ActivityTool.py

##############################################################################
#
# Copyright (c) 2002 Nexedi SARL and Contributors. All Rights Reserved.
#                    Jean-Paul Smets-Solanes <jp@nexedi.com>
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsability of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# garantees and support are strongly adviced to contract a Free Software
# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
##############################################################################

import socket
import urllib
import threading
import sys
from types import StringType
import re

from Products.CMFCore import CMFCorePermissions
from Products.ERP5Type.Core.Folder import Folder
from Products.CMFActivity.ActiveResult import ActiveResult
from Products.PythonScripts.Utility import allow_class
from AccessControl import ClassSecurityInfo, Permissions
from AccessControl.SecurityManagement import newSecurityManager
from AccessControl.SecurityManagement import noSecurityManager
from AccessControl.SecurityManagement import setSecurityManager
from AccessControl.SecurityManagement import getSecurityManager
from Products.CMFCore.utils import UniqueObject, _getAuthenticatedUser, getToolByName
from Globals import InitializeClass, DTMLFile
from Acquisition import aq_base
from Acquisition import aq_inner
from ActivityBuffer import ActivityBuffer
from zExceptions import ExceptionFormatter
from BTrees.OIBTree import OIBTree
from Products import iHotfix

from ZODB.POSException import ConflictError
from Products.MailHost.MailHost import MailHostError

from zLOG import LOG, INFO, WARNING, ERROR
from warnings import warn

try:
  from Products.TimerService import getTimerService
except ImportError:
  def getTimerService(self):
    pass

# minimal IP:Port regexp
NODE_RE = re.compile('^\d+\.\d+\.\d+\.\d+:\d+$')

# Using a RAM property (not a property of an instance) allows
# to prevent from storing a state in the ZODB (and allows to restart...)
active_threads = 0
max_active_threads = 1 # 2 will cause more bug to appear (he he)
is_initialized = False
tic_lock = threading.Lock() # A RAM based lock to prevent too many concurrent tic() calls
timerservice_lock = threading.Lock() # A RAM based lock to prevent TimerService spamming when busy
first_run = True
currentNode = None
ROLE_IDLE = 0
ROLE_PROCESSING = 1

# Activity Registration
activity_dict = {}

logging = False

def enableLogging():
  global logging
  logging = True

def disableLogging():
  global logging
  logging = False

# Here go ActivityBuffer instances
# Structure:
#  global_activity_buffer[activity_tool_path][thread_id] = ActivityBuffer
global_activity_buffer = {}
from thread import get_ident, allocate_lock
global_activity_buffer_lock = allocate_lock()

def registerActivity(activity):
  # Must be rewritten to register
  # class and create instance for each activity
  #LOG('Init Activity', 0, str(activity.__name__))
  activity_instance = activity()
  activity_dict[activity.__name__] = activity_instance

MESSAGE_NOT_EXECUTED = 0
MESSAGE_EXECUTED = 1
MESSAGE_NOT_EXECUTABLE = 2

class Message:
  """Activity Message Class.

  Message instances are stored in an activity queue, inside the Activity Tool.
  """
  def __init__(self, obj, active_process, activity_kw, method_id, args, kw):
    if isinstance(obj, str):
      self.object_path = tuple(obj.split('/'))
    else:
      self.object_path = obj.getPhysicalPath()
    if type(active_process) is StringType:
      self.active_process = active_process.split('/')
    elif active_process is None:
      self.active_process = None
    else:
      self.active_process = active_process.getPhysicalPath()
      self.active_process_uid = active_process.getUid()
    if activity_kw.get('serialization_tag', False) is None:
      # Remove serialization_tag if it's None.
      del activity_kw['serialization_tag']
    self.activity_kw = activity_kw
    self.method_id = method_id
    self.args = args
    self.kw = kw
    self.is_executed = MESSAGE_NOT_EXECUTED
    self.exc_type = None
    self.exc_value = None
    self.traceback = None
    self.processing = None
    self.user_name = str(_getAuthenticatedUser(self))
    # Store REQUEST Info
    request = getattr(obj, 'REQUEST', None)
    if request is not None:
      self.request_info = dict(
        SERVER_URL=request.other['SERVER_URL'],
        VirtualRootPhysicalPath=request.other.get('VirtualRootPhysicalPath'),
        HTTP_ACCEPT_LANGUAGE=request.environ.get('HTTP_ACCEPT_LANGUAGE'),
        _script=list(request._script))

  def getObject(self, activity_tool):
    """return the object referenced in this message."""
    return activity_tool.unrestrictedTraverse(self.object_path)

  def getObjectList(self, activity_tool):
    """return the list of object that can be expanded from this message."""
    object_list = []
    try:
      object_list.append(self.getObject(activity_tool))
    except KeyError:
      pass
    else:
      if self.hasExpandMethod():
        expand_method_id = self.activity_kw['expand_method_id']
        # FIXME: how to pass parameters?
        object_list = getattr(object_list[0], expand_method_id)()
    return object_list

  def hasExpandMethod(self):
    """return true if the message has an expand method.
    An expand method is used to expand the list of objects and to turn a
    big recursive transaction affecting many objects into multiple
    transactions affecting only one object at a time (this can prevent
    duplicated method calls)."""
    return self.activity_kw.has_key('expand_method_id')

