compl_code) = self._from_connections[lookup_type_id]
  50             elif lookup_type_id in self._to_connections:
  51                 (can_cross, init_code, compl_code) = self._to_connections[lookup_type_id]
  52             else:
  53                 # keey trying
  54                 continue
  55             return not must_cross or can_cross
  56         else:
  57             return False
  58
  59     def _connect_to_code(self, testbed_id, factory_id, name):
  60         connector_type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  61         for lookup_type_id in self._type_resolution_order(connector_type_id):
  62             if lookup_type_id in self._to_connections:
  63                 (can_cross, init_code, compl_code) = self._to_connections[lookup_type_id]
  64                 return (init_code, compl_code)
  65         else:
  66             return (False, False)
  67
  68     def connect_to_init_code(self, testbed_id, factory_id, name):
  69         return self._connect_to_code(testbed_id, factory_id, name)[0]
  70
  71     def connect_to_compl_code(self, testbed_id, factory_id, name):
  72         return self._connect_to_code(testbed_id, factory_id, name)[1]
  73
  74 class Factory(AttributesMap):
  75     def __init__(self, factory_id, create_function, start_function,
  76             stop_function, status_function,
  77             configure_function, preconfigure_function,
  78             allow_addresses = False, has_addresses = False,
  79             allow_routes = False, has_routes = False):
  80         super(Factory, self).__init__()
  81         self._factory_id = factory_id
  82         self._allow_addresses = bool(allow_addresses)
  83         self._allow_routes = bool(allow_routes)
  84         self._has_addresses = bool(has_addresses) or self._allow_addresses
  85         self._has_routes = bool(has_routes) or self._allow_routes
  86         self._create_function = create_function
  87         self._start_function = start_function
  88         self._stop_function = stop_function
  89         self._status_function = status_function
  90         self._configure_function = configure_function
  91         self._preconfigure_function = preconfigure_function
  92         self._connector_types = dict()
  93         self._traces = list()
  94         self._box_attributes = AttributesMap()
  95
  96     @property
  97     def factory_id(self):
  98         return self._factory_id
  99
 100     @property
 101     def allow_addresses(self):
 102         return self._allow_addresses
 103
 104     @property
 105     def allow_routes(self):
 106         return self._allow_routes
 107
 108     @property
 109     def has_addresses(self):
 110         return self._has_addresses
 111
 112     @property
 113     def has_routes(self):
 114         return self._has_routes
 115
 116     @property
 117     def box_attributes(self):
 118         return self._box_attributes
 119
 120     @property
 121     def create_function(self):
 122         return self._create_function
 123
 124     @property
 125     def start_function(self):
 126         return self._start_function
 127
 128     @property
 129     def stop_function(self):
 130         return self._stop_function
 131
 132     @property
 133     def status_function(self):
 134         return self._status_function
 135
 136     @property
 137     def configure_function(self):
 138         return self._configure_function
 139
 140     @property
 141     def preconfigure_function(self):
 142         return self._preconfigure_function
 143
 144     @property
 145     def traces(self):
 146         return self._traces
 147
 148     def connector_type(self, name):
 149         return self._connector_types[name]
 150
 151     def add_connector_type(self, connector_type):
 152         self._connector_types[connector_type.name] = connector_type
 153
 154     def add_trace(self, trace_id):
 155         self._traces.append(trace_id)
 156
 157     def add_box_attribute(self, name, help, type, value = None, range = None,
 158         allowed = None, flags = Attribute.NoFlags, validation_function = None):
 159         self._box_attributes.add_attribute(name, help, type, value, range,
 160                 allowed, flags, validation_function)
 161
 162 class TestbedController(object):
 163     def __init__(self, testbed_id, testbed_version):
 164         self._testbed_id = testbed_id
 165         self._testbed_version = testbed_version
 166
 167     @property
 168     def testbed_id(self):
 169         return self._testbed_id
