def __init__(self, obj, func, *args, **kwargs):
        if not self._registered_with_atexit:
            # We may register the exit function more than once because
            # of a thread race, but that is harmless
            import atexit
            atexit.register(self._exitfunc)
            finalize._registered_with_atexit = True
        info = self._Info()
        info.weakref = ref(obj, self)
        info.func = func
        info.args = args
        info.kwargs = kwargs or None
        info.atexit = True
        info.index = next(self._index_iter)
        self._registry[self] = info
        finalize._dirty = True 

def create_dict(self):
        """Create a new dict for the current thread, and return it."""
        localdict = {}
        key = self.key
        thread = current_thread()
        idt = id(thread)
        def local_deleted(_, key=key):
            # When the localimpl is deleted, remove the thread attribute.
            thread = wrthread()
            if thread is not None:
                del thread.__dict__[key]
        def thread_deleted(_, idt=idt):
            # When the thread is deleted, remove the local dict.
            # Note that this is suboptimal if the thread object gets
            # caught in a reference loop. We would like to be called
            # as soon as the OS-level thread ends instead.
            local = wrlocal()
            if local is not None:
                dct = local.dicts.pop(idt)
        wrlocal = ref(self, local_deleted)
        wrthread = ref(thread, thread_deleted)
        thread.__dict__[key] = wrlocal
        self.dicts[idt] = wrthread, localdict
        return localdict 

def subscribe(func):
    '''
    Add a subscriber function to option events

    Parameters
    ----------
    func : callable
        A callable object that takes two parameters: key and value.
        This function is called with the name and value of any option
        that is set.

    Returns
    -------
    None

    '''
    if isinstance(func, types.MethodType):
        obj = six.get_method_self(func)
        func = six.get_method_function(func)
        _subscribers[func] = (weakref.ref(func), weakref.ref(obj))
    else:
        _subscribers[func] = (weakref.ref(func), None) 

def ensure_proc_terminate(proc):
    """
    Make sure processes terminate when main process exit.

    Args:
        proc (multiprocessing.Process or list)
    """
    if isinstance(proc, list):
        for p in proc:
            ensure_proc_terminate(p)
        return

    def stop_proc_by_weak_ref(ref):
        proc = ref()
        if proc is None:
            return
        if not proc.is_alive():
            return
        proc.terminate()
        proc.join()

    assert isinstance(proc, mp.Process)
    atexit.register(stop_proc_by_weak_ref, weakref.ref(proc)) 

def lex(self, source, name=None, filename=None):
        """Lex the given sourcecode and return a generator that yields
        tokens as tuples in the form ``(lineno, token_type, value)``.
        This can be useful for :ref:`extension development <writing-extensions>`
        and debugging templates.

        This does not perform preprocessing.  If you want the preprocessing
        of the extensions to be applied you have to filter source through
        the :meth:`preprocess` method.
        """
        source = text_type(source)
        try:
            return self.lexer.tokeniter(source, name, filename)
        except TemplateSyntaxError:
            exc_info = sys.exc_info()
        self.handle_exception(exc_info, source_hint=source) 

def lex(self, source, name=None, filename=None):
        """Lex the given sourcecode and return a generator that yields
        tokens as tuples in the form ``(lineno, token_type, value)``.
        This can be useful for :ref:`extension development <writing-extensions>`
        and debugging templates.

        This does not perform preprocessing.  If you want the preprocessing
        of the extensions to be applied you have to filter source through
        the :meth:`preprocess` method.
        """
        source = text_type(source)
        try:
            return self.lexer.tokeniter(source, name, filename)
        except TemplateSyntaxError:
            exc_info = sys.exc_info()
        self.handle_exception(exc_info, source_hint=source) 

def _adjust_thread_count(self):
        # if idle threads are available, don't spin new threads
        if self._idle_semaphore.acquire(False):
            return

        # When the executor gets lost, the weakref callback will wake up
        # the worker threads.
        def weakref_cb(_, q=self._work_queue):
            q.put(None)

        num_threads = len(self._threads)
        if num_threads < self._max_workers:
            thread_name = '%s_%d' % (self._thread_name_prefix or self,
                                     num_threads)
            t = threading.Thread(name=thread_name, target=_worker,
                                 args=(weakref.ref(self, weakref_cb),
                                       self._work_queue))
            t.daemon = True
            t.start()
            self._threads.add(t)
            _threads_queues[t] = self._work_queue 

def _start_queue_management_thread(self):
        # When the executor gets lost, the weakref callback will wake up
        # the queue management thread.
        def weakref_cb(_, q=self._result_queue):
            q.put(None)
        if self._queue_management_thread is None:
            self._queue_management_thread = threading.Thread(
                    target=_queue_management_worker,
                    args=(weakref.ref(self, weakref_cb),
                          self._processes,
                          self._pending_work_items,
                          self._work_ids,
                          self._call_queue,
                          self._result_queue))
            self._queue_management_thread.daemon = True
            self._queue_management_thread.start()
            _threads_queues[self._queue_management_thread] = self._result_queue 

def test_task_refcounting(self):
        # On CPython, tasks and their arguments should be released immediately
        # without waiting for garbage collection.
        @gen.engine
        def f():
            class Foo(object):
                pass
            arg = Foo()
            self.arg_ref = weakref.ref(arg)
            task = gen.Task(self.io_loop.add_callback, arg=arg)
            self.task_ref = weakref.ref(task)
            yield task
            self.stop()

        self.run_gen(f)
        self.assertIs(self.arg_ref(), None)
        self.assertIs(self.task_ref(), None) 