  def changeUser(self, user_name, activity_tool):
    """restore the security context for the calling user."""
    uf = activity_tool.getPortalObject().acl_users
    user = uf.getUserById(user_name)
    # if the user is not found, try to get it from a parent acl_users
    # XXX this is still far from perfect, because we need to store all
    # informations about the user (like original user folder, roles) to
    # replay the activity with exactly the same security context as if
    # it had been executed without activity.
    if user is None:
      uf = activity_tool.getPortalObject().aq_parent.acl_users
      user = uf.getUserById(user_name)
    if user is not None:
      user = user.__of__(uf)
      newSecurityManager(None, user)
    else :
      LOG("CMFActivity", WARNING,
          "Unable to find user %s in the portal" % user_name)
      noSecurityManager()
    return user

  def activateResult(self, activity_tool, result, object):
    if self.active_process is not None:
      active_process = activity_tool.unrestrictedTraverse(self.active_process)
      if isinstance(result, ActiveResult):
        result.edit(object_path=object)
        result.edit(method_id=self.method_id)
        # XXX Allow other method_id in future
        active_process.activateResult(result)
      else:
        active_process.activateResult(
                    ActiveResult(object_path=object,
                                 method_id=self.method_id,
                                 result=result)) # XXX Allow other method_id in future

  def __call__(self, activity_tool):
    try:
      obj = self.getObject(activity_tool)
    except KeyError:
      self.is_executed = MESSAGE_NOT_EXECUTABLE
    else:
      try:
        old_security_manager = getSecurityManager()
        # Change user if required (TO BE DONE)
        # We will change the user only in order to execute this method
        user = self.changeUser(self.user_name, activity_tool)
        # XXX: There is no check to see if user is allowed to access
        # that method !
        method = getattr(obj, self.method_id, None)
        try:
          if method is None:
            self.is_executed = MESSAGE_NOT_EXECUTABLE
          else:
            result = method(*self.args, **self.kw)
        finally:
          setSecurityManager(old_security_manager)

        if method is not None:
          self.activateResult(activity_tool, result, obj)
          self.is_executed = MESSAGE_EXECUTED
      except:
        self.is_executed = MESSAGE_NOT_EXECUTED
        exc_info = sys.exc_info()
        self.exc_type = exc_info[0]
        self.exc_value = str(exc_info[1])
        self.traceback = ''.join(ExceptionFormatter.format_exception(
                                 *exc_info))
        LOG('ActivityTool', WARNING,
            'Could not call method %s on object %s' % (
            self.method_id, self.object_path), error=exc_info)
        # push the error in ZODB error_log
        if getattr(activity_tool, 'error_log', None) is not None:
          activity_tool.error_log.raising(exc_info)

  def validate(self, activity, activity_tool, check_order_validation=1):
    return activity.validate(activity_tool, self,
                             check_order_validation=check_order_validation,
                             **self.activity_kw)

  def getDependentMessageList(self, activity, activity_tool):
    return activity.getDependentMessageList(activity_tool, self, **self.activity_kw)

  def notifyUser(self, activity_tool, message="Failed Processing Activity"):
    """Notify the user that the activity failed."""
    portal = activity_tool.getPortalObject()
    user_email = portal.getProperty('email_to_address',
                       portal.getProperty('email_from_address'))
    mail_text = """From: %s
To: %s
Subject: %s

%s

Document: %s
Method: %s
Exception: %s %s

%s
""" % (activity_tool.email_from_address, user_email, message,
       message, '/'.join(self.object_path), self.method_id,
       self.exc_type, self.exc_value, self.traceback)
    try:
      activity_tool.MailHost.send( mail_text )
    except (socket.error, MailHostError), message:
      LOG('ActivityTool.notifyUser', WARNING, 'Mail containing failure information failed to be sent: %s. Exception was: %s %s\n%s' % (message, self.exc_type, self.exc_value, self.traceback))

  def reactivate(self, activity_tool):
    # Reactivate the original object.
    obj= self.getObject(activity_tool)
    # Change user if required (TO BE DONE)
    # We will change the user only in order to execute this method
    current_user = str(_getAuthenticatedUser(self))
    user = self.changeUser(self.user_name, activity_tool)
    try:
      active_obj = obj.activate(**self.activity_kw)
      getattr(active_obj, self.method_id)(*self.args, **self.kw)
    finally:
      # Use again the previous user
      if user is not None:
        self.changeUser(current_user, activity_tool)

class Method:

  def __init__(self, passive_self, activity, active_process, kw, method_id):
    self.__passive_self = passive_self
    self.__activity = activity
    self.__active_process = active_process
    self.__kw = kw
    self.__method_id = method_id

  def __call__(self, *args, **kw):
    m = Message(self.__passive_self, self.__active_process, self.__kw, self.__method_id, args, kw)
    if logging:
      LOG('Activity Tracking', INFO, 'queuing message: activity=%s, object_path=%s, method_id=%s, args=%s, kw=%s, activity_kw=%s, user_name=%s' % (self.__activity, '/'.join(m.object_path), m.method_id, m.args, m.kw, m.activity_kw, m.user_name))
    activity_dict[self.__activity].queueMessage(self.__passive_self.portal_activities, m)

allow_class(Method)

class ActiveWrapper:

  def __init__(self, passive_self, activity, active_process, **kw):
    self.__dict__['__passive_self'] = passive_self
    self.__dict__['__activity'] = activity
    self.__dict__['__active_process'] = active_process
    self.__dict__['__kw'] = kw

  def __getattr__(self, id):
    return Method(self.__dict__['__passive_self'], self.__dict__['__activity'],
                  self.__dict__['__active_process'],
                  self.__dict__['__kw'], id)

class ActivityTool (Folder, UniqueObject):
    """
    ActivityTool is the central point for activity management.