 170
 171     @property
 172     def testbed_version(self):
 173         return self._testbed_version
 174
 175     @property
 176     def guids(self):
 177         raise NotImplementedError
 178
 179     def defer_configure(self, name, value):
 180         """Instructs setting a configuartion attribute for the testbed instance"""
 181         raise NotImplementedError
 182
 183     def defer_create(self, guid, factory_id):
 184         """Instructs creation of element """
 185         raise NotImplementedError
 186
 187     def defer_create_set(self, guid, name, value):
 188         """Instructs setting an initial attribute on an element"""
 189         raise NotImplementedError
 190
 191     def defer_factory_set(self, guid, name, value):
 192         """Instructs setting an attribute on a factory"""
 193         raise NotImplementedError
 194
 195     def defer_connect(self, guid1, connector_type_name1, guid2,
 196             connector_type_name2):
 197         """Instructs creation of a connection between the given connectors"""
 198         raise NotImplementedError
 199
 200     def defer_cross_connect(self, guid, connector_type_name, cross_guid,
 201             cross_testbed_id, cross_factory_id, cross_connector_type_name):
 202         """
 203         Instructs creation of a connection between the given connectors
 204         of different testbed instances
 205         """
 206         raise NotImplementedError
 207
 208     def defer_add_trace(self, guid, trace_id):
 209         """Instructs the addition of a trace"""
 210         raise NotImplementedError
 211
 212     def defer_add_address(self, guid, address, netprefix, broadcast):
 213         """Instructs the addition of an address"""
 214         raise NotImplementedError
 215
 216     def defer_add_route(self, guid, destination, netprefix, nexthop):
 217         """Instructs the addition of a route"""
 218         raise NotImplementedError
 219
 220     def do_setup(self):
 221         """After do_setup the testbed initial configuration is done"""
 222         raise NotImplementedError
 223
 224     def do_create(self):
 225         """
 226         After do_create all instructed elements are created and
 227         attributes setted
 228         """
 229         raise NotImplementedError
 230
 231     def do_connect_init(self):
 232         """
 233         After do_connect_init all internal connections between testbed elements
 234         are initiated
 235         """
 236         raise NotImplementedError
 237
 238     def do_connect_compl(self):
 239         """
 240         After do_connect all internal connections between testbed elements
 241         are completed
 242         """
 243         raise NotImplementedError
 244
 245     def do_configure(self):
 246         """After do_configure elements are configured"""
 247         raise NotImplementedError
 248
 249     def do_cross_connect_init(self, cross_data):
 250         """
 251         After do_cross_connect_init initiation of all external connections
 252         between different testbed elements is performed
 253         """
 254         raise NotImplementedError
 255
 256     def do_cross_connect_compl(self, cross_data):
 257         """
 258         After do_cross_connect_compl completion of all external connections
 259         between different testbed elements is performed
 260         """
 261         raise NotImplementedError
 262
 263     def start(self):
 264         raise NotImplementedError
 265
 266     def stop(self):
 267         raise NotImplementedError
 268
 269     def set(self, time, guid, name, value):
 270         raise NotImplementedError
 271
 272     def get(self, time, guid, name):
 273         raise NotImplementedError
 274
 275     def get_route(self, guid, index, attribute):
 276         """
 277         Params:
 278
 279             guid: guid of box to query
 280             index: number of routing entry to fetch
 281             attribute: one of Destination, NextHop, NetPrefix
 282         """
 283         raise NotImplementedError
 284
 285     def get_address(self, guid, index, attribute='Address'):
 286         """
 287         Params:
 288
 289             guid: guid of box to query
 290             index: number of inteface to select
 291             attribute: one of Address, NetPrefix, Broadcast
 292         """
 293         raise NotImplementedError
 294
 295     def get_attribute_list(self, guid):
 296         raise NotImplementedError
 297
 298     def action(self, time, guid, action):
