mirror of
https://github.com/RustPython/RustPython.git
synced 2026-10-28 18:59:04 +08:00
youknowdot
7d15b50cd4
* Align weak-reference collection with Python 3.15 finalization Trace and retain owned callback edges independently of weak referent links. Clear callback-bearing weakrefs before finalizers, suppress callbacks from unreachable weakrefs, and close remaining weakref ingress after resurrection checks while the world is stopped. Publish and unlink intrusive nodes safely. Refresh weakref and canonical weakref/GC/finalization tests through update_lib from pinned CPython 3.15.0. Retire four obsolete guards only after fresh body passes, retaining applicable RustPython limitations. Assisted-by: OpenAI Codex:model version unavailable * Refresh canonical IO tests for weakref finalization Migrate the complete CPython 3.15.0 test_io package at d220409 with the fail-closed legacy-map updater, preserving all ten existing guards. Retire the seven consolidated standalone suites and update io/file dependency paths with mapping regression tests. The canonical GC tests ignore ResourceWarning without retaining its source, so callback-free weakrefs correctly reflect surviving owners. This closes the stale test dependency exposed by the lifecycle change. Assisted-by: OpenAI Codex:model version unavailable * Protect weakref callbacks with the original referent stripe Follow CPython's free-threading weakref locking model instead of keeping an independent callback RwLock. Retain the original referent stripe key so callback access stays synchronized after GC clears the referent. Unlink and steal callbacks under that stripe, then release ownership outside the lock. Preserve synchronization for running-world GC paths and gc.get_referents while keeping ordinary weakref upgrades unchanged. Assisted-by: OpenAI Codex:model version unavailable * Defer weakref GC tracking until referent publication Keep freshly allocated weakrefs out of GC's object lists until they are linked and their referent is published. Release the referent stripe before tracking, since tracking can collect and invoke finalizers. Generic reuse losers remain untracked. Exercise the allocator boundary directly for reference, proxy, callable proxy and subclass payloads, and ensure completed constructors track their objects. This prevents observers from retaining a half-built dead weakref that later becomes live. Assisted-by: OpenAI Codex:model version unavailable * Retain the original weakref stripe lock like CPython Store a safe handle to the selected static weakref stripe instead of retaining and rehashing the referent address. Keep the same lock after referent clearing, matching CPython free-threaded weakrefs_lock. The nonthreaded handle is zero-sized and introduces no locking. Preserve lock selection, acquire/release ordering, fork reset, deferred GC publication, and callback-owner release outside the stripe. No new locks or unsafe code are needed. Assisted-by: OpenAI Codex:model version unavailable
577 lines
17 KiB
Python
Vendored
577 lines
17 KiB
Python
Vendored
"""Weak reference support for Python.
|
|
|
|
This module is an implementation of PEP 205:
|
|
|
|
https://peps.python.org/pep-0205/
|
|
"""
|
|
|
|
# Naming convention: Variables named "wr" are weak reference objects;
|
|
# they are called this instead of "ref" to avoid name collisions with
|
|
# the module-global ref() function imported from _weakref.
|
|
|
|
from _weakref import (
|
|
getweakrefcount,
|
|
getweakrefs,
|
|
ref,
|
|
proxy,
|
|
CallableProxyType,
|
|
ProxyType,
|
|
ReferenceType,
|
|
_remove_dead_weakref)
|
|
|
|
from _weakrefset import WeakSet
|
|
|
|
import _collections_abc # Import after _weakref to avoid circular import.
|
|
import sys
|
|
import itertools
|
|
|
|
ProxyTypes = (ProxyType, CallableProxyType)
|
|
|
|
__all__ = ["ref", "proxy", "getweakrefcount", "getweakrefs",
|
|
"WeakKeyDictionary", "ReferenceType", "ProxyType",
|
|
"CallableProxyType", "ProxyTypes", "WeakValueDictionary",
|
|
"WeakSet", "WeakMethod", "finalize"]
|
|
|
|
|
|
_collections_abc.MutableSet.register(WeakSet)
|
|
|
|
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))) from None
|
|
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().__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 NotImplemented
|
|
|
|
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 NotImplemented
|
|
|
|
__hash__ = ref.__hash__
|
|
|
|
|
|
class WeakValueDictionary(_collections_abc.MutableMapping):
|
|
"""Mapping class that references values weakly.