    Improvement to consider to reduce locks:

      Idea 1: create an SQL tool which accumulate queries and executes them at the end of a transaction,
              thus allowing all SQL transaction to happen in a very short time
              (this would also be a great way of using MyISAM tables)

      Idea 2: do the same at the level of ActivityTool

      Idea 3: do the same at the level of each activity (ie. queueMessage
              accumulates and fires messages at the end of the transactino)
    """
    id = 'portal_activities'
    meta_type = 'CMF Activity Tool'
    portal_type = 'Activity Tool'
    allowed_types = ( 'CMF Active Process', )
    security = ClassSecurityInfo()

    manage_options = tuple(
                     [ { 'label' : 'Overview', 'action' : 'manage_overview' }
                     , { 'label' : 'Activities', 'action' : 'manageActivities' }
                     , { 'label' : 'LoadBalancing', 'action' : 'manageLoadBalancing'}
                     , { 'label' : 'Advanced', 'action' : 'manageActivitiesAdvanced' }
                     ,
                     ] + list(Folder.manage_options))

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageActivities' )
    manageActivities = DTMLFile( 'dtml/manageActivities', globals() )

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageActivitiesAdvanced' )
    manageActivitiesAdvanced = DTMLFile( 'dtml/manageActivitiesAdvanced', globals() )

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manage_overview' )
    manage_overview = DTMLFile( 'dtml/explainActivityTool', globals() )
    
    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageLoadBalancing' )
    manageLoadBalancing = DTMLFile( 'dtml/manageLoadBalancing', globals() )
    
    distributingNode = ''
    _nodes = ()

    def __init__(self):
        return Folder.__init__(self, ActivityTool.id)

    # Filter content (ZMI))
    def filtered_meta_types(self, user=None):
        # Filters the list of available meta types.
        all = ActivityTool.inheritedAttribute('filtered_meta_types')(self)
        meta_types = []
        for meta_type in self.all_meta_types():
            if meta_type['name'] in self.allowed_types:
                meta_types.append(meta_type)
        return meta_types

    def initialize(self):
      global is_initialized
      from Activity import RAMQueue, RAMDict, SQLQueue, SQLDict
      # Initialize each queue
      for activity in activity_dict.itervalues():
        activity.initialize(self)
      is_initialized = True
      
    security.declareProtected(Permissions.manage_properties, 'isSubscribed')
    def isSubscribed(self):
        """
        return True, if we are subscribed to TimerService.
        Otherwise return False.
        """
        service = getTimerService(self)
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            return False
        
        path = '/'.join(self.getPhysicalPath())
        if path in service.lisSubscriptions():
            return True
        return False

    security.declareProtected(Permissions.manage_properties, 'subscribe')
    def subscribe(self, REQUEST=None, RESPONSE=None):
        """ subscribe to the global Timer Service """
        service = getTimerService(self)
        url = '%s/manageLoadBalancing?manage_tabs_message=' %self.absolute_url()
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            url += urllib.quote('TimerService not available')
        else:
            service.subscribe(self)
            url += urllib.quote("Subscribed to Timer Service")
        if RESPONSE is not None:
            RESPONSE.redirect(url)

    security.declareProtected(Permissions.manage_properties, 'unsubscribe')
    def unsubscribe(self, REQUEST=None, RESPONSE=None):
        """ unsubscribe from the global Timer Service """
        service = getTimerService(self)
        url = '%s/manageLoadBalancing?manage_tabs_message=' %self.absolute_url()
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            url += urllib.quote('TimerService not available')
        else:
            service.unsubscribe(self)
            url += urllib.quote("Unsubscribed from Timer Service")
        if RESPONSE is not None:
            RESPONSE.redirect(url)

    def manage_beforeDelete(self, item, container):
        self.unsubscribe()
        Folder.inheritedAttribute('manage_beforeDelete')(self, item, container)
    
    def manage_afterAdd(self, item, container):
        self.subscribe()
        Folder.inheritedAttribute('manage_afterAdd')(self, item, container)
       
    def getCurrentNode(self):
        """ Return current node in form ip:port """
        global currentNode
        if currentNode is None:
          port = ''
          from asyncore import socket_map
          for k, v in socket_map.items():
              if hasattr(v, 'port'):
                  # see Zope/lib/python/App/ApplicationManager.py: def getServers(self)
                  type = str(getattr(v, '__class__', 'unknown'))
                  if type == 'ZServer.HTTPServer.zhttp_server':
                      port = v.port
                      break
          ip = socket.gethostbyname(socket.gethostname())
          currentNode = '%s:%s' %(ip, port)
        return currentNode
        