 299         raise NotImplementedError
 300
 301     def status(self, guid):
 302         raise NotImplementedError
 303
 304     def trace(self, guid, trace_id, attribute='value'):
 305         raise NotImplementedError
 306
 307     def shutdown(self):
 308         raise NotImplementedError
 309
 310 class ExperimentController(object):
 311     def __init__(self, experiment_xml, root_dir):
 312         self._experiment_xml = experiment_xml
 313         self._testbeds = dict()
 314         self._access_config = dict()
 315         self._netrefs = dict()
 316         self._cross_data = dict()
 317         self._root_dir = root_dir
 318
 319         self.persist_experiment_xml()
 320
 321     @property
 322     def experiment_xml(self):
 323         return self._experiment_xml
 324
 325     def persist_experiment_xml(self):
 326         xml_path = os.path.join(self._root_dir, "experiment.xml")
 327         f = open(xml_path, "w")
 328         f.write(self._experiment_xml)
 329         f.close()
 330
 331     def set_access_configuration(self, testbed_guid, access_config):
 332         self._access_config[testbed_guid] = access_config
 333
 334     def trace(self, testbed_guid, guid, trace_id, attribute='value'):
 335         return self._testbeds[testbed_guid].trace(guid, trace_id, attribute)
 336
 337     @staticmethod
 338     def _parallel(callables):
 339         threads = [ threading.Thread(target=callable) for callable in callables ]
 340         for thread in threads:
 341             thread.start()
 342         for thread in threads:
 343             thread.join()
 344
 345     def start(self):
 346         self._init_testbed_controllers()
 347
 348         # persist testbed connection data, for potential recovery
 349         self._persist_testbed_proxies()
 350
 351         # perform setup in parallel for all test beds,
 352         # wait for all threads to finish
 353         self._parallel([testbed.do_setup
 354                         for testbed in self._testbeds.itervalues()])
 355
 356         # perform create-connect in parallel, wait
 357         # (internal connections only)
 358         self._parallel([lambda : testbed.do_create()
 359                         for testbed in self._testbeds.itervalues()])
 360
 361         # TODO! DEBUG!!!!
 362         # ONLY THE LAST TESTBED HAS ELEMENTS CREATED!!!
 363         #for testbed in self._testbeds.itervalues():
 364         #    print testbed._testbed_id
 365         #    print testbed._elements
 366
 367         self._parallel([lambda : testbed.do_connect_init()
 368                         for testbed in self._testbeds.itervalues()])
 369
 370         self._parallel([lambda : testbed.do_connect_compl()
 371                         for testbed in self._testbeds.itervalues()])
 372
 373         self._parallel([lambda : testbed.do_preconfigure()
 374                         for testbed in self._testbeds.itervalues()])
 375
 376         # resolve netrefs
 377         self.do_netrefs(fail_if_undefined=True)
 378
 379         # perform do_configure in parallel for al testbeds
 380         # (it's internal configuration for each)
 381         self._parallel([testbed.do_configure
 382                         for testbed in self._testbeds.itervalues()])
 383
 384         # cross-connect (cannot be done in parallel)
 385         for guid, testbed in self._testbeds.iteritems():
 386             cross_data = self._get_cross_data(guid)
 387             testbed.do_cross_connect_init(cross_data)
 388         for guid, testbed in self._testbeds.iteritems():
 389             cross_data = self._get_cross_data(guid)
 390             testbed.do_cross_connect_compl(cross_data)
 391
 392         # start experiment (parallel start on all testbeds)
 393         self._parallel([testbed.start
 394                         for testbed in self._testbeds.itervalues()])
 395
 396     def _persist_testbed_proxies(self):
 397         TRANSIENT = ('Recover',)
 398
 399         # persist access configuration for all testbeds, so that
 400         # recovery mode can reconnect to them if it becomes necessary
 401         conf = ConfigParser.RawConfigParser()
 402         for testbed_guid, testbed_config in self._access_config.iteritems():
 403             testbed_guid = str(testbed_guid)
 404             conf.add_section(testbed_guid)
 405             for attr in testbed_config.attributes_list:
 406                 if attr not in TRANSIENT:
 407                     conf.set(testbed_guid, attr,
 408                         testbed_config.get_attribute_value(attr))
