Merge pull request #2163 from apollo13/signals

include django/contrib/gis/gdal/LICENSE

include django/contrib/gis/geos/LICENSE

include django/dispatch/license.txt

include django/dispatch/license.python.txt

recursive-include docs *

recursive-include scripts *

recursive-include extras *

import weakref

import sys

import threading

import weakref

from django.dispatch import saferef

from django.utils.six.moves import xrange

WEAKREF_TYPES = (weakref.ReferenceType, saferef.BoundMethodWeakref)

if sys.version_info < (3,4):

    from .weakref_backports import WeakMethod

else:

    from weakref import WeakMethod

def _make_id(target):

                A function or an instance method which is to receive signals.

                Receivers must be hashable objects.

                If weak is True, then receiver must be weak-referencable (more

                precisely saferef.safeRef() must be able to create a reference

                to the receiver).

                If weak is True, then receiver must be weak-referencable.

                Receivers must be able to accept keyword arguments.

                assert argspec[2] is not None, \

                    "Signal receivers must accept keyword arguments (**kwargs)."

        receiver_id = _make_id(receiver)

        if dispatch_uid:

            lookup_key = (dispatch_uid, _make_id(sender))

        else:

            lookup_key = (_make_id(receiver), _make_id(sender))

            lookup_key = (receiver_id, _make_id(sender))

        if weak:

            receiver = saferef.safeRef(receiver, onDelete=self._remove_receiver)

            ref = weakref.ref

            original_receiver = receiver

            # Check for bound methods

            if hasattr(receiver, '__self__') and hasattr(receiver, '__func__'):

                ref = WeakMethod

                original_receiver = original_receiver.__self__

            if sys.version_info >= (3, 4):

                receiver = ref(receiver)

                weakref.finalize(original_receiver, self._remove_receiver, receiver_id=receiver_id)

            else:

                receiver = ref(receiver, self._remove_receiver)

                # Use the id of the weakref, since that's what passed to the weakref callback!

                receiver_id = _make_id(receiver)

        with self.lock:

            for r_key, _ in self.receivers:

            for r_key, _, _ in self.receivers:

                if r_key == lookup_key:

                    break

            else:

                self.receivers.append((lookup_key, receiver))

                self.receivers.append((lookup_key, receiver, receiver_id))

            self.sender_receivers_cache.clear()

    def disconnect(self, receiver=None, sender=None, weak=True, dispatch_uid=None):

        with self.lock:

            for index in xrange(len(self.receivers)):

                (r_key, _) = self.receivers[index]

                (r_key, _, _) = self.receivers[index]

                if r_key == lookup_key:

                    del self.receivers[index]

                    break

            with self.lock:

                senderkey = _make_id(sender)

                receivers = []

                for (receiverkey, r_senderkey), receiver in self.receivers:

                for (receiverkey, r_senderkey), receiver, _ in self.receivers:

                    if r_senderkey == NONE_ID or r_senderkey == senderkey:

                        receivers.append(receiver)

                if self.use_caching:

                        self.sender_receivers_cache[sender] = receivers

        non_weak_receivers = []

        for receiver in receivers:

            if isinstance(receiver, WEAKREF_TYPES):

            if isinstance(receiver, weakref.ReferenceType):

                # Dereference the weak reference.

                receiver = receiver()

                if receiver is not None:

                non_weak_receivers.append(receiver)

        return non_weak_receivers

    def _remove_receiver(self, receiver):

    def _remove_receiver(self, receiver=None, receiver_id=None, _make_id=_make_id):

        """

        Remove dead receivers from connections.

        """

        `receiver_id` is used by python 3.4 and up. `receiver` is used in older

        versions and is the weakref to the receiver (if the connection was defined

        as `weak`). We also need to pass on `_make_id` since the original reference

        will be None during module shutdown.

        """

        with self.lock:

            to_remove = []

            for key, connected_receiver in self.receivers:

                if connected_receiver == receiver:

                    to_remove.append(key)

            for key in to_remove:

                last_idx = len(self.receivers) - 1

                # enumerate in reverse order so that indexes are valid even

                # after we delete some items

                for idx, (r_key, _) in enumerate(reversed(self.receivers)):

                    if r_key == key:

                        del self.receivers[last_idx - idx]

            if receiver is not None:

                receiver_id = _make_id(receiver)

            self.receivers[:] = [val for val in self.receivers if val[2] != receiver_id]

            self.sender_receivers_cache.clear()

A. HISTORY OF THE SOFTWARE

==========================

Python was created in the early 1990s by Guido van Rossum at Stichting

Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands

as a successor of a language called ABC.  Guido remains Python's

principal author, although it includes many contributions from others.

In 1995, Guido continued his work on Python at the Corporation for

National Research Initiatives (CNRI, see http://www.cnri.reston.va.us)

in Reston, Virginia where he released several versions of the

software.

In May 2000, Guido and the Python core development team moved to

BeOpen.com to form the BeOpen PythonLabs team.  In October of the same

year, the PythonLabs team moved to Digital Creations (now Zope

Corporation, see http://www.zope.com).  In 2001, the Python Software

Foundation (PSF, see http://www.python.org/psf/) was formed, a

non-profit organization created specifically to own Python-related

Intellectual Property.  Zope Corporation is a sponsoring member of

the PSF.