    security.declarePublic('getDistributingNode')
    def getDistributingNode(self):
        """ Return the distributingNode """
        return self.distributingNode

    def getNodeList(self, role=None):
      node_dict = self.getNodeDict()
      if role is None:
        result = [x for x in node_dict.keys()]
      else:
        result = [node_id for node_id, node_role in node_dict.items() if node_role == role]
      result.sort()
      return result

    def getNodeDict(self):
      nodes = self._nodes
      if isinstance(nodes, tuple):
        new_nodes = OIBTree()
        new_nodes.update([(x, ROLE_PROCESSING) for x in self._nodes])
        self._nodes = nodes = new_nodes
      return nodes

    def registerNode(self, node):
      node_dict = self.getNodeDict()
      if not node_dict.has_key(node):
        if len(node_dict) == 0: # If we are registering the first node, make
                                # it both the distributing node and a processing
                                # node.
          role = ROLE_PROCESSING
          self.distributingNode = node
        else:
          role = ROLE_IDLE
        self.updateNode(node, role)

    def updateNode(self, node, role):
      node_dict = self.getNodeDict()
      node_dict[node] = role

    security.declareProtected(CMFCorePermissions.ManagePortal, 'getProcessingNodeList')
    def getProcessingNodeList(self):
      return self.getNodeList(role=ROLE_PROCESSING)

    security.declareProtected(CMFCorePermissions.ManagePortal, 'getIdleNodeList')
    def getIdleNodeList(self):
      return self.getNodeList(role=ROLE_IDLE)

    def _isValidNodeName(self, node_name) :
      """Check we have been provided a good node name"""
      return isinstance(node_name, str) and NODE_RE.match(node_name)
      
    security.declarePublic('manage_setDistributingNode')
    def manage_setDistributingNode(self, distributingNode, REQUEST=None):
        """ set the distributing node """   
        if not distributingNode or self._isValidNodeName(distributingNode):
          self.distributingNode = distributingNode
          if REQUEST is not None:
              REQUEST.RESPONSE.redirect(
                  REQUEST.URL1 +
                  '/manageLoadBalancing?manage_tabs_message=' +
                  urllib.quote("Distributing Node successfully changed."))
        else :
          if REQUEST is not None:
              REQUEST.RESPONSE.redirect(
                  REQUEST.URL1 +
                  '/manageLoadBalancing?manage_tabs_message=' +
                  urllib.quote("Malformed Distributing Node."))

    security.declareProtected(CMFCorePermissions.ManagePortal, 'manage_delNode')
    def manage_delNode(self, unused_node_list=None, REQUEST=None):
      """ delete selected unused nodes """
      processing_node = self.getDistributingNode()
      updated_processing_node = False
      if unused_node_list is not None:
        node_dict = self.getNodeDict()
        for node in unused_node_list:
          if node in node_dict:
            del node_dict[node]
          if node == processing_node:
            self.processing_node = ''
            updated_processing_node = True
      if REQUEST is not None:
        if unused_node_list is None:
          message = "No unused node selected, nothing deleted."
        else:
          message = "Deleted nodes %r." % (unused_node_list, )
        if updated_processing_node:
          message += "Disabled distributing node because it was deleted."
        REQUEST.RESPONSE.redirect(
          REQUEST.URL1 +
          '/manageLoadBalancing?manage_tabs_message=' +
          urllib.quote(message))

    security.declareProtected(CMFCorePermissions.ManagePortal, 'manage_addToProcessingList')
    def manage_addToProcessingList(self, unused_node_list=None, REQUEST=None):
      """ Change one or more idle nodes into processing nodes """
      if unused_node_list is not None:
        node_dict = self.getNodeDict()
        for node in unused_node_list:
          self.updateNode(node, ROLE_PROCESSING)
      if REQUEST is not None:
        if unused_node_list is None:
          message = "No unused node selected, nothing done."
        else:
          message = "Nodes now procesing: %r." % (unused_node_list, )
        REQUEST.RESPONSE.redirect(
          REQUEST.URL1 +
          '/manageLoadBalancing?manage_tabs_message=' +
          urllib.quote(message))

    security.declareProtected(CMFCorePermissions.ManagePortal, 'manage_removeFromProcessingList')
    def manage_removeFromProcessingList(self, processing_node_list=None, REQUEST=None):
      """ Change one or more procesing nodes into idle nodes """
      if processing_node_list is not None:
        node_dict = self.getNodeDict()
        for node in processing_node_list:
          self.updateNode(node, ROLE_IDLE)
      if REQUEST is not None:
        if processing_node_list is None:
          message = "No used node selected, nothing done."
        else:
          message = "Nodes now unused %r." % (processing_node_list, )
        REQUEST.RESPONSE.redirect(
          REQUEST.URL1 +
          '/manageLoadBalancing?manage_tabs_message=' +
          urllib.quote(message))

    def process_timer(self, tick, interval, prev="", next=""):
        """
        Call distribute() if we are the Distributing Node and call tic()
        with our node number.
        This method is called by TimerService in the interval given
        in zope.conf. The Default is every 5 seconds.
        """
        # Prevent TimerService from starting multiple threads in parallel
        acquired = timerservice_lock.acquire(0)
        if not acquired:
          return

        try:
          old_sm = getSecurityManager()
          try:
            try:
              # get owner of portal_catalog, so normally we should be able to
              # have the permission to invoke all activities
              user = self.portal_catalog.getWrappedOwner()
              newSecurityManager(self.REQUEST, user)

              currentNode = self.getCurrentNode()
              self.registerNode(currentNode)
              processing_node_list = self.getNodeList(role=ROLE_PROCESSING)