 409
 410         f = open(os.path.join(self._root_dir, 'access_config.ini'), 'w')
 411         conf.write(f)
 412         f.close()
 413
 414     def _load_testbed_proxies(self):
 415         TYPEMAP = {
 416             STRING : 'get',
 417             INTEGER : 'getint',
 418             FLOAT : 'getfloat',
 419             BOOLEAN : 'getboolean',
 420         }
 421
 422         conf = ConfigParser.RawConfigParser()
 423         conf.read(os.path.join(self._root_dir, 'access_config.ini'))
 424         for testbed_guid in conf.sections():
 425             testbed_config = proxy.AccessConfiguration()
 426             for attr in conf.options(testbed_guid):
 427                 testbed_config.set_attribute_value(attr,
 428                     conf.get(testbed_guid, attr) )
 429
 430             testbed_guid = str(testbed_guid)
 431             conf.add_section(testbed_guid)
 432             for attr in testbed_config.attributes_list:
 433                 if attr not in TRANSIENT:
 434                     getter = getattr(conf, TYPEMAP.get(
 435                         testbed_config.get_attribute_type(attr),
 436                         'get') )
 437                     testbed_config.set_attribute_value(
 438                         testbed_guid, attr, getter(attr))
 439
 440     def _unpersist_testbed_proxies(self):
 441         try:
 442             os.remove(os.path.join(self._root_dir, 'access_config.ini'))
 443         except:
 444             # Just print exceptions, this is just cleanup
 445             import traceback
 446             traceback.print_exc(file=sys.stderr)
 447
 448     def stop(self):
 449        for testbed in self._testbeds.values():
 450            testbed.stop()
 451        self._unpersist_testbed_proxies()
 452
 453     def recover(self):
 454         # reload perviously persisted testbed access configurations
 455         self._load_testbed_proxies()
 456
 457         # recreate testbed proxies by reconnecting only
 458         self._init_testbed_controllers(recover = True)
 459
 460     def is_finished(self, guid):
 461         for testbed in self._testbeds.values():
 462             for guid_ in testbed.guids:
 463                 if guid_ == guid:
 464                     return testbed.status(guid) == STATUS_FINISHED
 465         raise RuntimeError("No element exists with guid %d" % guid)
 466
 467     def shutdown(self):
 468        for testbed in self._testbeds.values():
 469            testbed.shutdown()
 470
 471     @staticmethod
 472     def _netref_component_split(component):
 473         match = COMPONENT_PATTERN.match(component)
 474         if match:
 475             return match.group("kind"), match.group("index")
 476         else:
 477             return component, None
 478
 479     def do_netrefs(self, fail_if_undefined = False):
 480         COMPONENT_GETTERS = {
 481             'addr' :
 482                 lambda testbed, guid, index, name :
 483                     testbed.get_address(guid, index, name),
 484             'route' :
 485                 lambda testbed, guid, index, name :
 486                     testbed.get_route(guid, index, name),
 487             'trace' :
 488                 lambda testbed, guid, index, name :
 489                     testbed.trace(guid, index, name),
 490             '' :
 491                 lambda testbed, guid, index, name :
 492                     testbed.get(TIME_NOW, guid, name),
 493         }
 494
 495         for (testbed_guid, guid), attrs in self._netrefs.iteritems():
 496             testbed = self._testbeds[testbed_guid]
 497             for name in attrs:
 498                 value = testbed.get(TIME_NOW, guid, name)
 499                 if isinstance(value, basestring):
 500                     match = ATTRIBUTE_PATTERN_BASE.search(value)
 501                     if match:
 502                         label = match.group("label")
 503                         if label.startswith('GUID-'):
 504                             ref_guid = int(label[5:])
 505                             if ref_guid:
 506                                 expr = match.group("expr")
 507                                 component = match.group("component")[1:] # skip the dot
 508                                 attribute = match.group("attribute")
 509
 510                                 # split compound components into component kind and index
 511                                 # eg: 'addr[0]' -> ('addr', '0')
 512                                 component, component_index = self._netref_component_split(component)