|
|
|
|
Entries in the dictionary will be discarded when no strong
|
|
reference to the value exists anymore
|
|
"""
|
|
# We inherit the constructor without worrying about the input
|
|
# dictionary; since it uses our .update() method, we get the right
|
|
# checks (if the other dictionary is a WeakValueDictionary,
|
|
# objects are unwrapped on the way out, and we always wrap on the
|
|
# way in).
|
|
|
|
def __init__(self, other=(), /, **kw):
|
|
def remove(wr, selfref=ref(self), _atomic_removal=_remove_dead_weakref):
|
|
self = selfref()
|
|
if self is not None:
|
|
# Atomic removal is necessary since this function
|
|
# can be called asynchronously by the GC
|
|
_atomic_removal(self.data, wr.key)
|
|
self._remove = remove
|
|
self.data = {}
|
|
self.update(other, **kw)
|
|
|
|
def __getitem__(self, key):
|
|
o = self.data[key]()
|
|
if o is None:
|
|
raise KeyError(key)
|
|
else:
|
|
return o
|
|
|
|
def __delitem__(self, key):
|
|
del self.data[key]
|
|
|
|
def __len__(self):
|
|
return len(self.data)
|
|
|
|
def __contains__(self, key):
|
|
try:
|
|
o = self.data[key]()
|
|
except KeyError:
|
|
return False
|
|
return o is not None
|
|
|
|
def __repr__(self):
|
|
return "<%s at %#x>" % (self.__class__.__name__, id(self))
|
|
|
|
def __setitem__(self, key, value):
|
|
self.data[key] = KeyedRef(value, self._remove, key)
|
|
|
|
def copy(self):
|
|
new = WeakValueDictionary()
|
|
for key, wr in self.data.copy().items():
|
|
o = wr()
|
|
if o is not None:
|
|
new[key] = o
|
|
return new
|
|
|
|
__copy__ = copy
|
|
|
|
def __deepcopy__(self, memo):
|
|
from copy import deepcopy
|
|
new = self.__class__()
|
|
for key, wr in self.data.copy().items():
|
|
o = wr()
|
|
if o is not None:
|
|
new[deepcopy(key, memo)] = o
|
|
return new
|
|
|
|
def get(self, key, default=None):
|
|
try:
|
|
wr = self.data[key]
|
|
except KeyError:
|
|
return default
|
|
else:
|
|
o = wr()
|
|
if o is None:
|
|
# This should only happen
|
|
return default
|
|
else:
|
|
return o
|
|
|
|
def items(self):
|
|
for k, wr in self.data.copy().items():
|
|
v = wr()
|
|
if v is not None:
|
|
yield k, v
|
|
|
|
def keys(self):
|
|
for k, wr in self.data.copy().items():
|
|
if wr() is not None:
|
|
yield k
|
|
|
|
__iter__ = keys
|
|
|
|
def itervaluerefs(self):
|
|
"""Return an iterator that yields the weak references to the values.
|
|
|
|
The references are not guaranteed to be 'live' at the time
|
|
they are used, so the result of calling the references needs
|
|
to be checked before being used. This can be used to avoid
|
|
creating references that will cause the garbage collector to
|
|
keep the values around longer than needed.