def test_task_refcounting(self):
        # On CPython, tasks and their arguments should be released immediately
        # without waiting for garbage collection.
        @gen.engine
        def f():
            class Foo(object):
                pass
            arg = Foo()
            self.arg_ref = weakref.ref(arg)
            task = gen.Task(self.io_loop.add_callback, arg=arg)
            self.task_ref = weakref.ref(task)
            yield task
            self.stop()

        self.run_gen(f)
        self.assertIs(self.arg_ref(), None)
        self.assertIs(self.task_ref(), None) 

def _start_queue_management_thread(self):
        # When the executor gets lost, the weakref callback will wake up
        # the queue management thread.
        def weakref_cb(_, q=self._result_queue):
            q.put(None)
        if self._queue_management_thread is None:
            self._queue_management_thread = threading.Thread(
                    target=_queue_management_worker,
                    args=(weakref.ref(self, weakref_cb),
                          self._processes,
                          self._pending_work_items,
                          self._work_ids,
                          self._call_queue,
                          self._result_queue))
            self._queue_management_thread.daemon = True
            self._queue_management_thread.start()
            _threads_queues[self._queue_management_thread] = self._result_queue 

def _adjust_thread_count(self):
        # When the executor gets lost, the weakref callback will wake up
        # the worker threads.
        def weakref_cb(_, q=self._work_queue):
            q.put(None)
        # TODO(bquinlan): Should avoid creating new threads if there are more
        # idle threads than items in the work queue.
        num_threads = len(self._threads)
        if num_threads < self._max_workers:
            thread_name = '%s_%d' % (self._thread_name_prefix or self,
                                     num_threads)
            t = threading.Thread(name=thread_name, target=_worker,
                                 args=(weakref.ref(self, weakref_cb),
                                       self._work_queue))
            t.daemon = True
            t.start()
            self._threads.add(t)
            _threads_queues[t] = self._work_queue 

def _start_queue_management_thread(self):
        # When the executor gets lost, the weakref callback will wake up
        # the queue management thread.
        def weakref_cb(_, q=self._result_queue):
            q.put(None)
        if self._queue_management_thread is None:
            self._queue_management_thread = threading.Thread(
                    target=_queue_management_worker,
                    args=(weakref.ref(self, weakref_cb),
                          self._processes,
                          self._pending_work_items,
                          self._work_ids,
                          self._call_queue,
                          self._result_queue))
            self._queue_management_thread.daemon = True
            self._queue_management_thread.start()
            _threads_queues[self._queue_management_thread] = self._result_queue 

def lex(self, source, name=None, filename=None):
        """Lex the given sourcecode and return a generator that yields
        tokens as tuples in the form ``(lineno, token_type, value)``.
        This can be useful for :ref:`extension development <writing-extensions>`
        and debugging templates.

        This does not perform preprocessing.  If you want the preprocessing
        of the extensions to be applied you have to filter source through
        the :meth:`preprocess` method.
        """
        source = text_type(source)
        try:
            return self.lexer.tokeniter(source, name, filename)
        except TemplateSyntaxError:
            exc_info = sys.exc_info()
        self.handle_exception(exc_info, source_hint=source) 

def attach(self, hooks_dict, hook):
        assert not self._hooks_dict_ref, 'The same handle cannot be attached twice.'
        self._id = id(hook)
        hooks_dict[self._id] = hook
        self._hooks_dict_ref = weakref.ref(hooks_dict) 

def __setstate__(self, state):
        if state[0] is None:
            self._hooks_dict_ref = weakref.ref(collections.OrderedDict())
        else:
            self._hooks_dict_ref = weakref.ref(state[0])
        self._id = state[1] 

def _create_accelerator(self, builder, traverser):
        obj = self._native.create_accelerator(builder, traverser)
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_geometry(self):
        obj = self._native.create_geometry()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_buffer(self, buffer_type):
        obj = self._native.create_buffer(buffer_type)
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_geometry_group(self):
        obj = self._native.create_geometry_group()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_geometry_instance(self):
        obj = self._native.create_geometry_instance()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_material(self):
        obj = self._native.create_material()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_program_from_file(self, file_name, function_name):
        obj = self._native.create_program_from_file(file_name, function_name)
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_selector(self):
        obj = self._native.create_selector()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_texture_sampler(self):
        obj = self._native.create_texture_sampler()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def _create_transform(self):
        obj = self._native.create_transform()
        self._destroyables.append(weakref.ref(obj))
        return obj 

def obj_node_id(obj):
    if isinstance(obj, weakref.ref):
        return 'all_weakrefs_are_one'
    return ('o%d' % id(obj)).replace('-', '_') 

def short_repr(obj):
    if isinstance(obj, (type, types.ModuleType, types.BuiltinMethodType,
                        types.BuiltinFunctionType)):
        return obj.__name__
    if isinstance(obj, types.MethodType):
        if obj.im_self is not None:
            return obj.im_func.__name__ + ' (bound)'
        else:
            return obj.im_func.__name__
    if isinstance(obj, (tuple, list, dict, set)):
        return '%d items' % len(obj)
    if isinstance(obj, weakref.ref):
        return 'all_weakrefs_are_one'
    return repr(obj)[:40] 

def testNoCycles(self):
        case = unittest.TestCase()
        wr = weakref.ref(case)
        with support.disable_gc():
            del case
            self.assertFalse(wr()) 

def testRegisterResult(self):
        result = unittest.TestResult()
        unittest.registerResult(result)

        for ref in unittest.signals._results:
            if ref is result:
                break
            elif ref is not result:
                self.fail("odd object in result set")
        else:
            self.fail("result not found")