              # only distribute when we are the distributingNode or if it's empty
              if (self.getDistributingNode() == currentNode):
                self.distribute(len(processing_node_list))

              # SkinsTool uses a REQUEST cache to store skin objects, as
              # with TimerService we have the same REQUEST over multiple
              # portals, we clear this cache to make sure the cache doesn't
              # contains skins from another portal.
              stool = getToolByName(self, 'portal_skins', None)
              if stool is not None:
                stool.changeSkin(None)

              # call tic for the current processing_node
              # the processing_node numbers are the indices of the elements in the node tuple +1
              # because processing_node starts form 1
              if currentNode in processing_node_list:
                self.tic(processing_node_list.index(currentNode)+1)
            except:
              # Catch ALL exception to avoid killing timerserver.
              LOG('ActivityTool', ERROR, 'process_timer received an exception', error=sys.exc_info())
          finally:
            setSecurityManager(old_sm)
        finally:
          timerservice_lock.release()

    security.declarePublic('distribute')
    def distribute(self, node_count=1):
      """
        Distribute load
      """
      # Initialize if needed
      if not is_initialized:
        self.initialize()

      # Call distribute on each queue
      for activity in activity_dict.itervalues():
        activity.distribute(aq_inner(self), node_count)

    security.declarePublic('tic')
    def tic(self, processing_node=1, force=0):
      """
        Starts again an activity
        processing_node starts from 1 (there is not node 0)
      """
      global active_threads, first_run

      # return if the number of threads is too high
      # else, increase the number of active_threads and continue
      tic_lock.acquire()
      too_many_threads = (active_threads >= max_active_threads)
      if not too_many_threads or force:
        active_threads += 1
      else:
        tic_lock.release()
        raise RuntimeError, 'Too many threads'
      tic_lock.release()

      # Initialize if needed
      if not is_initialized:
        self.initialize()

      inner_self = aq_inner(self)

      # If this is the first tic after zope is started, reset the processing
      # flag for activities of this node
      if first_run:
        inner_self.SQLDict_clearProcessingFlag(
                                processing_node=processing_node)
        inner_self.SQLQueue_clearProcessingFlag(
                                processing_node=processing_node)
        first_run = False

      try:
        #Sort activity list by priority
        activity_list = activity_dict.values()
        # Sort method must be local to access "self"
        def cmpActivities(activity_1, activity_2):
          return cmp(activity_1.getPriority(self), activity_2.getPriority(self))
        activity_list.sort(cmpActivities)
        
        # Wakeup each queue
        for activity in activity_list:
          activity.wakeup(inner_self, processing_node)

        # Process messages on each queue in round robin
        has_awake_activity = 1
        while has_awake_activity:
          has_awake_activity = 0
          for activity in activity_list:
            activity.tic(inner_self, processing_node) # Transaction processing is the responsability of the activity
            has_awake_activity = has_awake_activity or activity.isAwake(inner_self, processing_node)
      finally:
        # decrease the number of active_threads
        tic_lock.acquire()
        active_threads -= 1
        tic_lock.release()

    def hasActivity(self, *args, **kw):
      # Check in each queue if the object has deferred tasks
      # if not argument is provided, then check on self
      if len(args) > 0:
        obj = args[0]
      else:
        obj = self
      for activity in activity_dict.itervalues():
        if activity.hasActivity(aq_inner(self), obj, **kw):
          return True
      return False

    def getActivityBuffer(self, create_if_not_found=True):
      """
        Get activtity buffer for this thread for this activity tool.
        If no activity buffer is found at lowest level and create_if_not_found
        is True, create one.
        Intermediate level is unconditionaly created if non existant because
        chances are it will be used in the instance life.
        Lock is held when checking for intermediate level existance
        because:
         - intermediate level dict must not be created in 2 threads at the
           same time, since one creation would destroy the existing one.
        It's released after that step because:
         - lower level access is at thread scope, thus by definition there
           can be only one access at a time to a key
         - GIL protects us when accessing python instances
      """
      # Safeguard: make sure we are wrapped in  acquisition context before
      # using our path as an activity tool instance-wide identifier.
      assert getattr(self, 'aq_self', None) is not None
      my_instance_key = self.getPhysicalPath()
      my_thread_key = get_ident()
      global_activity_buffer_lock.acquire()
      try:
        if my_instance_key not in global_activity_buffer:
          global_activity_buffer[my_instance_key] = {}
      finally:
        global_activity_buffer_lock.release()
      thread_activity_buffer = global_activity_buffer[my_instance_key]
      if my_thread_key not in thread_activity_buffer:
        if create_if_not_found:
          buffer = ActivityBuffer(activity_tool=self)
        else:
          buffer = None
        thread_activity_buffer[my_thread_key] = buffer
      activity_buffer = thread_activity_buffer[my_thread_key]
      return activity_buffer