|
|
|
|
"""
|
|
yield from self.data.copy().values()
|
|
|
|
def values(self):
|
|
for wr in self.data.copy().values():
|
|
obj = wr()
|
|
if obj is not None:
|
|
yield obj
|
|
|
|
def popitem(self):
|
|
while True:
|
|
key, wr = self.data.popitem()
|
|
o = wr()
|
|
if o is not None:
|
|
return key, o
|
|
|
|
def pop(self, key, *args):
|
|
try:
|
|
o = self.data.pop(key)()
|
|
except KeyError:
|
|
o = None
|
|
if o is None:
|
|
if args:
|
|
return args[0]
|
|
else:
|
|
raise KeyError(key)
|
|
else:
|
|
return o
|
|
|
|
def setdefault(self, key, default=None):
|
|
try:
|
|
o = self.data[key]()
|
|
except KeyError:
|
|
o = None
|
|
if o is None:
|
|
self.data[key] = KeyedRef(default, self._remove, key)
|
|
return default
|
|
else:
|
|
return o
|
|
|
|
def update(self, other=None, /, **kwargs):
|
|
d = self.data
|
|
if other is not None:
|
|
if not hasattr(other, "items"):
|
|
other = dict(other)
|
|
for key, o in other.items():
|
|
d[key] = KeyedRef(o, self._remove, key)
|
|
for key, o in kwargs.items():
|
|
d[key] = KeyedRef(o, self._remove, key)
|
|
|
|
def valuerefs(self):
|
|
"""Return a list of weak references to the values.
|
|
|
|
The references are not guaranteed to be 'live' at the time
|
|
they are used, so the result of calling the references needs
|
|
to be checked before being used. This can be used to avoid
|
|
creating references that will cause the garbage collector to
|
|
keep the values around longer than needed.
|
|
|
|
"""
|
|
return list(self.data.copy().values())
|
|
|
|
def __ior__(self, other):
|
|
self.update(other)
|
|
return self
|
|
|
|
def __or__(self, other):
|
|
if isinstance(other, _collections_abc.Mapping):
|
|
c = self.copy()
|
|
c.update(other)
|
|
return c
|
|
return NotImplemented
|
|
|
|
def __ror__(self, other):
|
|
if isinstance(other, _collections_abc.Mapping):
|
|
c = self.__class__()
|
|
c.update(other)
|
|
c.update(self)
|
|
return c
|
|
return NotImplemented
|
|
|
|
|
|
class KeyedRef(ref):
|
|
"""Specialized reference that includes a key corresponding to the value.
|
|
|
|
This is used in the WeakValueDictionary to avoid having to create
|
|
a function object for each key stored in the mapping. A shared
|
|
callback object can use the 'key' attribute of a KeyedRef instead
|
|
of getting a reference to the key from an enclosing scope.
|
|
|
|
"""
|
|
|
|
__slots__ = "key",
|
|
|
|
def __new__(type, ob, callback, key):
|
|
self = ref.__new__(type, ob, callback)
|
|
self.key = key
|
|
return self
|
|
|
|
def __init__(self, ob, callback, key):
|
|
super().__init__(ob, callback)
|
|
|
|
|
|
class WeakKeyDictionary(_collections_abc.MutableMapping):
|
|
""" Mapping class that references keys weakly.
|
|
|
|
Entries in the dictionary will be discarded when there is no
|
|
longer a strong reference to the key. This can be used to
|
|
associate additional data with an object owned by other parts of
|
|
an application without adding attributes to those objects. This
|
|
can be especially useful with objects that override attribute
|
|
accesses.