All Python releases are Open Source (see http://www.opensource.org for

the Open Source Definition).  Historically, most, but not all, Python

releases have also been GPL-compatible; the table below summarizes

the various releases.

    Release         Derived     Year        Owner       GPL-

                    from                                compatible? (1)

    0.9.0 thru 1.2              1991-1995   CWI         yes

    1.3 thru 1.5.2  1.2         1995-1999   CNRI        yes

    1.6             1.5.2       2000        CNRI        no

    2.0             1.6         2000        BeOpen.com  no

    1.6.1           1.6         2001        CNRI        yes (2)

    2.1             2.0+1.6.1   2001        PSF         no

    2.0.1           2.0+1.6.1   2001        PSF         yes

    2.1.1           2.1+2.0.1   2001        PSF         yes

    2.1.2           2.1.1       2002        PSF         yes

    2.1.3           2.1.2       2002        PSF         yes

    2.2 and above   2.1.1       2001-now    PSF         yes

Footnotes:

(1) GPL-compatible doesn't mean that we're distributing Python under

    the GPL.  All Python licenses, unlike the GPL, let you distribute

    a modified version without making your changes open source.  The

    GPL-compatible licenses make it possible to combine Python with

    other software that is released under the GPL; the others don't.

(2) According to Richard Stallman, 1.6.1 is not GPL-compatible,

    because its license has a choice of law clause.  According to

    CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1

    is "not incompatible" with the GPL.

Thanks to the many outside volunteers who have worked under Guido's

direction to make these releases possible.

B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON

===============================================================

PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2

--------------------------------------------

1. This LICENSE AGREEMENT is between the Python Software Foundation

("PSF"), and the Individual or Organization ("Licensee") accessing and

otherwise using this software ("Python") in source or binary form and

its associated documentation.

2. Subject to the terms and conditions of this License Agreement, PSF hereby

grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,

analyze, test, perform and/or display publicly, prepare derivative works,

distribute, and otherwise use Python alone or in any derivative version,

provided, however, that PSF's License Agreement and PSF's notice of copyright,

i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,

2011, 2012, 2013, 2014 Python Software Foundation; All Rights Reserved" are retained

in Python alone or in any derivative version prepared by Licensee.

3. In the event Licensee prepares a derivative work that is based on

or incorporates Python or any part thereof, and wants to make

the derivative work available to others as provided herein, then

Licensee hereby agrees to include in any such work a brief summary of

the changes made to Python.

4. PSF is making Python available to Licensee on an "AS IS"

basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR

IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND

DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS

FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT

INFRINGE ANY THIRD PARTY RIGHTS.

5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON

FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS

A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,

OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

6. This License Agreement will automatically terminate upon a material

breach of its terms and conditions.

7. Nothing in this License Agreement shall be deemed to create any

relationship of agency, partnership, or joint venture between PSF and

Licensee.  This License Agreement does not grant permission to use PSF

trademarks or trade name in a trademark sense to endorse or promote

products or services of Licensee, or any third party.

8. By copying, installing or otherwise using Python, Licensee

agrees to be bound by the terms and conditions of this License

Agreement.

BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0

-------------------------------------------

BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1

1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an

office at 160 Saratoga Avenue, Santa Clara, CA 95051, and the

Individual or Organization ("Licensee") accessing and otherwise using

this software in source or binary form and its associated

documentation ("the Software").

2. Subject to the terms and conditions of this BeOpen Python License

Agreement, BeOpen hereby grants Licensee a non-exclusive,

royalty-free, world-wide license to reproduce, analyze, test, perform

and/or display publicly, prepare derivative works, distribute, and

otherwise use the Software alone or in any derivative version,

provided, however, that the BeOpen Python License is retained in the

Software, alone or in any derivative version prepared by Licensee.

3. BeOpen is making the Software available to Licensee on an "AS IS"

basis.  BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR

IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND

DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS

FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF THE SOFTWARE WILL NOT

INFRINGE ANY THIRD PARTY RIGHTS.

4. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE

SOFTWARE FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS

AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY

DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

5. This License Agreement will automatically terminate upon a material

breach of its terms and conditions.

6. This License Agreement shall be governed by and interpreted in all

respects by the law of the State of California, excluding conflict of

law provisions.  Nothing in this License Agreement shall be deemed to

create any relationship of agency, partnership, or joint venture

between BeOpen and Licensee.  This License Agreement does not grant

permission to use BeOpen trademarks or trade names in a trademark

sense to endorse or promote products or services of Licensee, or any

third party.  As an exception, the "BeOpen Python" logos available at

http://www.pythonlabs.com/logos.html may be used according to the

permissions granted on that web page.

7. By copying, installing or otherwise using the software, Licensee

agrees to be bound by the terms and conditions of this License

Agreement.

CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1

---------------------------------------

1. This LICENSE AGREEMENT is between the Corporation for National

Research Initiatives, having an office at 1895 Preston White Drive,

Reston, VA 20191 ("CNRI"), and the Individual or Organization

("Licensee") accessing and otherwise using Python 1.6.1 software in

source or binary form and its associated documentation.

2. Subject to the terms and conditions of this License Agreement, CNRI

hereby grants Licensee a nonexclusive, royalty-free, world-wide

license to reproduce, analyze, test, perform and/or display publicly,

prepare derivative works, distribute, and otherwise use Python 1.6.1

alone or in any derivative version, provided, however, that CNRI's

License Agreement and CNRI's notice of copyright, i.e., "Copyright (c)

1995-2001 Corporation for National Research Initiatives; All Rights

Reserved" are retained in Python 1.6.1 alone or in any derivative

version prepared by Licensee.  Alternately, in lieu of CNRI's License

Agreement, Licensee may substitute the following text (omitting the

quotes): "Python 1.6.1 is made available subject to the terms and

conditions in CNRI's License Agreement.  This Agreement together with

Python 1.6.1 may be located on the Internet using the following

unique, persistent identifier (known as a handle): 1895.22/1013.  This

Agreement may also be obtained from a proxy server on the Internet

using the following URL: http://hdl.handle.net/1895.22/1013".

3. In the event Licensee prepares a derivative work that is based on

or incorporates Python 1.6.1 or any part thereof, and wants to make

the derivative work available to others as provided herein, then

Licensee hereby agrees to include in any such work a brief summary of

the changes made to Python 1.6.1.

4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS"

basis.  CNRI MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR

IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, CNRI MAKES NO AND

DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS

FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON 1.6.1 WILL NOT

INFRINGE ANY THIRD PARTY RIGHTS.

5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON

1.6.1 FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS

A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1,

OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

6. This License Agreement will automatically terminate upon a material

breach of its terms and conditions.

7. This License Agreement shall be governed by the federal

intellectual property law of the United States, including without

limitation the federal copyright law, and, to the extent such

U.S. federal law does not apply, by the law of the Commonwealth of

Virginia, excluding Virginia's conflict of law provisions.

Notwithstanding the foregoing, with regard to derivative works based

on Python 1.6.1 that incorporate non-separable material that was

previously distributed under the GNU General Public License (GPL), the

law of the Commonwealth of Virginia shall govern this License

Agreement only as to issues arising under or with respect to

Paragraphs 4, 5, and 7 of this License Agreement.  Nothing in this

License Agreement shall be deemed to create any relationship of

agency, partnership, or joint venture between CNRI and Licensee.  This

License Agreement does not grant permission to use CNRI trademarks or

trade name in a trademark sense to endorse or promote products or

services of Licensee, or any third party.

8. By clicking on the "ACCEPT" button where indicated, or by copying,

installing or otherwise using Python 1.6.1, Licensee agrees to be

bound by the terms and conditions of this License Agreement.

        ACCEPT

CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2

--------------------------------------------------

Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam,

The Netherlands.  All rights reserved.

Permission to use, copy, modify, and distribute this software and its

documentation for any purpose and without fee is hereby granted,

provided that the above copyright notice appear in all copies and that

both that copyright notice and this permission notice appear in

supporting documentation, and that the name of Stichting Mathematisch

Centrum or CWI not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior

permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO

THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE

FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT

OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""

weakref_backports is a partial backport of the weakref module for python

versions below 3.4.

Copyright (C) 2013 Python Software Foundation, see license.python.txt for

details.

The following changes were made to the original sources during backporting:

 * Added `self` to `super` calls.

 * Removed `from None` when raising exceptions.

"""

from weakref import ref

class WeakMethod(ref):

    """

    A custom `weakref.ref` subclass which simulates a weak reference to

    a bound method, working around the lifetime problem of bound methods.

    """

    __slots__ = "_func_ref", "_meth_type", "_alive", "__weakref__"

    def __new__(cls, meth, callback=None):

        try:

            obj = meth.__self__

            func = meth.__func__

        except AttributeError:

            raise TypeError("argument should be a bound method, not {}"

                            .format(type(meth)))

        def _cb(arg):

            # The self-weakref trick is needed to avoid creating a reference

            # cycle.

            self = self_wr()

            if self._alive:

                self._alive = False

                if callback is not None:

                    callback(self)

        self = ref.__new__(cls, obj, _cb)

        self._func_ref = ref(func, _cb)

        self._meth_type = type(meth)

        self._alive = True

        self_wr = ref(self)

        return self

    def __call__(self):

        obj = super(WeakMethod, self).__call__()

        func = self._func_ref()

        if obj is None or func is None:

            return None

        return self._meth_type(func, obj)

    def __eq__(self, other):

        if isinstance(other, WeakMethod):

            if not self._alive or not other._alive:

                return self is other

            return ref.__eq__(self, other) and self._func_ref == other._func_ref

        return False

    def __ne__(self, other):

        if isinstance(other, WeakMethod):

            if not self._alive or not other._alive:

                return self is not other

            return ref.__ne__(self, other) or self._func_ref != other._func_ref

        return True

    __hash__ = ref.__hash__