 513
 514                                 # find object and resolve expression
 515                                 for ref_testbed in self._testbeds.itervalues():
 516                                     if component not in COMPONENT_GETTERS:
 517                                         raise ValueError, "Malformed netref: %r - unknown component" % (expr,)
 518                                     else:
 519                                         ref_value = COMPONENT_GETTERS[component](
 520                                             ref_testbed, ref_guid, component_index, attribute)
 521                                         if ref_value:
 522                                             testbed.set(TIME_NOW, guid, name,
 523                                                 value.replace(match.group(), ref_value))
 524                                             break
 525                                 else:
 526                                     # couldn't find value
 527                                     if fail_if_undefined:
 528                                         raise ValueError, "Unresolvable GUID: %r, in netref: %r" % (ref_guid, expr)
 529
 530     def _init_testbed_controllers(self, recover = False):
 531         parser = XmlExperimentParser()
 532         data = parser.from_xml_to_data(self._experiment_xml)
 533         element_guids = list()
 534         label_guids = dict()
 535         data_guids = data.guids
 536
 537         # create testbed controllers
 538         for guid in data_guids:
 539             if data.is_testbed_data(guid):
 540                 self._create_testbed_controller(guid, data, element_guids,
 541                         recover)
 542             else:
 543                 element_guids.append(guid)
 544                 label = data.get_attribute_data(guid, "label")
 545                 if label is not None:
 546                     if label in label_guids:
 547                         raise RuntimeError, "Label %r is not unique" % (label,)
 548                     label_guids[label] = guid
 549
 550         # replace references to elements labels for its guid
 551         self._resolve_labels(data, data_guids, label_guids)
 552
 553         # program testbed controllers
 554         if not recover:
 555             self._program_testbed_controllers(element_guids, data)
 556
 557     def _resolve_labels(self, data, data_guids, label_guids):
 558         netrefs = self._netrefs
 559         for guid in data_guids:
 560             if not data.is_testbed_data(guid):
 561                 for name, value in data.get_attribute_data(guid):
 562                     if isinstance(value, basestring):
 563                         match = ATTRIBUTE_PATTERN_BASE.search(value)
 564                         if match:
 565                             label = match.group("label")
 566                             if not label.startswith('GUID-'):
 567                                 ref_guid = label_guids.get(label)
 568                                 if ref_guid is not None:
 569                                     value = ATTRIBUTE_PATTERN_BASE.sub(
 570                                         ATTRIBUTE_PATTERN_GUID_SUB % dict(
 571                                             guid = 'GUID-%d' % (ref_guid,),
 572                                             expr = match.group("expr"),
 573                                             label = label),
 574                                         value)
 575                                     data.set_attribute_data(guid, name, value)
 576
 577                                     # memorize which guid-attribute pairs require
 578                                     # postprocessing, to avoid excessive controller-testbed
 579                                     # communication at configuration time
 580                                     # (which could require high-latency network I/O)
 581                                     (testbed_guid, factory_id) = data.get_box_data(guid)
 582                                     netrefs.setdefault((testbed_guid, guid), set()).add(name)
 583
 584     def _create_testbed_controller(self, guid, data, element_guids, recover):
 585         (testbed_id, testbed_version) = data.get_testbed_data(guid)
 586         access_config = None if guid not in self._access_config else\
 587                 self._access_config[guid]
 588
 589         if recover and access_config is None:
 590             # need to create one