|
|
"""
|
|
|
|
def __init__(self, dict=None):
|
|
self.data = {}
|
|
def remove(k, selfref=ref(self)):
|
|
self = selfref()
|
|
if self is not None:
|
|
try:
|
|
del self.data[k]
|
|
except KeyError:
|
|
pass
|
|
self._remove = remove
|
|
if dict is not None:
|
|
self.update(dict)
|
|
|
|
def __delitem__(self, key):
|
|
del self.data[ref(key)]
|
|
|
|
def __getitem__(self, key):
|
|
return self.data[ref(key)]
|
|
|
|
def __len__(self):
|
|
return len(self.data)
|
|
|
|
def __repr__(self):
|
|
return "<%s at %#x>" % (self.__class__.__name__, id(self))
|
|
|
|
def __setitem__(self, key, value):
|
|
self.data[ref(key, self._remove)] = value
|
|
|
|
def copy(self):
|
|
new = WeakKeyDictionary()
|
|
for key, value in self.data.copy().items():
|
|
o = key()
|
|
if o is not None:
|
|
new[o] = value
|
|
return new
|
|
|
|
__copy__ = copy
|
|
|
|
def __deepcopy__(self, memo):
|
|
from copy import deepcopy
|
|
new = self.__class__()
|
|
for key, value in self.data.copy().items():
|
|
o = key()
|
|
if o is not None:
|
|
new[o] = deepcopy(value, memo)
|
|
return new
|
|
|
|
def get(self, key, default=None):
|
|
return self.data.get(ref(key),default)
|
|
|
|
def __contains__(self, key):
|
|
try:
|
|
wr = ref(key)
|
|
except TypeError:
|
|
return False
|
|
return wr in self.data
|
|
|
|
def items(self):
|
|
for wr, value in self.data.copy().items():
|
|
key = wr()
|
|
if key is not None:
|
|
yield key, value
|
|
|
|
def keys(self):
|
|
for wr in self.data.copy():
|
|
obj = wr()
|
|
if obj is not None:
|
|
yield obj
|
|
|
|
__iter__ = keys
|
|
|
|
def values(self):
|
|
for wr, value in self.data.copy().items():
|
|
if wr() is not None:
|
|
yield value
|
|
|
|
def keyrefs(self):
|
|
"""Return a list of weak references to the keys.
|
|
|
|
The references are not guaranteed to be 'live' at the time
|
|
they are used, so the result of calling the references needs
|
|
to be checked before being used. This can be used to avoid
|
|
creating references that will cause the garbage collector to
|
|
keep the keys around longer than needed.
|
|
|
|
"""
|
|
return list(self.data)
|
|
|
|
def popitem(self):
|
|
while True:
|
|
key, value = self.data.popitem()
|
|
o = key()
|
|
if o is not None:
|
|
return o, value
|
|
|
|
def pop(self, key, *args):
|
|
return self.data.pop(ref(key), *args)
|
|
|
|
def setdefault(self, key, default=None):
|
|
return self.data.setdefault(ref(key, self._remove),default)
|
|
|
|
def update(self, dict=None, /, **kwargs):
|
|
if kwargs:
|
|
msg = ("Keyword arguments are not supported: "
|
|
"cannot create weak reference to 'str' object")
|
|
raise TypeError(msg)
|
|
d = self.data
|
|
if dict is not None:
|
|
if not hasattr(dict, "items"):
|
|
dict = type({})(dict)
|
|
for key, value in dict.items():
|
|
d[ref(key, self._remove)] = value
|
|
|
|
def __ior__(self, other):
|
|
self.update(other)
|
|
return self
|
|
|
|
def __or__(self, other):
|
|
if isinstance(other, _collections_abc.Mapping):
|
|
c = self.copy()
|
|
c.update(other)
|
|
return c
|
|
return NotImplemented
|
|
|
|
def __ror__(self, other):
|
|
if isinstance(other, _collections_abc.Mapping):
|
|
c = self.__class__()
|
|
c.update(other)
|
|
c.update(self)
|
|
return c
|
|
return NotImplemented
|
|
|
|
|
|
class finalize:
|
|
"""Class for finalization of weakrefable objects
|
|
|
|
finalize(obj, func, *args, **kwargs) returns a callable finalizer
|
|
object which will be called when obj is garbage collected. The
|
|
first time the finalizer is called it evaluates func(*arg, **kwargs)
|
|
and returns the result. After this the finalizer is dead, and
|
|
calling it just returns None.
|
|
|
|
When the program exits any remaining finalizers for which the
|
|
atexit attribute is true will be run in reverse order of creation.
|
|
By default atexit is true.