    security.declarePrivate('activateObject')
    def activateObject(self, object, activity, active_process, **kw):
      if not is_initialized:
        self.initialize()
      self.getActivityBuffer()
      return ActiveWrapper(object, activity, active_process, **kw)

    def deferredQueueMessage(self, activity, message):
      activity_buffer = self.getActivityBuffer()
      activity_buffer.deferredQueueMessage(self, activity, message)

    def deferredDeleteMessage(self, activity, message):
      activity_buffer = self.getActivityBuffer()
      activity_buffer.deferredDeleteMessage(self, activity, message)

    def getRegisteredMessageList(self, activity):
      activity_buffer = self.getActivityBuffer(create_if_not_found=False)
      if activity_buffer is not None:
        #activity_buffer._register() # This is required if flush flush is called outside activate
        return activity.getRegisteredMessageList(activity_buffer,
                                                 aq_inner(self))
      else:
        return []

    def unregisterMessage(self, activity, message):
      activity_buffer = self.getActivityBuffer()
      #activity_buffer._register()
      return activity.unregisterMessage(activity_buffer, aq_inner(self), message)

    def flush(self, obj, invoke=0, **kw):
      if not is_initialized:
        self.initialize()
      self.getActivityBuffer()
      if isinstance(obj, tuple):
        object_path = obj
      else:
        object_path = obj.getPhysicalPath()
      for activity in activity_dict.itervalues():
        activity.flush(aq_inner(self), object_path, invoke=invoke, **kw)

    def start(self, **kw):
      if not is_initialized:
        self.initialize()
      for activity in activity_dict.itervalues():
        activity.start(aq_inner(self), **kw)

    def stop(self, **kw):
      if not is_initialized:
        self.initialize()
      for activity in activity_dict.itervalues():
        activity.stop(aq_inner(self), **kw)

    def invoke(self, message):
      if logging:
        LOG('Activity Tracking', INFO, 'invoking message: object_path=%s, method_id=%s, args=%s, kw=%s, activity_kw=%s, user_name=%s' % ('/'.join(message.object_path), message.method_id, message.args, message.kw, message.activity_kw, message.user_name))
      if getattr(self, 'aq_chain', None) is not None:
        # Grab existing acquisition chain and extrach base objects.
        base_chain = [aq_base(x) for x in self.aq_chain]
        # Grab existig request (last chain item) and create a copy.
        request_container = base_chain.pop()
        request = request_container.REQUEST
        # XXX: REQUEST.clone() requires PARENTS to be set, and it's not when
        # runing unit tests. Recreate it if it does not exist.
        parents = getattr(request, 'PARENTS', None)
        if parents is None:
          warn('CMFActivity.ActivityTool.invoke: PARENTS is not defined in REQUEST. It should only happen in unit tests.')
          request['PARENTS'] = self.aq_chain[:]
        
        # restore request information
        new_request = request.clone()
        request_info = getattr(message, 'request_info', None)
        if request_info is not None:
          new_request.other['SERVER_URL'] = request_info['SERVER_URL']
          virtual_root_path = request_info.get('VirtualRootPhysicalPath')
          if virtual_root_path:
            new_request.other['VirtualRootPhysicalPath'] = virtual_root_path
          new_request.environ['HTTP_ACCEPT_LANGUAGE'] = request_info['HTTP_ACCEPT_LANGUAGE']
          new_request._script = request_info['_script']
        # Replace iHotfix Context, saving existing one
        ihotfix_context = iHotfix.Context(new_request)
        id = get_ident()
        iHotfix._the_lock.acquire()
        try:
          old_ihotfix_context = iHotfix.contexts.get(id)
          iHotfix.contexts[id] = ihotfix_context
        finally:
          iHotfix._the_lock.release()
        # Execute iHotfix "patch 2"
        new_request.processInputs()

        new_request_container = request_container.__class__(REQUEST=new_request)
        # Recreate acquisition chain.
        my_self = new_request_container
        base_chain.reverse()
        for item in base_chain:
          my_self = item.__of__(my_self)
      else:
        old_ihotfix_context = False
        my_self = self
        LOG('CMFActivity.ActivityTool.invoke', INFO, 'Strange: invoke is called outside of acquisition context.')
      try:
        message(my_self)
      finally:
        if old_ihotfix_context is not False:
          # Restore iHotfix context
          id = get_ident()
          iHotfix._the_lock.acquire()
          try:
            if old_ihotfix_context is None:
              del iHotfix.contexts[id]
            else:
              iHotfix.contexts[id] = old_ihotfix_context
          finally:
            iHotfix._the_lock.release()
      if logging:
        LOG('Activity Tracking', INFO, 'invoked message')
      if my_self is not self: # We rewrapped self
        for held in my_self.REQUEST._held:
          self.REQUEST._hold(held)

