1 files changed, 385 insertions, 0 deletions
diff --git a/tests/bytecode/pylib-tests/weakref.py b/tests/bytecode/pylib-tests/weakref.py
new file mode 100644
index 0000000000..fcb6b74d1b
--- /dev/null
+++ b/tests/bytecode/pylib-tests/weakref.py
@@ -0,0 +1,385 @@
+"""Weak reference support for Python.
+
+This module is an implementation of PEP 205:
+
+http://www.python.org/dev/peps/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)
+
+from _weakrefset import WeakSet, _IterationGuard
+
+import collections  # Import after _weakref to avoid circular import.
+
+ProxyTypes = (ProxyType, CallableProxyType)
+
+__all__ = ["ref", "proxy", "getweakrefcount", "getweakrefs",
+           "WeakKeyDictionary", "ReferenceType", "ProxyType",
+           "CallableProxyType", "ProxyTypes", "WeakValueDictionary",
+           "WeakSet"]
+
+
+class WeakValueDictionary(collections.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, *args, **kw):
+        def remove(wr, selfref=ref(self)):
+            self = selfref()
+            if self is not None:
+                if self._iterating:
+                    self._pending_removals.append(wr.key)
+                else:
+                    del self.data[wr.key]
+        self._remove = remove
+        # A list of keys to be removed
+        self._pending_removals = []
+        self._iterating = set()
+        self.data = d = {}
+        self.update(*args, **kw)
+
+    def _commit_removals(self):
+        l = self._pending_removals
+        d = self.data
+        # We shouldn't encounter any KeyError, because this method should
+        # always be called *before* mutating the dict.
+        while l:
+            del d[l.pop()]
+
+    def __getitem__(self, key):
+        o = self.data[key]()
+        if o is None:
+            raise KeyError(key)
+        else:
+            return o
+
+    def __delitem__(self, key):
+        if self._pending_removals:
+            self._commit_removals()
+        del self.data[key]
+
+    def __len__(self):
+        return len(self.data) - len(self._pending_removals)
+
+    def __contains__(self, key):
+        try:
+            o = self.data[key]()
+        except KeyError:
+            return False
+        return o is not None
+
+    def __repr__(self):
+        return "<WeakValueDictionary at %s>" % id(self)
+
+    def __setitem__(self, key, value):
+        if self._pending_removals:
+            self._commit_removals()
+        self.data[key] = KeyedRef(value, self._remove, key)
+
+    def copy(self):
+        new = WeakValueDictionary()
+        for key, wr in self.data.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.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):
+        with _IterationGuard(self):
+            for k, wr in self.data.items():
+                v = wr()
+                if v is not None:
+                    yield k, v
+
+    def keys(self):
+        with _IterationGuard(self):
+            for k, wr in self.data.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.
+
+        """
+        with _IterationGuard(self):
+            for wr in self.data.values():
+                yield wr
+
+    def values(self):
+        with _IterationGuard(self):
+            for wr in self.data.values():
+                obj = wr()
+                if obj is not None:
+                    yield obj
+
+    def popitem(self):
+        if self._pending_removals:
+            self._commit_removals()
+        while True:
+            key, wr = self.data.popitem()
+            o = wr()
+            if o is not None:
+                return key, o
+
+    def pop(self, key, *args):
+        if self._pending_removals:
+            self._commit_removals()
+        try:
+            o = self.data.pop(key)()
+        except KeyError:
+            if args:
+                return args[0]
+            raise
+        if o is None:
+            raise KeyError(key)
+        else:
+            return o
+
+    def setdefault(self, key, default=None):
+        try:
+            wr = self.data[key]
+        except KeyError:
+            if self._pending_removals:
+                self._commit_removals()
+            self.data[key] = KeyedRef(default, self._remove, key)
+            return default
+        else:
+            return wr()
+
+    def update(self, dict=None, **kwargs):
+        if self._pending_removals:
+            self._commit_removals()
+        d = self.data
+        if dict is not None:
+            if not hasattr(dict, "items"):
+                dict = type({})(dict)
+            for key, o in dict.items():
+                d[key] = KeyedRef(o, self._remove, key)
+        if len(kwargs):
+            self.update(kwargs)
+
+    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.values())
+
+
+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.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:
+                if self._iterating:
+                    self._pending_removals.append(k)
+                else:
+                    del self.data[k]
+        self._remove = remove
+        # A list of dead weakrefs (keys to be removed)
+        self._pending_removals = []
+        self._iterating = set()
+        if dict is not None:
+            self.update(dict)
+
+    def _commit_removals(self):
+        # NOTE: We don't need to call this method before mutating the dict,
+        # because a dead weakref never compares equal to a live weakref,
+        # even if they happened to refer to equal objects.
+        # However, it means keys may already have been removed.
+        l = self._pending_removals
+        d = self.data
+        while l:
+            try:
+                del d[l.pop()]
+            except KeyError:
+                pass
+
+    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) - len(self._pending_removals)
+
+    def __repr__(self):
+        return "<WeakKeyDictionary at %s>" % 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.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.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):
+        with _IterationGuard(self):
+            for wr, value in self.data.items():
+                key = wr()
+                if key is not None:
+                    yield key, value
+
+    def keys(self):
+        with _IterationGuard(self):
+            for wr in self.data:
+                obj = wr()
+                if obj is not None:
+                    yield obj
+
+    __iter__ = keys
+
+    def values(self):
+        with _IterationGuard(self):
+            for wr, value in self.data.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):
+        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
+        if len(kwargs):
+            self.update(kwargs)