|
|
"""
|
|
|
|
# Finalizer objects don't have any state of their own. They are
|
|
# just used as keys to lookup _Info objects in the registry. This
|
|
# ensures that they cannot be part of a ref-cycle.
|
|
|
|
__slots__ = ()
|
|
_registry = {}
|
|
_shutdown = False
|
|
_index_iter = itertools.count()
|
|
_dirty = False
|
|
_registered_with_atexit = False
|
|
|
|
class _Info:
|
|
__slots__ = ("weakref", "func", "args", "kwargs", "atexit", "index")
|
|
|
|
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 __call__(self, _=None):
|
|
"""If alive then mark as dead and return func(*args, **kwargs);
|
|
otherwise return None"""
|
|
info = self._registry.pop(self, None)
|
|
if info and not self._shutdown:
|
|
return info.func(*info.args, **(info.kwargs or {}))
|
|
|
|
def detach(self):
|
|
"""If alive then mark as dead and return (obj, func, args, kwargs);
|
|
otherwise return None"""
|
|
info = self._registry.get(self)
|
|
obj = info and info.weakref()
|
|
if obj is not None and self._registry.pop(self, None):
|
|
return (obj, info.func, info.args, info.kwargs or {})
|
|
|
|
def peek(self):
|
|
"""If alive then return (obj, func, args, kwargs);
|
|
otherwise return None"""
|
|
info = self._registry.get(self)
|
|
obj = info and info.weakref()
|
|
if obj is not None:
|
|
return (obj, info.func, info.args, info.kwargs or {})
|
|
|
|
@property
|
|
def alive(self):
|
|
"""Whether finalizer is alive"""
|
|
return self in self._registry
|
|
|
|
@property
|
|
def atexit(self):
|
|
"""Whether finalizer should be called at exit"""
|
|
info = self._registry.get(self)
|
|
return bool(info) and info.atexit
|
|
|
|
@atexit.setter
|
|
def atexit(self, value):
|
|
info = self._registry.get(self)
|
|
if info:
|
|
info.atexit = bool(value)
|
|
|
|
def __repr__(self):
|
|
info = self._registry.get(self)
|
|
obj = info and info.weakref()
|
|
if obj is None:
|
|
return '<%s object at %#x; dead>' % (type(self).__name__, id(self))
|
|
else:
|
|
return '<%s object at %#x; for %r at %#x>' % \
|
|
(type(self).__name__, id(self), type(obj).__name__, id(obj))
|
|
|
|
@classmethod
|
|
def _select_for_exit(cls):
|
|
# Return live finalizers marked for exit, oldest first
|
|
L = [(f,i) for (f,i) in cls._registry.items() if i.atexit]
|
|
L.sort(key=lambda item:item[1].index)
|
|
return [f for (f,i) in L]
|
|
|
|
@classmethod
|
|
def _exitfunc(cls):
|
|
# At shutdown invoke finalizers for which atexit is true.
|
|
# This is called once all other non-daemonic threads have been
|
|
# joined.
|
|
reenable_gc = False
|
|
try:
|
|
if cls._registry:
|
|
import gc
|
|
if gc.isenabled():
|
|
reenable_gc = True
|
|
gc.disable()
|
|
pending = None
|
|
while True:
|
|
if pending is None or finalize._dirty:
|
|
pending = cls._select_for_exit()
|
|
finalize._dirty = False
|
|
if not pending:
|
|
break
|
|
f = pending.pop()
|
|
try:
|
|
# gc is disabled, so (assuming no daemonic
|
|
# threads) the following is the only line in
|
|
# this function which might trigger creation
|
|
# of a new finalizer
|
|
f()
|
|
except Exception:
|
|
sys.excepthook(*sys.exc_info())
|
|
assert f not in cls._registry
|
|
finally:
|
|
# prevent any more finalizers from executing during shutdown
|
|
finalize._shutdown = True
|
|
if reenable_gc:
|
|
gc.enable()
|