    def invokeGroup(self, method_id, message_list):
      if logging:
        LOG('Activity Tracking', INFO, 'invoking group messages: method_id=%s, paths=%s' % (method_id, ['/'.join(m.object_path) for m in message_list]))
      # Invoke a group method.
      object_list = []
      expanded_object_list = []
      new_message_list = []
      path_dict = {}
      # Filter the list of messages. If an object is not available, mark its message as non-executable.
      # In addition, expand an object if necessary, and make sure that no duplication happens.
      for m in message_list:
        # alternate method is used to segregate objects which cannot be grouped.
        alternate_method_id = m.activity_kw.get('alternate_method_id')
        try:
          obj = m.getObject(self)
        except KeyError:
          m.is_executed = MESSAGE_NOT_EXECUTABLE
          continue
        try:
          i = len(new_message_list) # This is an index of this message in new_message_list.
          if m.hasExpandMethod():
            for subobj in m.getObjectList(self):
              path = subobj.getPath()
              if path not in path_dict:
                path_dict[path] = i
                if alternate_method_id is not None \
                   and hasattr(aq_base(subobj), alternate_method_id):
                  # if this object is alternated, generate a new single active object.
                  activity_kw = m.activity_kw.copy()
                  if 'group_method_id' in activity_kw:
                    del activity_kw['group_method_id']
                  if 'group_id' in activity_kw:
                    del activity_kw['group_id']                    
                  active_obj = subobj.activate(**activity_kw)
                  getattr(active_obj, alternate_method_id)(*m.args, **m.kw)
                else:
                  expanded_object_list.append(subobj)
          else:
            path = obj.getPath()
            if path not in path_dict:
              path_dict[path] = i
              if alternate_method_id is not None \
                  and hasattr(aq_base(obj), alternate_method_id):
                # if this object is alternated, generate a new single active object.
                activity_kw = m.activity_kw.copy()
                if 'group_method_id' in activity_kw:
                  del activity_kw['group_method_id']
                if 'group_id' in activity_kw:
                  del activity_kw['group_id']
                active_obj = obj.activate(**activity_kw)
                getattr(active_obj, alternate_method_id)(*m.args, **m.kw)
              else:
                expanded_object_list.append(obj)
          object_list.append(obj)
          new_message_list.append(m)
        except:
          m.is_executed = MESSAGE_NOT_EXECUTED
          exc_info = sys.exc_info()
          m.exc_type = exc_info[0]
          m.exc_value = str(exc_info[1])
          m.traceback = ''.join(ExceptionFormatter.format_exception(
                                *exc_info))
          LOG('WARNING ActivityTool', 0,
              'Could not call method %s on object %s' %
              (m.method_id, m.object_path), error=exc_info)

      try:
        if len(expanded_object_list) > 0:
          method = self.unrestrictedTraverse(method_id)
          # FIXME: how to apply security here?
          # NOTE: expanded_object_list must be set to failed objects by the callee.
          #       If it fully succeeds, expanded_object_list must be empty when returning.
          result = method(expanded_object_list, **m.kw)
        else:
          result = None
      except:
        # In this case, the group method completely failed.
        exc_info = sys.exc_info()
        exc_type = exc_info[0]
        exc_value = str(exc_info[1])
        traceback = ''.join(ExceptionFormatter.format_exception(
                            *exc_info))
        for m in new_message_list:
          m.is_executed = MESSAGE_NOT_EXECUTED
          m.exc_type = exc_type
          m.exc_value = exc_value
          m.traceback = traceback
        LOG('WARNING ActivityTool', 0,
            'Could not call method %s on objects %s' %
            (method_id, expanded_object_list), error=exc_info)
      else:
        # Obtain all indices of failed messages. Note that this can be a partial failure.
        failed_message_dict = {}
        for obj in expanded_object_list:
          path = obj.getPath()
          i = path_dict[path]
          failed_message_dict[i] = None

        # Only for succeeded messages, an activity process is invoked (if any).
        for i in xrange(len(object_list)):
          object = object_list[i]
          m = new_message_list[i]
          if i in failed_message_dict:
            m.is_executed = MESSAGE_NOT_EXECUTED
            LOG('ActivityTool', WARNING,
                'the method %s partially failed on object %s' %
                (m.method_id, m.object_path,))
          else:
            try:
              m.activateResult(self, result, object)
              m.is_executed = MESSAGE_EXECUTED
            except:
              m.is_executed = MESSAGE_NOT_EXECUTED
              m.exc_type = sys.exc_info()[0]
              LOG('ActivityTool', WARNING,
                  'Could not call method %s on object %s' % (
                  m.method_id, m.object_path), error=sys.exc_info())
      if logging:
        LOG('Activity Tracking', INFO, 'invoked group messages')

    def newMessage(self, activity, path, active_process,
                   activity_kw, method_id, *args, **kw):
      # Some Security Cheking should be made here XXX
      if not is_initialized:
        self.initialize()
      self.getActivityBuffer()
      activity_dict[activity].queueMessage(aq_inner(self),
        Message(path, active_process, activity_kw, method_id, args, kw))

    security.declareProtected( CMFCorePermissions.ManagePortal, 'manageInvoke' )
    def manageInvoke(self, object_path, method_id, REQUEST=None):
      """
        Invokes all methods for object "object_path"
      """
      if type(object_path) is type(''):
        object_path = tuple(object_path.split('/'))
      self.flush(object_path,method_id=method_id,invoke=1)
      if REQUEST is not None:
        return REQUEST.RESPONSE.redirect('%s/%s' %
                (self.absolute_url(), 'manageActivities'))

