Mercurial > cpython-lru_cache-weakref

annotate Include/weakrefobject.h @ 87690:66c1c9f32567 default tip

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859
author Radomir Dopieralski <devel@sheep.art.pl>
date Tue, 03 Dec 2013 16:02:48 +0100
parents 1800107873c0
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1 /* Weak references objects for Python. */
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
2
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
3 #ifndef Py_WEAKREFOBJECT_H
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
4 #define Py_WEAKREFOBJECT_H
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
5 #ifdef __cplusplus
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
6 extern "C" {
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
7 #endif
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
8
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
9
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
10 typedef struct _PyWeakReference PyWeakReference;
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
11
33862
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
12 /* PyWeakReference is the base struct for the Python ReferenceType, ProxyType,
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
13 * and CallableProxyType.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
14 */
66664
62b61abd02b8 Merge branches/pep-0384.
Martin v. Löwis <martin@v.loewis.de>
parents: 65494
diff changeset
15 #ifndef Py_LIMITED_API
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
16 struct _PyWeakReference {
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
17 PyObject_HEAD
33862
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
18
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
19 /* The object to which this is a weak reference, or Py_None if none.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
20 * Note that this is a stealth reference: wr_object's refcount is
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
21 * not incremented to reflect this pointer.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
22 */
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
23 PyObject *wr_object;
33862
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
24
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
25 /* A callable to invoke when wr_object dies, or NULL if none. */
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
26 PyObject *wr_callback;
33862
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
27
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
28 /* A cache for wr_object's hash code. As usual for hashes, this is -1
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
29 * if the hash code isn't known yet.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
30 */
65494
e8969fb822fc make hashes always the size of pointers; introduce Py_hash_t #9778
Benjamin Peterson <benjamin@python.org>
parents: 44351
diff changeset
31 Py_hash_t hash;
33862
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
32
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
33 /* If wr_object is weakly referenced, wr_object has a doubly-linked NULL-
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
34 * terminated list of weak references to it. These are the list pointers.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
35 * If wr_object goes away, wr_object is set to Py_None, and these pointers
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
36 * have no meaning then.
facb5a2f4b53 SF 1055820: weakref callback vs gc vs threads
Tim Peters <tim.peters@gmail.com>
parents: 32472
diff changeset
37 */
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
38 PyWeakReference *wr_prev;
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
39 PyWeakReference *wr_next;
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
40 };
66664
62b61abd02b8 Merge branches/pep-0384.
Martin v. Löwis <martin@v.loewis.de>
parents: 65494
diff changeset
41 #endif
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
42
24752
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
43 PyAPI_DATA(PyTypeObject) _PyWeakref_RefType;
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
44 PyAPI_DATA(PyTypeObject) _PyWeakref_ProxyType;
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
45 PyAPI_DATA(PyTypeObject) _PyWeakref_CallableProxyType;
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
46
32472
4383db77b19a Make weak references subclassable:
Fred Drake <fdrake@acm.org>
parents: 30991
diff changeset
47 #define PyWeakref_CheckRef(op) PyObject_TypeCheck(op, &_PyWeakref_RefType)
4383db77b19a Make weak references subclassable:
Fred Drake <fdrake@acm.org>
parents: 30991
diff changeset
48 #define PyWeakref_CheckRefExact(op) \
44351
86a2679dca46 #1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT.
Christian Heimes <christian@cheimes.de>
parents: 42334
diff changeset
49 (Py_TYPE(op) == &_PyWeakref_RefType)
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
50 #define PyWeakref_CheckProxy(op) \
44351
86a2679dca46 #1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT.
Christian Heimes <christian@cheimes.de>
parents: 42334
diff changeset
51 ((Py_TYPE(op) == &_PyWeakref_ProxyType) || \
86a2679dca46 #1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT.
Christian Heimes <christian@cheimes.de>
parents: 42334
diff changeset
52 (Py_TYPE(op) == &_PyWeakref_CallableProxyType))
32472
4383db77b19a Make weak references subclassable:
Fred Drake <fdrake@acm.org>
parents: 30991
diff changeset
53
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
54 #define PyWeakref_Check(op) \
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
55 (PyWeakref_CheckRef(op) || PyWeakref_CheckProxy(op))
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
56
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
57
24752
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
58 PyAPI_FUNC(PyObject *) PyWeakref_NewRef(PyObject *ob,
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
59 PyObject *callback);
24752
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
60 PyAPI_FUNC(PyObject *) PyWeakref_NewProxy(PyObject *ob,
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
61 PyObject *callback);
24752
c1eb668525e1 Excise DL_EXPORT from Include.
Mark Hammond <mhammond@skippinet.com.au>
parents: 20287
diff changeset
62 PyAPI_FUNC(PyObject *) PyWeakref_GetObject(PyObject *ref);
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
63
66664
62b61abd02b8 Merge branches/pep-0384.
Martin v. Löwis <martin@v.loewis.de>
parents: 65494
diff changeset
64 #ifndef Py_LIMITED_API
39351
12ffed927a3d _PyWeakref_GetWeakrefCount() now returns a Py_ssize_t instead of long.
Neal Norwitz <nnorwitz@gmail.com>
parents: 33862
diff changeset
65 PyAPI_FUNC(Py_ssize_t) _PyWeakref_GetWeakrefCount(PyWeakReference *head);
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
66
30991
14d321466a06 SF bug 839548: Bug in type's GC handling causes segfaults.
Tim Peters <tim.peters@gmail.com>
parents: 24752
diff changeset
67 PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference *self);
66664
62b61abd02b8 Merge branches/pep-0384.
Martin v. Löwis <martin@v.loewis.de>
parents: 65494
diff changeset
68 #endif
30991
14d321466a06 SF bug 839548: Bug in type's GC handling causes segfaults.
Tim Peters <tim.peters@gmail.com>
parents: 24752
diff changeset
69
80759
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
70 /* Explanation for the Py_REFCNT() check: when a weakref's target is part
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
71 of a long chain of deallocations which triggers the trashcan mechanism,
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
72 clearing the weakrefs can be delayed long after the target's refcount
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
73 has dropped to zero. In the meantime, code accessing the weakref will
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
74 be able to "see" the target object even though it is supposed to be
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
75 unreachable. See issue #16602. */
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
76
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
77 #define PyWeakref_GET_OBJECT(ref) \
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
78 (Py_REFCNT(((PyWeakReference *)(ref))->wr_object) > 0 \
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
79 ? ((PyWeakReference *)(ref))->wr_object \
0748c22b37e5 Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Antoine Pitrou <solipsis@pitrou.net>
parents: 66664
diff changeset
80 : Py_None)
20280
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
81
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
82
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
83 #ifdef __cplusplus
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
84 }
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
85 #endif
97cfa461d793 The weak reference implementation, separated from the weakref module.
Fred Drake <fdrake@acm.org>
parents:
diff changeset
86 #endif /* !Py_WEAKREFOBJECT_H */