def inst(func):

	return func()





class IterDict(dict):

  keylist = []

  @staticmethod

  def keylistiter_():

    print IterDict.keylist

    index = 0

    while 1:

      if index >= len(IterDict.keylist): index = 0

      if not IterDict.keylist: break

      yield IterDict.keylist[index]

      index += 1

  keylistiter = keylistiter_.__get__(1)()

  @classmethod

  def reset(cls): cls.keylistiter = cls.keylistiter_()

  def __setitem__(self, name, value):

    if name not in self.keylist:

        self.keylist.append(name)

    dict.__setitem__(self, name, value)

  def __delitem__(self, name):

    if name in self.keylist:

      del self.keylist[self.keylist.index(name)]

	dict.__delitem__(self, name)





import itertools





class CONT(object): pass

    



class PIDmanager(object):

	queue = IterDict()

	tasks = None

	@inst

	def pid_generator():

		counter = 0

		while 1:

			yield counter

			counter += 1

	@classmethod

	def put_task(self, task):

		pid = self.pid_generator.next()

		self.queue[pid] = task

        print pid

		if self.tasks == None:

            self.queue.reset()

			self.tasks = self.queue.keylistiter

            self.tasks.next()

	@classmethod

	def run_task(self):

		if self.tasks != None:

			pid = self.tasks.next()

			task = self.queue[pid]

			if hasattr(task, '__iter__') and isinstance(task[0], CONT):

				_, func, args, kwargs, cleanup = task

                result = []

				self.queue[pid] = func(*args, **kwargs)

				cleanup()

                return self.queue[pid]

			else:

				del self.queue[pid]

                return task

    @classmethod

    def run_all(self):

        try:

            while 1: self.run_task()

        except StopIteration:

            self.queue.reset()

            self.tasks == None





def print_many(gen, total=2000, count=0):

	print gen.next(),

	if count < total:

		return CONT(), print_many, (gen,), dict(total=total, count=count+1), cleanup





def cleanup(): print





PIDmanager.put_task( (CONT(), print_many, (itertools.cycle('a'),), dict(total=10), cleanup) )

PIDmanager.put_task( (CONT(), print_many, (itertools.cycle('b'),), dict(total=10), cleanup) )

PIDmanager.run_task()