    security.declareProtected( CMFCorePermissions.ManagePortal, 'manageCancel' )
    def manageCancel(self, object_path, method_id, REQUEST=None):
      """
        Cancel all methods for object "object_path"
      """
      if type(object_path) is type(''):
        object_path = tuple(object_path.split('/'))
      self.flush(object_path,method_id=method_id,invoke=0)
      if REQUEST is not None:
        return REQUEST.RESPONSE.redirect('%s/%s' %
                (self.absolute_url(), 'manageActivities'))

    security.declareProtected( CMFCorePermissions.ManagePortal,
                               'manageClearActivities' )
    def manageClearActivities(self, keep=1, REQUEST=None):
      """
        Clear all activities and recreate tables.
      """
      folder = getToolByName(self, 'portal_skins').activity

      # Obtain all pending messages.
      message_list = []
      if keep:
        for activity in activity_dict.itervalues():
          if hasattr(activity, 'dumpMessageList'):
            try:
              message_list.extend(activity.dumpMessageList(self))
            except ConflictError:
              raise
            except:
              LOG('ActivityTool', WARNING,
                  'could not dump messages from %s' %
                  (activity,), error=sys.exc_info())

      if getattr(folder, 'SQLDict_createMessageTable', None) is not None:
        try:
          folder.SQLDict_dropMessageTable()
        except ConflictError:
          raise
        except:
          LOG('CMFActivity', WARNING,
              'could not drop the message table',
              error=sys.exc_info())
        folder.SQLDict_createMessageTable()

      if getattr(folder, 'SQLQueue_createMessageTable', None) is not None:
        try:
          folder.SQLQueue_dropMessageTable()
        except ConflictError:
          raise
        except:
          LOG('CMFActivity', WARNING,
              'could not drop the message queue table',
              error=sys.exc_info())
        folder.SQLQueue_createMessageTable()

      # Reactivate the messages.
      for m in message_list:
        try:
          m.reactivate(aq_inner(self))
        except ConflictError:
          raise
        except:
          LOG('ActivityTool', WARNING,
              'could not reactivate the message %r, %r' %
              (m.object_path, m.method_id), error=sys.exc_info())

      if REQUEST is not None:
        message = 'Activities%20Cleared'
        if keep:
          message = 'Tables%20Recreated'
        return REQUEST.RESPONSE.redirect(
            '%s/manageActivitiesAdvanced?manage_tabs_message=%s' % (
              self.absolute_url(), message))

    security.declarePublic('getMessageList')
    def getMessageList(self,**kw):
      """
        List messages waiting in queues
      """
      # Initialize if needed
      if not is_initialized:
        self.initialize()

      message_list = []
      for activity in activity_dict.itervalues():
        try:
          message_list += activity.getMessageList(aq_inner(self),**kw)
        except AttributeError:
          LOG('getMessageList, could not get message from Activity:',0,activity)
      return message_list

    security.declarePublic('countMessageWithTag')
    def countMessageWithTag(self, value):
      """
        Return the number of messages which match the given tag.
      """
      message_count = 0
      for activity in activity_dict.itervalues():
        message_count += activity.countMessageWithTag(aq_inner(self), value)
      return message_count

    security.declarePublic('countMessage')
    def countMessage(self, **kw):
      """
        Return the number of messages which match the given parameter.

        Parameters allowed:

        method_id : the id of the method
        path : for activities on a particular object
        tag : activities with a particular tag
        message_uid : activities with a particular uid
      """
      message_count = 0
      for activity in activity_dict.itervalues():
        message_count += activity.countMessage(aq_inner(self), **kw)
      return message_count

    security.declareProtected( CMFCorePermissions.ManagePortal , 'newActiveProcess' )
    def newActiveProcess(self, **kw):
      from ActiveProcess import addActiveProcess
      new_id = str(self.generateNewId())
      addActiveProcess(self, new_id)
      active_process = self._getOb(new_id)
      active_process.edit(**kw)
      return active_process

    def reindexObject(self):
      self.immediateReindexObject()

    # Active synchronisation methods
    security.declarePrivate('validateOrder')
    def validateOrder(self, message, validator_id, validation_value):
      message_list = self.getDependentMessageList(message, validator_id, validation_value)
      return len(message_list) > 0

    security.declarePrivate('getDependentMessageList')
    def getDependentMessageList(self, message, validator_id, validation_value):
      if not is_initialized:
        self.initialize()
      message_list = []
      method_id = "_validate_%s" % validator_id
      for activity in activity_dict.itervalues():
        method = getattr(activity, method_id, None)
        if method is not None:
          result = method(aq_inner(self), message, validation_value)
          if result:
            message_list.extend([(activity, m) for m in result])
      return message_list

    # Required for tests (time shift)
    def timeShift(self, delay):
      if not is_initialized:
        self.initialize()
      for activity in activity_dict.itervalues():
        activity.timeShift(aq_inner(self), delay)

InitializeClass(ActivityTool)