 591             access_config = self._access_config[guid] = proxy.AccessConfiguration()
 592         if access_config is not None:
 593             # force recovery mode
 594             access_config.set_attribute_value("recover",recover)
 595
 596         testbed = proxy.create_testbed_controller(testbed_id,
 597                 testbed_version, access_config)
 598         for (name, value) in data.get_attribute_data(guid):
 599             testbed.defer_configure(name, value)
 600         self._testbeds[guid] = testbed
 601
 602     def _program_testbed_controllers(self, element_guids, data):
 603         for guid in element_guids:
 604             (testbed_guid, factory_id) = data.get_box_data(guid)
 605             testbed = self._testbeds[testbed_guid]
 606             testbed.defer_create(guid, factory_id)
 607             for (name, value) in data.get_attribute_data(guid):
 608                 testbed.defer_create_set(guid, name, value)
 609
 610         for guid in element_guids:
 611             (testbed_guid, factory_id) = data.get_box_data(guid)
 612             testbed = self._testbeds[testbed_guid]
 613             for (connector_type_name, cross_guid, cross_connector_type_name) \
 614                     in data.get_connection_data(guid):
 615                 (testbed_guid, factory_id) = data.get_box_data(guid)
 616                 (cross_testbed_guid, cross_factory_id) = data.get_box_data(
 617                         cross_guid)
 618                 if testbed_guid == cross_testbed_guid:
 619                     testbed.defer_connect(guid, connector_type_name,
 620                             cross_guid, cross_connector_type_name)
 621                 else:
 622                     cross_testbed = self._testbeds[cross_testbed_guid]
 623                     cross_testbed_id = cross_testbed.testbed_id
 624                     testbed.defer_cross_connect(guid, connector_type_name, cross_guid,
 625                             cross_testbed_id, cross_factory_id,
 626                             cross_connector_type_name)
 627                     # save cross data for later
 628                     self._add_crossdata(testbed_guid, guid, cross_testbed_guid,
 629                             cross_guid)
 630             for trace_id in data.get_trace_data(guid):
 631                 testbed.defer_add_trace(guid, trace_id)
 632             for (autoconf, address, netprefix, broadcast) in \
 633                     data.get_address_data(guid):
 634                 if address != None:
 635                     testbed.defer_add_address(guid, address, netprefix,
 636                             broadcast)
 637             for (destination, netprefix, nexthop) in data.get_route_data(guid):
 638                 testbed.defer_add_route(guid, destination, netprefix, nexthop)
 639
 640     def _add_crossdata(self, testbed_guid, guid, cross_testbed_guid, cross_guid):
 641         if testbed_guid not in self._cross_data:
 642             self._cross_data[testbed_guid] = dict()
 643         if cross_testbed_guid not in self._cross_data[testbed_guid]:
 644             self._cross_data[testbed_guid][cross_testbed_guid] = list()
 645         if cross_testbed_guid not in self._cross_data:
 646             self._cross_data[cross_testbed_guid] = dict()
 647         if testbed_guid not in self._cross_data[cross_testbed_guid]:
 648             self._cross_data[cross_testbed_guid][testbed_guid] = list()
 649         self._cross_data[testbed_guid][cross_testbed_guid].append(cross_guid)
 650         self._cross_data[cross_testbed_guid][testbed_guid].append(guid)
 651
 652     def _get_cross_data(self, testbed_guid):
 653         cross_data = dict()
 654         if not testbed_guid in self._cross_data:
 655             return cross_data
 656         for cross_testbed_guid, guid_list in \
 657                 self._cross_data[testbed_guid].iteritems():
 658             cross_data[cross_testbed_guid] = dict()
 659             cross_testbed = self._testbeds[cross_testbed_guid]
 660             for cross_guid in guid_list:
 661                 elem_cross_data = dict()
 662                 cross_data[cross_testbed_guid][cross_guid] = elem_cross_data
 663                 attributes_list = cross_testbed.get_attribute_list(cross_guid)
 664                 for attr_name in attributes_list:
 665                     attr_value = cross_testbed.get(TIME_NOW, cross_guid,
 666                             attr_name)
 667                     elem_cross_data[attr_name] = attr_value
 668         return elem_cross_data
 669